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Losses of lipid, protein and n−3 fatty acids in enriched Artemia franciscana starved at different temperatures
Abstract
The loss rates of protein and lipids were determined for enriched Artemia franciscana starved at different temperatures after enrichment. Following 12-h enrichment with DHA Selco (0.2 g l−1) at 28°C, the nauplii were temperature acclimated and transferred to starving condition (0–96 h; 5°C to 30°C).The total lipid content during enrichment increased from 145 mg g−1 dry weight (DW) (newly hatched nauplii) to 222 mg g−1 DW after 12 h. The DHA/EPA ratio reached an optimum after 12 h (1.85), where DHA and EPA constituted 12% and 6.7% of total fatty acids, respectively.When the nauplii were transferred to starving conditions the contents of all lipid components became reduced. The specific loss rate was found to be exponential for all components and significantly higher for DHA than for EPA and the sum of the other n−3 fatty acids. A. franciscana starved at the highest temperature (30°C) showed a loss rate of 92% day−1 (of DHA). Nauplii starved at 12°C had a loss rate of 51% day−1 (of DHA). At the same temperature (12°C) the corresponding loss rate of EPA, the sum of the other n−3 fatty acids and for the total lipid content was 15%, 30% and 11% day−1, respectively.The protein content was relatively stable in the nauplii kept at the lowest temperatures (5°C and 8°C), but as temperature increased, the loss rate of protein gradually increased reaching a loss rate of 28% day−1 in nauplii starved at 26°C. The survival of the nauplii was >67% throughout the starvation period (96 h), but at temperatures below 8°C and above 19°C, the survival was <13% after 96 h.Results show that the when Artemia nauplii are starved the lipid and protein content decreases as a function of temperature. This might affect the nutritional value of A. franciscana quite strongly if the nauplii reside in the fish tanks before being eaten by the larvae, or stored at ambient temperature before they are transferred to the fish tanks.
... Since, in fish hatcheries, Artemia is commonly hatched up to twice per day, then stored and provided to fish larvae in the next few feeding rounds until the next tour of Artemia hatching (Evjemo et al., 2001), we simulated these conditions in our study. Artemia was hatched every 12 h. ...
... Fish without swim bladder at this period has high energetic demands for feeding and maintenance of their position in water, which leads to high fish mortality (Summerfelt, 2013;Szkudlarek and Zakęś, 2007). This is of special relevance if we consider the fact that, in hatcheries, Artemia is commonly starved after hatching (Evjemo et al., 2001). This starvation may significantly reduce the caloric content of Artemia, including both protein and lipid content (Evjemo et al., 2001). ...
... This is of special relevance if we consider the fact that, in hatcheries, Artemia is commonly starved after hatching (Evjemo et al., 2001). This starvation may significantly reduce the caloric content of Artemia, including both protein and lipid content (Evjemo et al., 2001). In this research, 12 h starved live food treated with BGHO1/BGGO6-55 combination was presented with higher neutral lipid amount when compared to control 12 h starved Artemia. ...
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Weaning to inert diet in intensively reared pike-perch larvae is confronted with significant fish loss, which prevents successful commercialization of pike-perch production. Achievement of satisfactory feed quality and effective assimilation of nutrients by larval fish is the major challenge in larval production process. Aim of this study was to evaluate whether treatment of live and inert feed with lactobacilli could alleviate growth retardation associated with early weaning of pike-perch reared in recirculating system. Weaning started on 18th day post-hatching (DPH) either as sudden weaning (SW) or by co-administration of Artemia for six days (gradual weaning, GW). Prior to administration to fish, Artemia was treated with Lactobacillus salivarius BGHO1/Lb. reuteri BGGO6-55, while inert feed was treated with Lb. paracasei subsp. paracasei BGHN14/Lb. rhamnosus BGT10. Treatment with lactobacilli slightly raised neutral lipid level in Artemia nauplii, but significantly reduced their content in dry feed. Fish were sampled on the 24th DPH. Survival, morphometric indices, skeleton differentiation, digestive enzyme activity and opportunistic pathogenic bacteria level were assessed in whole fish specimens. GW fish were presented with better survival, body growth and phospholipase A2 (PLA2) activity. Alongside, Vibrio spp. growth was suppressed in these fish and skeleton development was improved, according to Alizarin Red staining and Col1A1/Sparc mRNA expression data. Lactobacilli application in GW fish correlated with an increase of survival, condition factor and growth rate, according to trypsin and chymotrypsin activities, indicating better utilization of dietary proteins for muscle building. In SW fish, lactobacilli elevated chymotrypsin activity, PLA2 to lipase activity ratio and improved survival and ossification, as evident from Alizarin Red staining and Col1A1/Sparc mRNA expression. This indicated improved fatty acid absorption and control of metamorphosis process. Furthermore, lactobacilli suppressed Vibrio spp. growth in SW fish. Aside from demonstrating the ability of lactobacilli to aid weaning in pike-perch larvae, this study indicated that different types of food treatment may direct fish growth in a predictable manner, allowing further cost-effective improvements of larval pike-perch rearing in intensive system.
... Therefore, embryos were sampled at several intervals (i.e. 0, 24,48,72,96,120,144,168,192,216,240,264,288 and 312 h) from each brooder. Organogenesis, developmental changes and physiological processes were recorded under a light microscope. ...
... In crayfish, time needed for egg development varies with temperature, suggesting the possibility of extending or reducing the incubation period [20]. In crustacean eggs, metabolic rate increases with temperature [21], which affects growth [22], survival [23], and yolk absorption rates [24]. However, high temperature could cause high mortality or serious deformities during egg incubation [25]. ...
... In the present study, deformities and abnormal sizes were not considered, although some deformed hatchlings were observed at 33°C that subsequently died. Crustaceans are highly sensitive to environmental changes during ontogeny, and are therefore at higher risk to reach lethal temperature during this period [24,38] report that the consumption rate of total lipid and protein in Artemia gradually increases as temperature increases. The higher lipid depletion rate at higher temperature occurs because lipids are the main source of energy during ontogeny of aquatic 36°C. ...
... In crustaceans, particularly in prawns (Manush et al. 2006), the time required for egg development varies with temperature, suggesting the possibility of extending or reducing the incubation period (García-Guerrero et al. 2003a). The metabolic rate increases with temperature (Naylor et al. 1999;García-Guerrero et al. 2003a;Jackson and Burford 2003), affecting growth (Jones 1994;García-Guerrero et al. 2003a), survival (Paula et al. 2001;García-Guerrero et al. 2003a), and yolk absorption rates (Evjemo et al. 2001;García-Guerrero et al. 2003a). However, high temperatures may cause mortality or deformities during egg incubation (Kumlu et al. 2000;García-Guerrero et al. 2003a;Manush et al. 2006). ...
... However, high temperatures may cause mortality or deformities during egg incubation (Kumlu et al. 2000;García-Guerrero et al. 2003a;Manush et al. 2006). Studies on poikilothermic aquatic animals, such as fish (Peterson et al. 1996;Ojanguren et al. 1999;Keckeis et al. 2001), crustaceans (Jones 1994;Verhoef and Austin 1999;Kumlu et al. 2000;Evjemo et al. 2001;Paula et al. 2001;García-Guerrero et al. 2003a), and mollusks (Gilroy and Edwards 1998;Forsythe et al. 2001) have shown different approaches to analyze the effects of temperature on egg development. One of the most accurate is to measure changes in lipid, protein, and carbohydrate biochemical composition during lecitotrophic development, which determines the utilization rate of every measured component (Lemos and Phan 2001;García-Guerrero et al. 2003a;Niu et al. 2003). ...
... As expected, higher temperature caused faster egg development, because it has a direct effect on physiological and biochemical processes (Brown and Terwilliger 1999;García-Guerrero 2003a). Because of the increase of temperature, there is a decrease in the duration of development as a consequence of a higher metabolic rate, a common response in crustaceans (Evjemo et al. 2001;Paula et al. 2001;García-Guerrero et al. 2003a). However, there are few studies that measure the depletion of proximate components at various temperatures during the embryonic development of lecitotrophic Decapoda, because most studies that analyze these components deal only with one temperature. ...
The influence of temperature on proximate composition of Macrobrachium americanum eggs during embryonic development was analyzed. Berried females were individually held at 19, 23, 26, and 31 C (three per temperature). Egg samples were obtained every 48 h for biochemical analysis from egg extrusion to hatching. Duration of development decreased with increasing temperature. At 19 and 31 C, a certain amount of both lipids and proteins was sustained during development. At 23 C, energy consumption seemed to rely mostly on lipids with low protein depletion. At 26 C, protein increase was detected while energy demand seemed to be supplied mostly by lipids. For carbohydrates, small amounts were always present in all treatments without a significant trend in either production or consumption. It is concluded that 23–26 C is the proper temperature range for M. americanum egg incubation, although 26 C might be better in terms of total energy consumption and protein usage.
... This food is known to be rich in total lipids, but low in long-chain fatty acids like DHA (Navarro et al., 1999;Narciso and Morais, 2001). As they develop, Artemia nauplii become depleted in lipids (Evjemo et al., 2001). Therefore, in aquaculture, Artemia are enriched with long-chain lipids using microalgae (Sargent et al., 1999;Evjemo et al., 2001;Copeman et al., 2002). ...
... As they develop, Artemia nauplii become depleted in lipids (Evjemo et al., 2001). Therefore, in aquaculture, Artemia are enriched with long-chain lipids using microalgae (Sargent et al., 1999;Evjemo et al., 2001;Copeman et al., 2002). Distribution of Artemia nauplii enriched with Isochrysis galbana increased the rate of metamorphosis in P. serratus (Wickins, 1972). ...
Seasonal variations in environmental conditions determine the success of decapod larval development, and females transmit more energy in sub-optimal conditions to maximise the fitness of their offspring. The objective of this study was to focus on the combined effects of temperature (14, 18 and 22 °C) and food quality on the performance of larvae produced by 5 young (0+) and 5 old (I+) Palaemon serratus females. We prepared 3 diets based on Artemia, in decreasing order of total fatty acid content: freshly hatched nauplii (N), unenriched met-anauplii (M) and metanauplii enriched with a mixture of microalgae (ME). At hatching, the larvae produced by I+ females had a higher biomass but a similar fatty acid concentration to those produced by 0+ females. Larvae survived better and developed relatively faster as temperature increased, and the longer they waited to meta-morphose, the greater their weight at metamorphosis. These performances were diet-dependent, with more survival and more growth in less time with diet N than with the other two. Larvae from I+ females performed better than those from 0+ females, especially under the most stressful conditions. The greater biomass of the larvae of I+ females seems to have enabled them to follow a shorter, and therefore faster, development path than those of 0+ females. The larvae's diet also had an impact on post-metamorphic composition: larvae eating a diet richer in fatty acids produced richer juveniles and those eating a poorer diet produced juveniles with slightly more essential fatty acids. This study supports the high plasticity of caridean shrimp larval development and the importance of maternal effects on the fitness of offspring.
... LA influenced the values of this parameter, although to a lesser extent than time, which can be explained by the fact that the animals were fasting. In this situation, the available protein is likely to be used as an energy source and reduced to amino acids for the resynthesis of protein or for the production of osmolytes such as taurine, which is synthesized from methionine [45][46][47]. Given that the protein concentration patterns of the LA-treated groups changed at different exposure times compared with SCtrl (Figure 3a), it is possible to consider the interactions between the developmental stage of artemia and LA as a metabolic modulator. ...
... In artemia, most lipid fractions are stored as neutral lipids (80%), with triglycerides representing approximately 70% [52]. Triglyceride utilization is mainly divided into the synthesis of structural lipids and the supply of free fatty acid for energy production [45]. Although these results do not show a significant effect of LA on triglyceride concentration, unlike other existing studies [11,53], similar responses to those found herein have been observed in other aquatic animal species, including crustaceans. ...
Lipoic acid (LA) is a mitochondrial coenzyme that, depending on the concentration and exposure time, can behave as an antioxidant or pro-oxidant agent and has a proven ability to modulate metabolism by promoting lipid and glucose oxidation for energy production. To assess the effects of LA on energy metabolism and redox balance over time, Artemia sp. nauplii was used as an animal model. The administered concentrations of the antioxidant were 0.05, 0.1, 0.5, 1.0, 5.0, and 10.0 µM. Therefore, possible differences in protein, triglyceride, glucose, and lactate concentrations in the artemia samples and total ammoniacal nitrogen (TAN) in the culture water were evaluated. We also measured the effects of LA on in vivo activity of the electron transport system (ETS), antioxidant capacity, and production of reactive oxygen species (ROS) at 6, 12, 18, and 24 h post-hatching. There was a decrease in glucose concentration in the LA-treated animals, and a decrease in ammonia production was observed in the 0.5 µM LA treatment. ETS activity was positively regulated by the addition of LA, with the most significant effects at concentrations of 5.0 and 10.0 µM at 12 and 24 h. For ETS activity, treatments with LA presented the highest values at 24 h, a period when ROS production decreased significantly, for the treatment with 10.0 µM. LA showed positive regulation of energy metabolism together with a decrease in ROS and TAN excretion.
... TOMAS eT Al. of global warming (Byrne, Foo, Ross, & Putnam, 2020;Duarte, 2014;Foo & Byrne, 2017). An increase in temperature clearly leads to an increase in the metabolic rate (Allan et al., 2006) along with changes in energy reserve consumption (Evjemo, Danielsen, & Olsen, 2001;. ...
... There have been a considerable number of studies demonstrating that high temperatures induce an increment on metabolic rate (oxygen consumption increase), affecting all the biochemical and physiological processes (Brown & Terwilliger, 1999), such as growth rate (Abdelrahman et al., 2019;Anger, 2001;Jones & Romaire, 1995;Petriella & Boschi 1997;Thomas et al., 2000) and survival Hamasaki, Sugizaki, Dan, & Kitada, 2009;Nurdiani & Zeng, 2007). The higher metabolic rate is accompanied by great consumption of energy reserves, mainly lipid and protein content (Evjemo et al., 2001;García-Guerrero 2010). As it was mentioned above, at 28ºC, significant lipid depletion was detected in N. davidi 8 | TOMAS eT Al. ...
This study analysed the effects of three temperatures (20, 24 and 28ºC) on survival, body coloration, carotenoid content, body weight, biochemical composition and spermatophore quality in the shrimp Neocaridina davidi. In all treatments, survival was >90%. Female body coloration and total carotenoid content, for both males and females, did not statistically differ among treatments. Female weight was similar for the three temperatures, while male weight was higher at 20ºC and 24ºC. Total lipid content was higher in female and male shrimps raised at 20ºC. Total protein content was higher in females exposed at 28ºC, but in contrast, males showed the lowest value at the same temperature. The histological and histochemical analyses of the male reproductive system did not reveal differences among treatments. At 20ºC, a delay in ovaries maturation was observed, as well as a smaller amount of ovigerous females at the end of the experimental period. Hence, these results suggest that a temperature range from 20ºC to 28ºC is adequate for satisfactory growth, with no change being exerted on spermatophore quality, body female coloration or carotenoid content, but biochemical composition was affected. Nevertheless, the lowest temperature had a clear impact on the metabolism and reproduction of N. davidi.
... To overcome the lack of ω-3 HUFA in Artemia nauplii, various enrichment techniques have been developed (Han et al. 2000). The supplements or enrichments may include essential fatty acids (Ando et al. 2004;Bransden et al. 2005;Czesny et al. 1999;Evjemo et al. 2001;Han et al. 2000;Hanaee et al. 2005;McEvoy et al. 1998;Monroig et al. 2006;Monroig et al. 2007;Payne and Rippingale 2000;Robin 1998;Tonheim et al. 2000;Woods 2003), steroid hormones (Stewart et al. 2001), enrofloxacin (Roque and Gomez-Gil 2003), vitamins (Monroig et al. 2007), the diatom Chaetoceros muelleri (Ritar et al. 2004), and probiotics including Pediococcus acidilactici and Saccharomyces cerevisiae (Gatesoupe 2002), Lactobacillus sporogenes (Venkat et al. 2004), and Bacillus spp. (Ziaei-Nejad et al. 2006). ...
... In our study, the encapsulation time of 48 h was longer than that in other studies conducted by Moren et. al (2005), Evjemo et al. (2001), Han et al. (2000) and Ritar et al. (2004). Artemia enrichment periods vary with different enrichment probiotics (Gatesoupe 1991 In this study, the best encapsulation period of Artemia was 48 h using a medium of OW and TSB at 75:25 v/v with the probiotics P. synxantha and P. aeruginosa at ratio of 30:70 v/v respectively and at the same inoculum of 10 5 CFU/mL. ...
... The reason for the difference in fatty acid composition between the Artemia types may have been that the higher bioavailability of the high MAG emulsion, which can be regarded as partly digested, would lead to a more rapid absorption of this emulsion in the Artemia. Since especially DHA, but also EPA, are rapidly metabolised in Artemia (Evjemo et al., 2001), an enhanced uptake rate would lead to a more rapid decrease in the concentrations of these fatty acids in Artemia, the larger difference in DHA concentration than in EPA concentration corresponding to the different rate of reconversion of the two fatty acids (Evjemo et al., 2001). ...
... The reason for the difference in fatty acid composition between the Artemia types may have been that the higher bioavailability of the high MAG emulsion, which can be regarded as partly digested, would lead to a more rapid absorption of this emulsion in the Artemia. Since especially DHA, but also EPA, are rapidly metabolised in Artemia (Evjemo et al., 2001), an enhanced uptake rate would lead to a more rapid decrease in the concentrations of these fatty acids in Artemia, the larger difference in DHA concentration than in EPA concentration corresponding to the different rate of reconversion of the two fatty acids (Evjemo et al., 2001). ...
High levels of n-3 polyunsaturated fatty acids and a low level of arachidonic acid (ARA, 20:4n-6) in larval diets seem to be necessary for normal pigmentation of Atlantic halibut juveniles, whereas energy status and fatty acid composition seem to modulate eye migration in flatfish in general. However, we do not know the limits or the critical combinations of essential fatty acids that will give normal development of the larvae. In the present study we fed Atlantic halibut larvae enriched Artemia with small differences in fatty acid composition. Artemia enriched with the high TAG (triacylglycerol) emulsion contained average eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) of 13.9 and 12.5% of total fatty acids, respectively, while in Artemia enriched with the high MAG (monoacylglycerol) emulsion, the levels were 12.9 and 9.4%. The fatty acid composition of the larvae reflected the composition of Artemia, in addition ARA was slightly lower in the high TAG than in the high MAG enriched Artemia, i.e. 3.7–4.0 and 4.2–4.3% of total fatty acids, respectively. There were no differences in lipid level, measured as fatty acid methyl esters, neither between the Artemia types, nor between the larval groups. The percentages of normal pigmentation in Atlantic halibut juveniles that had been fed the high TAG and high MAG enriched Artemia were 77±2 and 46±16%, respectively, the eye migration was also slightly better in the high TAG group, but the final weight was lowered from 1.98±0.17 g in the high MAG group to 1.56±0.13 g in the high TAG group. There was a correlation between pigmentation and eye migration, since fish where the left eye had passed the mid-dorsal ridge did not get pigmentation on the blind side. It is concluded that DHA in larval whole body should be higher than 13% of total fatty acids to obtain normal pigmentation in Atlantic halibut larvae when the EPA:ARA ratio is approximately 3.5. The differences in fatty acid composition in the present study had only minor effects on eye migration.
... This was equivalent to Artemia ingesting an LSB ration equivalent to 4.4% of total body dry weight, although the actual ingested ration might have been higher because losses of riboflavin from the beads and Artemia were not considered or investigated. The lipid content of newly hatched Artemia (A. franciscana) is 145 mg g − 1 dry weight (Evjemo et al., 2001) while the lipid content of enriched Artemia is reported to be 220-250 mg g − 1 dw (Evjemo et al., 2001;Van der Meeren, 2003). Therefore, lipid in LSB ingested to increase the riboflavin content with 281 mg kg − 1 would represent 18 to 30% of the total lipid content of the Artemia (dw). ...
... This was equivalent to Artemia ingesting an LSB ration equivalent to 4.4% of total body dry weight, although the actual ingested ration might have been higher because losses of riboflavin from the beads and Artemia were not considered or investigated. The lipid content of newly hatched Artemia (A. franciscana) is 145 mg g − 1 dry weight (Evjemo et al., 2001) while the lipid content of enriched Artemia is reported to be 220-250 mg g − 1 dw (Evjemo et al., 2001;Van der Meeren, 2003). Therefore, lipid in LSB ingested to increase the riboflavin content with 281 mg kg − 1 would represent 18 to 30% of the total lipid content of the Artemia (dw). ...
Lipid spray beads (LSB) containing high concentrations of phospholipids were produced in order to improve their dispersion in both fresh and saltwater. The beads were developed to deliver both fat-soluble and water-soluble micronutrients to Artemia and other suspension feeders. LSB were prepared by spraying molted lipid into a chamber that was cooled with liquid nitrogen in order to solidify the lipid beads. Addition of soy lecithin to LSB did not affect retention of glycine when the beads were suspended in distilled water. There was an initial loss of 80% incorporated glycine after LSB were suspended in water for 20min. Artemia readily ingested riboflavin-containing LSB and their full guts were evident within 30min of feeding. The riboflavin content of Artemia could be increased from 55± 0.6 mg kg−1 (dw) to 329±62 mg kg−1 (dw) after 1h enrichment. LSB prepared with phospholipids are promising vehicles for enrichment of suspension-feeding organisms used as feed for larval marine fish and crustaceans as well as other suspension feeders.
... The pattern of use of the yolk reserve after hatching varies considerably among prawn species (Evjemo et al., 2001;García-Guerrero, 2010). Some prawn species are prone to massive mortalities at the start of exogenous feeding during the nonlecithotrophic period (Kailasam et al., 2007;Lal et al., 2014). ...
Macrobrachium macrobrachion is an African native brackish river prawn with a high commercial value. Currently, there is little information on the post-larval production of this species. Two experiments were conducted in the laboratory to develop production techniques for this species. The first experiment analyzed the duration of yolk resorption and the second described the larval stages. Yolk resorption was studied in 240 newly hatched larvae for 24 h based on the reduction in yolk area over time. For larval development stages, six breeding tanks containing 100 L with a density of 50 larvae/L were used. Larvae were fed a combination of Artemia nauplii, Brachionus plicatilis, and pelleted food (Larviva ProStart, Biomar Efico). The results have shown that the area of yolk reserves varied significantly in the hours after hatching. At 14 h after hatching, each larva resorbed approximately 85% of its yolk reserve, and at 18 h after hatching, each of them still had approximately 6.1%. Twelve larval stages were identified and described in three critical stages. M. macrobrachion larvae are lecithotrophic and need to start exogenous feeding for 14 h at the earliest and 18 h at the latest after hatching. These results are the first to highlight the potential for mass production of brackish river prawn prawns.
... Since commonly used oil emulsions are aimed at fatty acid enrichment, they often do not supplement with proteins or other nutrients. In fact, it has been reported that enriching GSL Artemia with an oil emulsion (DHA Selco, INVE) similar to the one used in this study led to a 19% reduction in proteins compared with newly hatched nauplii (Evjemo et al., 2001). Proteins are known as a key nutrient for crustaceans, especially during larval development when rapid tissue synthesis occurs (Anderson & De Silva, 2011;Anger, 2001). ...
Decorator crab Camposcia retusa is a popular marine ornamental species; however, it has never been bred previously. To establish a feeding regime for C. retusa larvae, which include two zoeal and a megalopal stage, three experiments were conducted. In all experiments, ≥60% of unfed 1st zoeal (Z1) larvae survived to the next stage, combined with the orange guts observed in larvae fed Artemia, suggesting Z1 larvae are facultative lecithotrophic. Experiment 1 evaluated the suitability of ss‐type rotifer Brachionus rotundiformis as prey. Z1 larvae were fed rotifer at a density from 0 to 90 ind./ml. There was no significant difference in Z1 survival among treatments (56.7–68.3%, p > 0.05); therefore, ss‐type rotifer is considered an unsuitable prey for the larvae. Experiment 2 examined the suitability and optimal density of Artemia nauplii, and co‐feeding copepod Pavocalanus crassirostris with Artemia, for larval rearing. The larvae fed 10 Artemia/ml had the highest survival to megalopae (91.3 ± 3.1%, p < 0.05). However, high mortality occurred in megalopae, resulting in poor survival to the 1st crab stage (1.3%–12.5%) in all treatments (p > 0.05). Meanwhile, co‐feeding copepods with Artemia showed significantly inferior survival and development to megalopae when compared to that of 10 Artemia/ml treatment. Experiment 3 evaluated the effects of Artemia enrichment on larval performance. The results suggested that Artemia enrichment did not improve larval survival or development. Based on our results, Artemia nauplii fed at 10 ind./ml throughout larval development appears to be appropriate for C. retusa.
... Besides fatty acids, fish larvae also have a high dietary requirement of protein, because larval growth is mainly determined by muscle protein deposition (Carter and Houlinhan, 2001;Conceição et al., 2010;Rønnestad et al., 2003). However, the energy and nutrition contents continue to decrease in Artemia as the nauplii develop into metanuplii (Léger et al., 1987;Navarro et al., 1999;Vanhaecke et al., 1983); in fact, the GSL Artemia nauplii were reportedly lost around 19% of protein after being enriched for 12 h in a similar oil emulsion product (DHA Selco) as used in this present study (Evjemo et al., 2001). Although the oil emulsion product (S.Presso®) used in present study boosted the lipids contents in Artemia, it had little supplementation of protein. ...
Marine finfish hatcheries often replace small live prey with the larger traditional prey, brine shrimp Artemia, to feed the growing fish larvae. However, research on fish larviculture, including marine ornamental fish, often overlooks the importance of fine-tuning such prey transition. This study investigated the suitable time and approach for the larvae of an ornamental species, orchid dottyback Pseudochromis fridmani, to transit to the Artemia feeding phase. In experiment I, the suitable prey shift time window was estimated by abruptly feeding P. fridmani larvae with newly hatched Artemia nauplii (AN) from 5, 8, 11 or 14 days post-hatching (DPH) until 19 DPH. Although P. fridmani could ingest AN from 5 DPH, the final larval survival of 11-DPH and 14-DPH treatments were significantly higher, and it might relate to the enhanced digestive capability of older larvae. In experiment II, when prey shift began on 9, 11, or 13 DPH, the larvae were either abruptly shifted (AS) to AN feeding, or given a three-day gradual transition (GT) period of co-feeding original prey (rotifers and copepods) with AN before completing the prey switch. By 22 DPH, the prey shift strategy of GT significantly improved larval survival compared to the AS treatments; prey shift time treatments of 11-DPH and 13-DPH also reached significantly higher survival than 9-DPH treatments. However, survival of all individual treatments continued to decrease in the final stage of experiment. To further improve the prey transition success, experiment III investigated the effects of Artemia enrichment and prey shift time, by abruptly feeding larvae with either AN or enriched Artemia metanauplii (EA) from 9, 11, or 13 DPH onwards. Although the larvae fed AN were significantly larger than those fed EA, the absolute differences were small. There was a significant interaction between Artemia type and prey shift time on larval survival. The EA-11-DPH and EA-13-DPH treatments maintained steady survival post prey transition, and reached the highest mean survival of 58 ± 10%, and 55 ± 12% by 20 DPH, respectively. Moreover, while the larvae fed AN abnormally reduced prey intake over time, most larvae in EA-11-DPH and EA-13-DPH treatments still maintained high Artemia ingestion. These results suggest that dietary highly unsaturated fatty acids in enriched Artemia were crucial for larval survival of P. fridmani. Overall, this study shows that P. fridmani larvae could skip AN and directly feed on EA from 11 DPH without compromising survival or feeding performance.
... Under the increased temperature, the rate of metabolic processes hiked, demanding more energy, and causes the early depletion of energy reserve. The influence of temperature on the utilization of yolk content was reported in several aquatic species [36][37][38] During the stressful condition, organisms try to maintain its homeostasis. The capacity of controlling cardiovascular function is one such function to maintain the organism's oxygen consumption rate and activity of the organism 39 . ...
Global climate change is transforming life on earth, causing widespread effects on all ecosystems. Among marine ecosystems, estuaries are considered as nursery grounds for marine and fresh water species. M. rosenbergii , a euryhaline species, migrate to the estuaries for breeding and spawning. The subsequent larval rearing takes place by experiencing variations in temperature and salinity conditions. The present study examines the effect of different temperature and salinity on the larval development and survival by observations on stored yolk utilization, cardiac performance, as well as changes in the rate of growth in body appendages and larval activity. The larvae showed 100% mortality at higher temperature (33.5 ± 0.5 °C) in all the salinity conditions (12 PPT, 15 PPT, and 20 PPT). The survival rate varied between 76-96 % on exposure to lesser temperature conditions. Likewise, the post-embryonic yolk lasted for 4 days at ambient temperature (29 °C); whereas, at 33.5 ± 0.5 °C, it lasted only for 2-3 days. There was an increase in total length of larvae, when exposed to higher temperature and salinity, independently or in combination, but at 33.5 ± 0.5 °C under all salinity conditions the larvae died on the 5 th day. For the cardiac performance, larval heart beat ( f H ) significantly increased for higher temperature and salinity conditions (20 PPT; 33.5 °C) and lowered at ambient condition 12 PPT; 29°C. Larval stroke volume V s , and Cardiac output Q□ were higher in ambient conditions and lowest in higher temperature and salinity conditions. However, temperature and salinity together did not show any significant effect on cardiac performance. On the other hand, the larval activity decreased significantly at higher temperature and salinity conditions, compared to ambient conditions but the interactive effect did not show any change. Thus, the physiological responses to temperature and salinity by the early life stages of M. rosenbergii could restrain the tolerance capability of the organism, thereby interfering in the successful completion of the larval development under the altered climatic conditions.
... The quantity of microalgae remaining in the digestive system of enriched Artemia nauplii during a certain period of time, reflected by the gut fullness in this work, is relevant to evaluate the effectiveness of the enrichment treatment. On one hand, starvation occurring just after enrichment of Artemia nauplii results in a progressive decline of gut and tissue nutrient reserves and on a change of their nutritional value over the time 58 . Since larvae from some crustacean decapods, such as Jasus edwarsii, tear enriched Artemia into pieces previous to their ingestion, causing the loss of its microalgal gut contents, attention has been focused on their relative contribution to the overall biochemical composition of nauplii and juveniles of the species 59 . ...
The southern surf crab Ovalipes trimaculatus (de Haan, 1833) presents a high potential for aquaculture. In this study, we analyze the benefits of different dietary treatments on its molt success and fitness of larval stages. Artemia persimilis nauplii were enriched with monospecific (Nannochloropsis oculata, Tetraselmis suecica, Dunaliella salina, Isochrysis galbana and Chaetoceros gracilis) and multispecific (Mix) microalgal diets twice a day over a 48-h period. Mean total length (TL), growth instar number (I) and gut fullness rate (GFR) of nauplii showed significant differences between dietary treatments at several sampling times, optimal results being observed in those providing Mix. Artemia nauplii grown under most experimental dietary treatments reached the capture size limit for Ovalipes trimaculatus zoea I (700 µm) within 24 h. After that time interval, Mix-enriched nauplii were amongst those with higher protein contents. Ovalipes trimaculatus zoea I fed on Artemia nauplii enriched during 24 h under different dietary treatments showed significant differences in survival, inter-molt duration, molting success to zoea II and motility. Optimal results were observed in zoea I fed on Mix-enriched Artemia nauplii. This work not only represents a first step towards the dietary optimization for O. trimaculatus zoeae rearing but also provides the first results on the use of enriched A. persimilis.
... In support of this assumption, Artemia nauplii treated with lactobacilli at 0-24 th h regimen were presented with negative correlation between free amino acid and protein amount, on one side, and unsaturated lipids, on the other side. This reflects parallel use of both proteins/free amino acids and fatty acids as energetic sources by starved Artemia nauplii, as demonstrated previously (Evjemo et al., 2000). Although, according to this interpretation, lipid reserves of 0-24 th h treated Artemia nauplii were lowered during hatching, no overall decrease of neutral lipid amount in comparison to control was observed with none of 500 g/kg combinations. ...
This study aimed to analyze an impact of Lactobacillus salivarius BGHO1 and Lactobacillus reuteri BGGO6-55 supplemented to Artemia franciscana cultivation medium on biochemical profile of hatched nauplii. Impacts of different BGHO1:BGGO6-55 ratios (75:25, 50:50 and 25:75) and their total concentrations (250 and 500 g/kg of Artemia cysts) at different timings of bacteria application (pre- and post-hatching) were examined. The effects were evaluated by quantification of naupliar peptide, soluble protein, phospho-, neutral and unsaturated lipid content. Uni and multi-factorial analysis of variance (ANOVA) were used to estimate the effects of treatments relative to control and to model factor interactions, respectively Statistical analysis indicated that post-hatching application of 75:25 strain ratio at high dose was associated with an increase of neutral lipid amount. Furthermore, factor interaction profiling identified positive correlation of lactobacilli concentration with the level of free amino acids/short peptides, phospho-, neutral and unsaturated lipids, but only at 50:50 strain ratio combination. Application of lower lactobacilli dose at 75:25 strain ratio caused an increase of soluble protein and phospholipid amount. Hypothetically, graded response of Artemia nauplii to lactobacilli supplementation was induced with different BGHO1 doses. It assumedly ranged from stress-response protein synthesis at lower doses to membrane permeability alterations and triglyceride-mediated defense mechanism activation at higher BGHO1 doses. In contrast to lactobacilli supplementation after Artemia hatching, pre-hatching application of lactobacilli was not associated with an increase of Artemia nutritive profile, though again there was a positive association of lactobacilli concentration with nutrient amount. This implicates interference of lactobacilli with the hatching process. Results presented here facilitate the design of future studies aiming to modify Artemia nutritive profile in accordance with nutritional demands of cultivated fish species.
... FIJs of J. edwardsii were estimated to be using on average 0.28 ± 0.02 mg d −1 of lipid and 0.59 ± 0.05 mg d −1 of protein, while in S. verreauxi the estimated lipid use was 0.110 ± 0.003 mg d −1 and protein use was 0.31 ± 0.01 mg d −1 . The rate of lipid being consumed during starvation in FIJs of S. verreauxi over a 6°C temperature range was the same, unlike in larval stages of the crayfish Cherax quadricarinatus and the fairy shrimp Artemia franciscana, where lipid was used faster at higher temperatures (Evjemo et al. 2001, García-Guerrero et al. 2003. ...
... Within biologically relevant ranges, temperature drives exponential changes in organismal metabolic rates (Gillooly et al. 2001;Brown et al. 2004), which in turn influence animal biochemical composition and elemental content (Woods et al. 2003;Bullejos et al. 2014). For example, higher temperatures can reduce cellular RNA and P demands due to increased ribosomal translational efficiencies (Sievers et al. 2004;Toseland et al. 2013) and decrease body lipid stores by increasing C respiration (Evjemo et al. 2001;McFeeters and Frost 2011;Alcaraz et al. 2013) leading to proportional changes in consumer body C:P ratios. Further, by influencing consumer life-history trait expression and elemental composition, temperature can also affect population growth rates and regulate elemental flows through ecosystems (Petchey et al. 1999;Savage et al. 2004). ...
Food quality and temperature can affect zooplankton production in lakes by altering organismal metabolism. However, the influence of these factors on consumer nutritional physiology and population biomass remains relatively understudied in natural populations. Here, we examined seasonal changes in body stoichiometry, biochemistry, and population biomass in two Daphnia species collected from two separate lakes differing in dietary phosphorus (P) supply. Food quality, measured as seston carbon:P (C:P) ratios, varied throughout the study in each lake, and water temperatures generally increased across the growing season. Daphnid elemental composition was correlated with food quality in both populations, but relationships between daphnid body stoichiometry and temperature were consistently stronger as Daphnia body C:P ratios and content of major biochemical pools declined simultaneously throughout the summer, which largely coincided with increased water temperatures. Warmer temperatures were associated with relaxed %P-RNA coupling as daphnid body RNA content declined and P content remained relatively high. These responses combined with temperature related decreases in Daphnia body %lipids and %C appeared to explain declines in daphnid body C:P ratios in both lakes over the growing season. Seasonal changes in population biomass were related to both food quality and water temperature in the lower nutrient lake. Biomass production under more eutrophic conditions however was unrelated to food quality and was instead associated with seasonal temperature changes in the higher nutrient lake. Overall, our study shows that seasonal changes in temperature and resource quality may differentially affect consumer stoichiometry and biomass production in lake ecosystems by altering consumer elemental metabolism. © 2018 Association for the Sciences of Limnology and Oceanography.
... In this regard, enrichment techniques, which take advantage of the non-selective feeding habit of Artemia sp, with oil emulsions are used for enhancing the n-3 LC-PUFA content of this live food. However, because of high catabolism of n-3 LC-PUFA in Artemia, adequate enrichment of these fatty acids is difficult (Evjemo et al., 2001). ...
A 15-day study was conducted to evaluate the effects of Artemia metanauplii enrichment with two commercial supplements (Easy DHA-Selco and S.presso) which contained high levels of n–3 long chain polyunsaturated fatty acids (n–3 LC-PUFA) on growth performance, stress resistance and fatty acid profile of Litopenaeus vannamei post larvae (PL). In this regard, PL were fed with three different types of Artemia including: (1) newly hatched Artemia franciscana nauplii, which served as a control group; (2) Artemia metanauplii enriched with Easy DHA-Selco; and (3) Artemia metanauplii enriched with S.presso. Survival rate did not change among different groups. PL fed Artemia enriched with the S. presso and the Easy DHA-Selco showed the highest wet and dry weight, respectively (P < 0.05). Moreover, PL fed Artemia enriched with the commercial emulsions had higher survival rate (~ 10 %) than PL fed newly hatched Artemia (P < 0.05). The concentration of n–3 PUFA especially DHA and also n-3 / n-6 PUFA ratios were higher in PL fed with Artemia enriched with the commercial emulsions than the control group. From above mentioned results, feeding enriched Artemia with n–3 LC-PUFA is recommended for larval stages of L. vannamei.
... The relative importance of several metabolic reserves and the order of utilization varies among species [1,35]. In some crustaceans, proteins appear the main energy source during food deprivation [36,37] or lipids [38][39][40] or both simultaneously [36]. ...
The utilization of storage lipids and their associated fatty acids (FA) is an important means for organisms to cope with periods of food shortage, however, little is known about the dynamics and FA mobilization in benthic copepods (order Harpacticoida). Furthermore, lipid depletion and FA mobilization may depend on the ambient temperature. Therefore, we subjected the temperate copepod Platychelipus littoralis to several intervals (3, 6 and 14 days) of food deprivation, under two temperatures in the range of the normal habitat temperature (4, 15°C) and under an elevated temperature (24°C), and studied the changes in FA composition of storage and membrane lipids. Although bulk depletion of storage FA occurred after a few days of food deprivation under 4°C and 15°C, copepod survival remained high during the experiment, suggesting the catabolization of other energy sources. Ambient temperature affected both the degree of FA depletion and the FA mobilization. In particular, storage FA were more exhausted and FA mobilization was more selective under 15°C compared with 4°C. In contrast, depletion of storage FA was limited under an elevated temperature, potentially due to a switch to partial anaerobiosis. Food deprivation induced selective DHA retention in the copepod’s membrane, under all temperatures. However, prolonged exposure to heat and nutritional stress eventually depleted DHA in the membranes, and potentially induced high copepod mortality. Storage lipids clearly played an important role in the short-term response of the copepod P. littoralis to food deprivation. However, under elevated temperature, the use of storage FA as an energy source is compromised.
... Therefore, live foods continue to be essential for the first feeding of marine fish larvae because they lead to increased feeding, stimulate enzyme secretion, and result in consistently good growth and survival. Nevertheless, some disadvantages have been pointed out concerning the use of live foods: (1) the production and use of live foods is expensive (Hart and Purser, 1996); (2) bacteria associated with zooplankton cultures can be detrimental to fish larvae and may act as vectors of diseases; (3) the nutritional values of live foods can be highly variable (Evjemo, et al., 2001 and Olsen, 2004); (4) nutritional quality of live foods is difficult to manipulate (5) metabolites from zooplankton increase the load on fish rearing systems; (6) fine-mesh outlet screens are required to retain zooplankton so low water flow rates are necessary to avoid screen blockages and resultant tank overflows. For these reasons it is considered highly desirable to use artificial diets as early as possible in the rearing process. ...
... Although other phytoplankton, such as Chaetoceros sp., Isochrysis sp., and Tetraselmis sp., are available food for Artemia, Nannochloropsis contains higher EPA content among these phytoplankton (Liao et al., 2001;Lora-Vilchis et al., 2004;Renaud et al., 1991). The starved Artemia in the present study had a low dry weight and total lipid and EPA contents, indicating a drop in nutrition during starvation, as reported previously (Coutteau and Mourente, 1997;Estévez et al., 1998;Evjemo et al., 2001;Han et al., 2001). NH Artemia also contained lower EPA levels, similar to starved Artemia, and a continuous supply of NH Artemia resulted in low survival during the MG to C1 period in experiment 2. Takeuchi et al. (1999b) reared P. trituberculatus larvae after Z3 with Artemia enriched with various levels of EPA and DHA and reported that EPA improves survival during MG. ...
Survival of the swimming crab, Portunus trituberculatus, during the post-larval period from the megalopal to the first crab stage was low compared with successive larval stages in seed production trials conducted in Japan. To clarify the cause for the low survival, we explored whether rotifers, Artemia, or phytoplankton have negative effects during this period. The effects of the causative factor on larval survival and morphology were verified, and measures to overcome low survival were investigated. We conducted three experiments. In experiment 1, larvae were reared with different types of food (rotifers or newly hatched Artemia) with or without Nannochloropsis oculata supplementation during the late zoeal period (from the third to fourth zoeal stages). After moulting to megalopae, all larvae were fed newly hatched Artemia. The somatic sizes of the last stage (fourth stage) zoeae and megalopae were large, and developmental velocity was faster in the Artemia-fed groups than that in the rotifer-fed groups. However, Artemia feeding induced unviable and morphologically abnormal first-stage crabs with close-set eyes, regardless of Nannochloropsis supplementation. In experiment 2, third stage zoeae were reared to first stage crabs with variously treated Artemia such as newly hatched, 48 h starved, and Artemia enriched with commercially available digestible Nannochloropsis with physically broken cell walls to confirm the negative effects of feeding Artemia. Larvae reared with the newly hatched and starved Artemia containing lower eicosapentaenoic acid (EPA) content exhibited low survival (1.9-3.5%) from the megalopal to the first crab stage, whereas larvae reared with Artemia enriched with digestible Nannochloropsis containing higher EPA content achieved higher survival (40.7%). In experiment 3, newly hatched Artemia were cultured under various conditions such as supplementation with untreated Nannochloropsis, digestible Nannochloropsis, or without phytoplankton to investigate what caused the Artemia to starve. The treatments supplemented with untreated Nannochloropsis and without phytoplankton suppressed Artemia growth and resulted in total mortality 4 days after hatch. Supplementing with digestible Nannochloropsis maintained Artemia growth and resulted in higher survival, suggesting that early Artemia nauplii could not digest Nannochloropsis, which resulted in starvation. Our results indicate that Artemia starve in larval rearing water regardless of supplementation with Nannochloropsis; however, Nannochloropsis are usually added to seed production tanks. Artemia starvation during the late zoeal period exerted a negative carry-over effect during the post-larval period. We recommend nutritionally enriching Artemia with EPA and supplementing larval rearing water with digestible Nannochloropsis during the late zoeal stage.
... Similarly, Hawkyard (2010) found that Artemia enriched with wax spray beads containing iodine and yttrium retained approximately 75% of enriched substances after 8 h of storage; however, the retention rates were not affected by water temperature. Evjemo et al. (2001) found an inverse relationship between water temperature and the depletion rates of total lipids, protein and fatty acids of A. franciscana nauplii during starvation. In the current study, we did not compare the retention of taurine by taurine-enriched Artemia stored at different water temperatures. ...
Taurine is an essential or conditionally essential nutrient for many species of marine fish, especially during early development. There is growing evidence that marine fish larvae benefit from taurine-enriched rotifers; however, it is unknown if larvae benefit from taurine-enriched Artemia. We investigated the effects of taurine-enriched rotifers (Brachionus plicatilis) and Artemia franciscana on the growth and whole-body taurine concentrations of California yellowtail (Seriola lalandi; CYT) larvae. The approach used in this study was to encapsulate taurine within microparticles (liposomes), which were then fed to rotifers and Artemia. We found that feeding taurine liposomes to rotifers and Artemia resulted in taurine concentrations in these prey species that were similar to or above those previously reported in copepods. At the end of the rotifer phase, CYT larvae fed taurine-enriched rotifers showed increased growth (final dry weights; DW) and had higher whole body taurine concentrations when compared to larvae fed unenriched rotifers. At the end of the Artemia phase, CYT whole body taurine concentrations varied among dietary treatments. Larval lengths and DWs were not significantly different among treatments at the end of the Artemia phase, suggesting that the taurine concentrations of unenriched Artemia were sufficient to support the growth of CYT larvae.
... Develop ment was delayed by approximately 3 d at 100 atm and 6 d at 200 atm, relative to ex pected de velopmental rates at 1 atm (Smith et al. 2013) (Fig. 2). Analysis of the DW and elemental (C and N) com position of veliger larvae from each treatment allowed us to determine the remaining energy available to the larvae in each pressure treatment and infer the metabolic cost the larvae had incurred (Anger 2001, Evjemo et al. 2001, Anger et al. 2002, García-Guerrero et al. 2003, Lovrich et al. 2003, Smith et al. 2013. At 1 and 100 atm, pressure did not affect veliger DW, C biomass, N biomass or C:N ratio (Fig. 3, Table 3). ...
Hydrostatic pressure is the most constant physical parameter on Earth. It increases linearly with water depth and is stable over evolutionary timescales. Despite this, bathymetric shifts in physiological adaptations that are observed in marine invertebrates (e.g. in metabolic rate and egg size) are currently interpreted to result predominantly from decreases in temperature. However, analyses of invertebrate egg size data presented here indicate an increase in egg volume with depth in the absence of a thermal gradient. This suggests hydrostatic pressure may also be important in determining resource allocation to offspring. To test the hypothesis that an increase in energy expenditure during development occurs with increasing hydrostatic pressure, we examined the effects of sustained exposure to pressure (1, 100, 200 and 300 atm) on development of a shallow-water marine gastropod, Buccinum undatum. Embryos developed successfully at 1, 100 and 200 atm, but the rate of development slowed with increasing pressure (by 3 d at 100 atm and 6 d at 200 atm). No development was observed at 300 atm. In embryos reared at 200 atm, veliger dry weight and carbon and nitrogen biomass were significantly reduced. These results indicate that high pressure significantly increases the metabolic cost associated with development, demonstrating a negative and ultimately critical effect. We hypothesise that pressure imposes increased metabolic cost on all physiological processes. This offers an additional explanation for physiological adaptations observed with increasing depth, indicating that hydrostatic pressure is an important and previously underestimated factor contributing to metabolic theory for most of our biosphere. Hydrostatic pressure may represent a critical physiological limit for the maximum depth distribution of shallow-water fauna.
... Nevertheless, some disadvantages have been pointed out concerning the use of live foods: (1) the production and use of live foods is expensive (Hart and Purser, 1996); (2) bacteria associated with zooplankton cultures can be detrimental to fish larvae and may act as vectors of diseases; (3) the nutritional values of live foods can be highly variable (Evjemo, et al., 2001 andOlsen, 2004); (4) nutritional quality of live foods is difficult to manipulate (5) metabolites from zooplankton increase the load on fish rearing systems; (6) fine-mesh outlet screens are required to retain zooplankton so low water flow rates are necessary to avoid screen blockages and resultant tank overflows. ...
The present study was carried out in the Marine Fish Laboratory (MFL), Faculty of Agriculture Saba Basha, Alexandria University, Egypt to study the possibility of early weaning of gilthead seabream (Sparus aurata) larvae. Therefore seabream larvae divided into different groups and weaned at 25, 27, 29, 31, 33, 36 and 39 days post hatching (dph). At the end of the experiment the mean wet weight and length of gilthead seabream larvae after 45 dph showed that, the late weaning (33, 36 or 39 dph) significantly increased the wet weight and length of larvae compared to larvae groups that early weaned (25 and 27 dph) and the same trend was also observed for larvae after 60 dph.
Weight gain of gilthead seabream larvae during the period of 45-60 dph ranged between 0.039 to 0.052 gm. The early weaning significantly decreased larvae weight gain (groups 25, 27 and 29 dph) while the late weaning (36 and 39 dph) significantly improved weight gain and the same trend was also observed during the entire experimental period (30-60 dph ).
During the entire experimental period the average larvae specific growth rate found to be 1.39, 1.60, 1.59, 1.54, 1.65, 1.70 and 1.71 for larvae groups weaned at 25, 27, 29, 31, 33, 36 and 39 dph, respectively and the differences between these means were significant.
At 30 dph survival rates for seabream larvae groups found to be 78.67, 86.67, 88.00, 85.33, 88.00 and 88.00. At 60 dph the average survival rates found to be 88.00, 90.33, 89.00, 86.33, 92.00, 99.00 and 89.33% for larvae groups weaned at 25, 27, 29, 33, 36 and 39 dph, respectively and the differences between these averages were significant.
Protein and fat content of gilthead seabream larvae at the end of the experiment ranged between 31.20-36.20 for protein and 2.10 -3.36% for fat, respectively. The obtained results indicated that the late weaning (36 and 39 dph) significantly increased each of protein and fat content of larvae when compared to the early weaning (25 and 27 dph).
... hours (Evjemo et al., 2001)). The amount of Artemia needed was estimated before each feeding, and concentrated in as small a volume as possible. ...
... The catabolized TAGFA represented only a small proportion (# 10%) of the copepod dry wt loss, indicating that fasting Eudiaptomus utilized mostly other body compounds (proteins, carbohydrates) to supply their energetic requirements. Extensive protein catabolism, often after lipid stores have been depleted, has been observed in certain copepods and many other crustacean taxa (Evjemo et al. 2001;Sanchez-Paz et al. 2006;Mayor et al. 2011). Body mass loss was in better agreement with an earlier depletion of energy stores at higher temperature and survivorship. ...
We investigated the effects of temperature (4°C, 8°C, and 12°C) on structural and storage dynamics, as measured by changes in fatty acids (FA) associated with cell membrane phospholipids (PL) and triacylglycerols (TAG), respectively, as well as on body weight and survival of a freshwater calanoid copepod (Eudiaptomus gracilis) during fasting (10 d) and refeeding (10 d) with two algae of differing nutritional quality (Cryptomonas ozolinii and Scenedesmus obliquus). Fasting led to 50% loss in body weight, a near total depletion of TAG, and a drastic decrease of the polyunsaturated FA (PUFA) in TAG and PL, indicating their preferential utilization and alterations in membrane function, respectively. Higher temperatures accelerated the decrease of body weight and of PUFA in PL and TAG, and decreased survival. After 10 d of refeeding, copepods partially recovered their initial lipid stores and cell membrane composition. The effects of food quality were temperature dependent: Cryptomonas promoted better recovery (i.e., return to or close to the levels at the beginning of the experiment) of both body weight and TAG at only the two higher temperatures (8°C and 12°C), whereas no recovery was observed at 4°C. Higher temperatures and refeeding on Cryptomonas also had a positive, but minor, influence on the recovery of membrane FA composition. Survival differed among treatments but was lowest at the intermediate temperature (8°C) for both diets. We conclude that temperature changes on the order of 4–8°C significantly influence TAG and PL during fasting periods and interact with food quality to determine the extent of recovery in copepod lipids.
... Newly hatched Artemia nauplii have commonly been used as a food source in culturing red king crab larvae in the laboratory but survival and development have been variable and generally suboptimal (Kurata 1960, Kittaka et al. 2002, Kovatcheva 2002, Epelbaum and Kovatcheva 2005, Kovatcheva 2006, Persselin 2006). Artemia have little, if any, of the highly unsaturated fatty acids (HUFAs) docosahexaenoic acid (DHA, 22:6n-3) or eicosapentaenoic acid (EPA, 20:5n-3) that are considered crucial for the normal development and survival of crustacean larvae (Levine and Sulkin 1984; McConaugha 1985; Navarro et al. 1991 Navarro et al. , 1993 Anger 2001; Evjemo et al. 2001; Kogane et al. 2007). Interestingly, diets with and without T. nordenskioeldii had similarly high survival until after reaching the Z4 stage, at which point mortality increased in treatments without diatoms (Fig. 1). ...
King crab larval culture has expanded from small-scale research to hatchery and stock enhancement feasibility studies in Alaska. The goal of this project was to improve red king crab (Paralithodes camtschaticus) larval survival in culture by assessing diets and water sources in two separate experiments. Diet treatments included (1) newly hatched Artemia nauplii, and (2) newly hatched Artemia nauplii and the diatom Thalassiosira nordenskioeldii; both treatments were conducted at facilities in Kodiak and Seward, Alaska. The water source study was conducted at the Seward facility and treatments included (1) natural seawater from Resurrection Bay, and (2) artificial seawater made from (Instant Ocean ®) sea salt. At both facilities, mean survival to the glaucothoe stage was significantly higher and mean larval duration was significantly shorter for larvae fed the Artemia-diatom diet. Larval duration and survival to the glaucothoe stage were not significantly different between facilities. In Kodiak, larval survival and duration were carried through to the first juvenile stage (C1); all glaucothoe molted to C1 on the Artemia-diatom diet whereas only two glaucothoe molted to C1 on the Artemia-only diet by the termination of the experiment. In Seward, mean survival to glaucothoe and mean larval duration were not significantly different between larvae reared in artificial seawater and natural seawater. For higher yield
... In contrast, in B. undatum a larger number of smaller offspring are produced under lower temperature conditions, suggesting that in colder years a higher number of less energetically fit offspring will hatch. This resource allocation, although atypical, generally results in offspring receiving a higher level of reserves under warmer conditions, which could compensate for the greater bioenergetic demand necessary for development at higher temperatures, as has previously been reported in this species ) and other marine invertebrates (Evjemo et al. 2001, Garcı´a-Guerrero et al. 2003). This result is further supported by the greater number of offspring observed developing in the B. undatum egg masses from Iceland, where temperatures are naturally lower than in the United Kingdom. ...
Developmental resource partitioning and the consequent offspring size variations are of fundamental importance for marine invertebrates, in both an ecological and evolutionary context. Typically, differences are attributed to maternal investment and the environmental factors determining this; additional variables, such as environmental factors affecting development, are rarely discussed. During intracapsular development, for example, sibling conflict has the potential to affect resource partitioning. Here, we investigate encapsulated development in the marine gastropod Buccinum undatum. We examine the effects of maternal investment and temperature on intracapsular resource partitioning in this species. Reproductive output was positively influenced by maternal investment, but additionally, temperature and sibling conflict significantly affected offspring size, number, and quality during development. Increased temperature led to reduced offspring number, and a combination of high sibling competition and asynchronous early development resulted in a common occurrence of "empty" embryos, which received no nutrition at all. The proportion of empty embryos increased with both temperature and capsule size. Additionally, a novel example ofa risk in sibling conflict was observed; embryos cannibalized by others during early development ingested nurse eggs from inside the consumer, killing it in a "Trojan horse" scenario. Our results highlight the complexity surrounding offspring fitness. Encapsulation should be considered as significant in determining maternal output. Considering predicted increases in ocean temperatures, this may impact offspring quality and consequently species distribution and abundance.
... In support of this assumption, Artemia nauplii treated with lactobacilli at 0-24 th h regimen were presented with negative correlation between free amino acid and protein amount, on one side, and unsaturated lipids, on the other side. This reflects parallel use of both proteins/free amino acids and fatty acids as energetic sources by starved Artemia nauplii, as demonstrated previously (Evjemo et al., 2000). Although, according to this interpretation, lipid reserves of 0-24 th h treated Artemia nauplii were lowered during hatching, no overall decrease of neutral lipid amount in comparison to control was observed with none of 500 g/kg combinations. ...
Bread crumbs are obtained by grinding dried bread. Since bread crumbs can get contaminated from different sources, the aim of the work was to recognize the microbiological and sensory (colour) quality of bread crumbs, as well as the possibility of sterilization applying ionizing radiation. The minimal dosis of gamma rays, efficient for achieving of certain quality and could prolong the shelf-life of this product wad defined.
The investigation results showed that the dosis amounting 5 kGy was efficient for the achieving of suitable microbiological quality of product followed by insignificant change of sensory characteristics, colour in the first place as one of the most important quality characteristics. The colour of crumbs samples was determined instrumentally as well, using the photoelectrical tristimulus colorimeter, MOM color D.
... This allows all juveniles to be at the same relative bioenergetic predisposition at hatching, regardless of temperature. Similar findings have previously been reported for the crustaceans Artemia salina over a four-day period ( Evjemo et al., 2001) and Cherax quadricarinatus over a 20 to 37-day period ( García-Guerrero et al., 2003). In both these studies bioenergetics continued to differ with temperature, regardless of developmental stage, demonstrating high plasticity in these species with embryos rapidly adapting to ambient temperatures. ...
... Another strategy to preserve DHA-rich enrichment diets from oxidation involves an adequate dosage along the enrichment protocol. While one single dose at the beginning of the enrichment process appears to be the most extended dosage mode (Est evez et al. 1999;Villalta et al. 2005a,b), two doses, one at the beginning of the enrichment process and another one at mid-period (Evjemo et al. 1997;Est evez et al. 1998;Han et al. 2000Han et al. , 2001Evjemo, Danielsen & Olsen 2001;Sui et al. 2007;Hamre & Harboe 2008) might contribute to reduce lipid peroxidation as the time of exposure to pro-oxidant conditions (continuous light, high temperature and limited DO) is minimized. The results from this study confirmed that no differences in HUFA bioencapsulation existed when M70 was dispensed in one or two doses, and thus the oxidative stability of M70 enables this enrichment diet to be dispensed in a unique dose without any evident detrimental effect in terms of HUFA incorporation over 21 h of incubation. ...
This study aimed to investigate practical strategies to optimize the use of a high docosahexaenoic acid (DHA) lipid emulsion (M70), a product with great potential in live prey enrichments for marine larviculture. Considering its particularly high content in DHA (22:6n-3), the adequate utilization of the emulsion for Artemia enrichments was evaluated in a series of six experiments. More specifically, the bioencapsulation efficiency of M70 into Artemia nauplii was tested under different experimental conditions of oxygen source, aeration flow, incubation temperature, concentration and dosage, as well as nauplial densities. Our results showed that an optimal utilization of M70 is achieved with incubation temperatures of 28°C, moderate aeration flows and nauplial densities of 300 ind per mL. In addition, the emulsion can be dispensed in the enrichment medium in one single dose of 0.8 g L-1, with no apparent detrimental effects on its oxidative stability and Artemia nauplii survival during enrichment.
... At present, rotifer and brine shrimp are widely used to rear ¢sh larvae and juveniles all around the world because they can be easily cultured in large quantities. However, rotifer and brine shrimp have limited abilities to convert the shorter chain n-3 polyunsaturated fatty acid into docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) (Lubzens, Marko & Tietz 1985;Evjemo & Olsen 1997;Evjemo, Danielsen & Olsen 2000), and are naturally de¢cient in n-3 highly unsaturated fatty acid (HUFA). Therefore, they are potentially insu⁄cient as live prey for the larvae and juveniles of carnivorous marine ¢sh, which require higher amounts of HUFA in the prey (Koven, Tandler, Kissil, Sklan, Friezlander & Harel1990;Rainuzzo, Reitan & Olsen 1994;Evjemo, Reitan & Olsen 2003). ...
Copepods are candidates with great potential as live prey for rearing fish larvae and juveniles in aquaculture; however, the techniques for a large-scale culture of copepods are yet to be developed. In this study, we examined the effects of water temperature, salinity, prey concentration and algal species on the grazing and egg production rates of a calanoid copepod Schmackeria poplesia (Copepoda: Calanoida). The results showed that the grazing rate of S. poplesia was the highest when the copepods were cultured in seawater with temperature of 25 °C, salinity of 20 g L−1, prey concentration at 105 cells mL−1 and supplied with Platymonas helgolandica as the prey. The egg production rates, however, was the highest when copepods were fed with a mixed prey of Isochrysis galbana and Phaeodactylum tricornutum (cell ratio 1:1, prey concentration 105 cells mL−1) at 25 °C, 20 g L−1 of salinity. A 100 L cultural system was established to culture S. poplesia under the condition optimized for egg production. The total number of copepods increased 40–43-fold with the production rates of 87–290 copepods L−1 day−1 in 14 days. This research was the first attempt for a large-scale culture of S. poplesia and the technique established can be further applied in aquaculture.
... Generally, the most appropriate enrichment technique for newly hatched Artemia is commonly applied for a 24-h period after hatching (Han, Geurden & Sorgeloos 2000;Makridis et al. 2000;Sorgeloos, Dhert & Candreva 2001;Stewart, Spicer, Inskeep & Dailey 2001;Woods 2003;Ando, Samoto & Murayama 2004). In our study, the encapsulation time of 48 h was longer than that in other studies conducted by Moren, Gundersen and Hamre (2005), Evjemo, Danielsen and Olsen (2001), Han et al. (2000) and Ritar et al. (2004). Artemia enrichment periods vary with di¡erent enrichment probiotics (Gatesoupe 1991). ...
Abstract The encapsulation capacity of Artemia nauplii with customized probiotics Pseudomonas synxantha and Pseudomonas aeruginosa for use in the cultivation of western king prawns (Penaeus latisulcatus) was investigated. Seven trials were conducted to investigate this encapsulation capacity in terms of Artemia survival and probiotic load in Artemia. Newly hatched Artemia nauplii at 250 nauplii mL−1 were fed individual probiotics at 0, 103, 105 and 107 colony-forming units (CFU) per millilitre, and mixtures of these two probiotics (105 CFU mL−1) at 30:70, 50:50 or 70:30 v/v in a medium of ozonated water (OW), tryptone soya broth (TSB), and a mixture of these media. The appropriate medium for encapsulation of probiotics by Artemia nauplii was the mixture of OW and TSB at 75:25 v/v; whereas, the use of OW or TSB alone was not effective. Artemia nauplii most effectively encapsulated the customized probiotics at 105 CFU mL−1. The results indicates that the encapsulation of Artemia nauplii is optimized by using a combination of P. synxantha and P. aeruginosa at 50:50 v/v in a media mixture of OW and TSB at 75: 25 v/v. Artemia should be harvested at 48 h when survival is still high (78%) and the probiotic load in Artemia is high (3 × 104 CFU nauplius−1).
... An exception is Evjemo and Olsen (1997), who found 15e20% DHA in Artemia enriched with Super SelcoÔ and DHA-SelcoÔ. Many strains of Artemia contain EPA, and the catabolism of EPA in Artemia is lower than that of DHA (Evjemo et al., 2001). ARA (arachidonic acid, 20:4n-6) is found in unenriched Artemia nauplii and can be quite high in enriched Artemia, even though the enrichment medium contains little ARA (Hamre et al., 2002). ...
Over the past few years, great progress has been made in culturing cod larvae in indoor hatcheries using rotifers and Artemia or formulated feed as start-feed (intensive systems). However, when compared with natural systems based on copepods grown in seawater lagoons, the growth potential has not been fulfilled, and deformities of larvae and juveniles increase production costs. The deformities, which are seldom seen in natural systems, also constitute an ethical problem. The differences in growth and development of deformities in intensive and natural systems may be dependent, in part, on nutrition, but are caused by environmental conditions and early husbandry practises as well. To identify nutrients that may be deficient or in excess in live feed, we are in the process of screening the nutrient compositions of rotifers and Artemia grown or enriched on different feeds and comparing them with the composition of copepods and published requirements for larger fish. Replacing live food with formulated diets as early as possible is a goal of marine larval aquaculture. It is important that these diets contain protein which is available for the larvae and phospholipids that promote the absorption and transport of fat. The optimum macronutrient composition in diets for cod juveniles has been determined and can be extrapolated, with caution. to the larval stage. A problem in using formulated diets is the extensive leakage of nutrients as a result of the large surface area to volume and the short diffusion distance in the microparticles. Leakage leads to rapid loss of small, water-soluble molecules such as free amino acids, vitamins, and minerals, but extensive leakage of water-soluble protein has also been shown. The demand for protein available to the larvae, which probably will make the protein more water soluble, is therefore in conflict with the need to reduce protein leakage from the feeds. Development of feed production technology to prevent nutrient leakage is essential in order to make formulated diets a good alternative to live feed. (c) 2005 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.
... At 12°C, however, proteolysis was detected after 200 min and reached a maximum of total FAAs some time after 240 min (Fig. 2). This observation is supported by a report of increased depletion of protein and lipid with increasing temperatures in enriched A. franciscana nauplii during subsequent starvation (Evjemo et al., 2001). Our data revealed a significant effect of temperature on levels of total FAAs (df =4, Fvalue =17.17, ...
Post mortem proteolysis of Artemia franciscana in terms of free amino acid (FAA) concentrations was determined at several temperatures to indicate potential nutritive value. The experiment was conducted for 400 min at 12, 16, 20, 24 and 28 °C to correspond to gut passage times and temperatures expected in the gut of cold-water fish larvae through tropical fish larvae. After death, FAA concentration in A. franciscana nauplii reached a maximum about 2–2.5-fold higher than the initial concentration after 120 min at 16, 20, 24 and 28 °C. At 12 °C the maximum concentration of FAAs was achieved after 240 min. A significant effect of temperature on total FAAs (df=4, F-value=17.17, P
... Rotifers and A. salina nauplii have been widely used as live prey for newly hatched larvae, but they do not always promote optimal growth (Sun & Fleeger 1995). Problems related to the use of these food items include nutritional de¢ciencies and inappropriate sizes (Kahan 1981;Leger, Bengston, Simpson & Sorgeloos1986;Evjemo, Danielsen & Olsen 2001;Holt 2003;Olivotto, Capriotti et al. 2008) and thus alternative food sources that bypass these inadequacies and promote adequate growth are needed and are viewed with great interest by the scienti¢c community (Sun & Fleeger 1995). ...
Rotifers and Artemia salina nauplii are the most widely used live prey for newly hatched larvae, but they do not always promote optimal survival and growth. Alternative food sources such as copepods, which bypass these inadequacies and promote adequate growth, are needed and they are viewed with considerable interest by the scientific community. The aim of the present study was to test two different diets [rotifers and A. salina nauplii (group A) and a mixture (group B) of rotifers/Tisbe spp. copepods and A. salina nauplii/copepods] during the larval rearing of the striped blenny Meiacanthus grammistes. The analysis of the survival rate, size (total length and wet weight) and metamorphosis time during the larval phase of this species showed that Tisbe spp. administration can significantly improve larval survival and growth and also reduce the metamorphosis time. The results obtained are related to the fatty acid content of the live prey used and are essential in order to improve the captive production of M. grammistes through a closed system and, in turn, to preserve natural stocks.
Changes in temperature and starvation are stressors that can modulate metabolism and fatty acid (FA) composition among zooplankton. However, studies on FA modulation have not been conducted on Antarctic zooplankton. In this study, we aimed to understand the changes in life history parameters and FA profiles associated with starvation at four temperatures (4, 8, 14, and 18 °C) in the Antarctic copepod Tigriopus kingsejongensis. In our results, higher temperatures accelerated the development of T. kingsejongensis and increased total offspring. In addition, the production of reactive oxygen species increased with temperature, reflecting an increase in metabolic rate. FA analysis revealed that starvation and higher temperatures decreased the polyunsaturated fatty acid (PUFA) proportion but increased the saturated fatty acid proportion of T. kingsejongensis. Even though the proportion of other PUFAs decreased, docosahexaenoic acid and docosapentaenoic acid were increased by starvation and higher temperatures. Our data provide a better understanding of FA regulation in Antarctic copepods in response to external stressors.
Improving larval nutrition is a key aspect to enhancing larval survival and shortening the larval cycle of the cleaner shrimp Lysmata amboinensis, the most traded shrimp species in the marine ornamental industry. A 30-day feeding trial was conducted in order to investigate the effect of the different feeding schemes: AT- Enriched Artemia meta-nauplii + Thalassiosira pseudonana; RAT- Enriched rotifers + enriched Artemia + T. pseudonana; CAT- Apocyclops panamensis copepodites + Enriched Artemia + T. pseudonana; STR- under starvation, upon growth, survival, and development of L. amboinensis larvae. Larvae in the CAT and STR treatments survived for over 3 days, however, total mortality occurred before day 6 in both treatments, whereas in RAT, larvae had an average survival (± SD) of 68.3 ± 12.5% by the end of the trial and those in AT showed a survival of 30.0 ± 5.0%. Development rate was also higher in RAT, where 44.3 ± 13.8% of the larvae were able to reach the zoea X stage by the end of the experiment. Among the larvae in AT, 88.5 ± 10.3% of them were at the zoea IX stage and a small percentage of the larvae were still at the zoea VIII stage on day 30. Growth in AT (2.02 ± 0.33 mm) was lower than in RAT (3.50 ± 0.26 mm). These results suggest that a diverse diet based on a combination of rotifers, Artemia and the microalgae T. pseudonana promotes a satisfactory performance of early to intermediate L. amboinensis zoea stages.
In nature, marine organisms often face temporal and spatial patchy food sources and are therefore adapted physiologically and behaviourally to these situations. Tropical open water copepods frequently experience food deprivation, which may constrain their growth. Four distinct size fractions of nauplii of the tropical calanoid copepod Pseudodiaptomus annandalei were tested for their response to food deprivation. A 48-h food deprivation period caused a high mortality of 26–71%, a significant effect on molting and on length increments that were reduced by 27–38% compared to non-starved nauplii. Furthermore, the essential fatty acids, arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were reduced by >65% within the 48 h starvation period, and were most profound for the earliest development stages of nauplii. To examine the effect of starvation on the individual copepod nauplius ability to escape a potential predator, a flow generated hydrodynamic signal was used to stimulate an escape response. Starvation slowed down the average escape velocity of the nauplius by up to 49%, and significantly reduced the initial nauplii development stages ability to escape from the flow-generated suction. Additionally, the initial nauplii stages net to gross displacement ratio (NGDR) were significantly reduced by starvation. Hence, the nauplii response to overcome food deprivation is exhibited by both ‘sit and wait’ while recruiting storage compounds and by minimizing their motile behavior. Since starvation affects the nauplii stages escape performance, it is likely to have a profound effect on their ability to avoid a potential predator.
Diversification of marine species has emerged as a priority in the aquaculture agenda of many countries due to its large industrial potential and as an alternative to overharvested fisheries. Aquaculture diversification entails new challenges during early life stages of candidate species such as survival bottlenecks or body malformations, many of them due to uncoupling between classic diets and early nutritional requirements. Monospecific diets are common in fish aquaculture, e.g. beginning with a rotifer-based diet, followed by a mixed diet of rotifer and artemia nauplii and ending with artemia nauplii and metanauplii until weaning. Despite some success was reported using such protocol in early hake feeding the massive mortality observed as approaching 25 dph makes optimization of early feeding and larval management a current challenge for the domestication of this species. The main goal of this study was to design and test a workflow management system for early feeding of the European hake as a candidate species. The null hypothesis tested was that optimization of rearing settings had no effect on early growth and survival up to 30 dph as compared to classic culture protocols using commercial prey. Absence of prey in 6 dph hake larvae stomachs indicates that their external feeding at 14 °C begins just after that age. Early feeding preference depends on prey size (< 500 μm before 9 dph) as well as on pigmentation and behavior e.g. those with poor escape reactivity such as A. franciscana Nauplii. Significant feeding specialization on wild zooplankton such as P. intermedius and T. longicornis occurred after 9 dph (Chesson selectivity index = 0.11). Feeding activity was maximal in darkness (D) and medium light intensity (600 lx, MLI) as compared to the lethal light intensity of 1700 lx (HLI). Rotifer-based diets entailed low larvae growth and hake culture unviability after 15 dph but inclusion of wild zooplankton in early diets doubled growth of 30 dph larvae regarding artemia-based diets. The adaptive prey-size diet designed (MiACop) by combining stages of copepods (nauplii, copepodite and adult), rotifer and commercial nauplii of artemia was five-fold superior to the artemia/zooplankton diet all along the first 30 dph larvae culture. The massive cannibalism observed from 25 dph on was related to the absence of an adequate prey size such as that of mysids and euphausiids in combination with semi-dry feed to trigger weaning. Current workflow design for early feeding of the European hake can be helpful to assuring a larger proportion of juveniles entering the weaning phase.
The main objective was to study time kinetics of change in important highly unsaturated fatty acids (HUFAs) in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of Artemia franciscana nauplii and juveniles following enrichment and subsequent starvation. Samples of Artemia nauplii were taken at variable times (0.5–24 h) following enrichment and starvation. Samples of Artemia juveniles were taken after 2, 3 and 4 days of cultivation. No docosahexaenoic acid (DHA) was found in PC and PE of Artemia nauplii during the first hour of enrichment, while a significant (P < 0.05) increase was found in total lipids (TLs). The content of DHA in PC and PE increased thereafter steadily from 1 to 8 h of enrichment. DHA in PC and PE during enrichment (1–8 h) and following starvation (8–24 h), respectively, increased and decreased significantly (P < 0.05), but at a lower rate than that in TL. Moreover, juvenile Artemia (2–4 days) contained a relatively low level of DHA in TL compared with enriched Artemia nauplii, but the content of DHA in PC and PE was similar. The results open perspectives for both industry and science. For scientific studies, the lag phase in HUFA enrichment makes it possible to produce Artemia nauplii with variable relative HUFA enrichments in phospholipids and TL.
Intracapsular development is common in marine gastropods. In many
species, embryos develop alongside nurse eggs, which provide nutrition
during ontogeny. The common whelk Buccinum undatum is a commercially
important North Atlantic shallow-water gastropod. Development is
intracapsular in this species, with individuals hatching as crawling
juveniles. While its reproductive cycle has been well documented,
further work is necessary to provide a complete description of
encapsulated development. Here, using B. undatum egg masses from the
south coast of England intracapsular development at 6 °C is
described. Number of eggs, veligers and juveniles per capsule are
compared, and nurse egg partitioning, timing of nurse egg consumption
and intracapsular size differences through development are discussed.
Total development took between 133 and 140 days, over which 7
ontogenetic stages were identified. The number of both eggs and veligers
were significantly related to capsule volume, with approximately 1 % of
eggs developing per capsule. Each early veliger consumed nurse eggs
rapidly over just 3-7 days. Within each capsule, initial development was
asynchronous, but it became synchronous during the veliger stage. No
evidence for cannibalism was found during development, but large size
differences between embryos developing within each capsule were
observed, and occasionally `empty' veligers were seen, which had not
successfully consumed any nurse eggs. These results indicate a high
level of competition for nurse eggs within each capsule during
development in the common whelk. The initial differences observed in
nurse egg uptake may affect individual predisposition in later life.
The encapsulation capacity of Artemia nauplii with customized probiotics Pseudomonas synxantha and Pseudomonas aeruginosa for use in the cultivation of western king prawns (Penaeus latisulcatus) was investigated. Seven trials were conducted to investigate this encapsulation capacity in terms of Artemia survival and probiotic load in Artemia. Newly hatched Artemia nauplii at 250 nauplii mL1 were fed individual probiotics at 0, 103, 105 and 107 colony-forming units (CFU) per millilitre, and mixtures of these two probiotics (105 CFUmL1) at 30:70,50:50 or 70:30 v/v in a medium of ozonated water (OW), tryptone soya broth (TSB), and a mixture of these media. The appropriate medium for encapsulation of probiotics by Artemia nauplii was the mixture of OWand TSB at 75:25 v/v; whereas, the use of OWor TSB alone was not efective. Artemia nauplii most efectively encapsulated the customized probiotics at 105 CFUmL1. The results indicates that the encapsulation of Artemia nauplii is optimized by using a combination of P. synxantha and P. aeruginosa at 50:50 v/v in a media mixture of OW and TSB at 75: 25 v/v. Artemia should be harvested at 48 h when survival is still high (78%) and the probiotic load in Artemia is high (3 104 CFUnauplius1).
IntroductionAchievementsChallengesProspective/future outlookReferences
Grouping organisms may suffer reduced growth due to food deprivation in the presence of larger conspecifics, but this cost can be outweighed by advantages of reduced predation risk in larger groups. Here, tagged new juveniles of a small, grouping damselfish Dascyllus aruanus, were added to small coral heads that were either empty or supported small groups of larger conspecifics. Half of the coral heads with conspecifics and half of those without were subjected daily to additions of brine shrimp, similar to natural zooplankton food, over a three-week period. Growth was measured as increase in body length, change in body condition (lipid content), and overall energy gain. Body lipid reserves were higher (21%) in recruits subjected to added food and in the presence of conspecifics (13%). Total energy was higher (53%) in recruits with added food but was not affected by conspecific presence. There was an interaction between conspecific presence and food supplementation treatment on change in body length, a commonly used growth estimator. These differences suggest that the benefits of extra food and effects of conspecific presence differ depending on the metric used to measure growth, but that presence of larger conspecifics enhanced the increased growth that resulted from higher food intake.
Many fish larvae require live feed to be successfully raised through their early life. The necessity to use live feed is regulated by many aspects during fish larvae ontogeny, but is mainly attributed to the need for a behavioral stimulus to attack particles and for a developed gut to digest them. In this review, we first provide a background on the importance of live feed in fish larviculture. We then present the state of knowledge on live feeds (microalgae, rotifers, Artemia, copepods, and other non-conventional live feeds), their production, and uses. Particularly, we compare the advantages and disadvantages of culture methods, production systems, storage, and enrichment for various live feed species. Considering that enrichment of live prey is often necessary to meet the nutritional needs of fish larvae, we also included a section addressing the various aspects of enrichments. We conclude with future prospects as well as an overview of R & D needs that may improve the use of live feeds while decreasing their production costs.
Atlantic halibut larvae were fed Artemia enriched with two different oil emulsions (cod liver oil and 2050TG) from first feeding to 70 days after first-feeding (dpff). Larvae fed 2050TG enriched Artemia had better growth, survival and eye migration than larvae fed the cod liver oil enriched Artemia, while pigmentation rate was similar in the two groups. In addition to the difference in fatty acids, the two emulsions differed in lipid class composition, since 2050TG is a synthetic oil and a mixture of mono-, di- and tri-acylglycerol, while cod liver oil is a tri-acylglycerol. Total lipid level, estimated as fatty acid methyl esters (FAME) was similar in the two Artemia types, but sum of n-6 and n-3 fatty acids, arachidonic acid (20:4n-6, ARA), docosahexaenoic acid (22:6n-3, DHA) and eicosapentaenoic acid (20:5n-3, EPA) were higher in Artemia enriched with 2050TG than in the cod liver oil enriched Artemia. However, the main difference in fatty acid composition in the larvae, was a higher DHA (% of total fatty acids) in 2050TG larvae than in cod liver oil larvae. The lipid level measured as FAME was up to four times higher in the 2050TG larvae than in the cod liver oil larvae, and the reason for this may have been a better bioavailability of the partly digested lipid in the 2050TG emulsion. The correlation between a high level of lipid in the larval tissues (e.g. high energy status) and improved eye migration in larvae fed the 2050TG enriched Artemia supports the hypothesis that energy limitation on the larval stage may be a cause of the impaired eye migration commonly observed in farmed Atlantic halibut juveniles.
Survival, growth (length and weight), development, proximate composition, and energy content of Artemia franciscana fed for 7 days with Isochrysis sp. (TISO) or with Chaetoceros muelleri (CHGRA) were compared to evaluate the food value of these microalgae. Mean daily survival was not significantly different, and ranged from 86% to 93%. Diet-related differences in growth were noted from the third day, and mean final dry weights (DWs) were 171 and 327 μg ind−1 for Artemia fed TISO and CHGRA respectively. Rates of development were different between diets, with a higher developmental index for Artemia fed TISO before day 3, and a higher index for Artemia fed CHGRA for the rest of the experiment. Chemical analysis showed that carbohydrates decreased to approximately 35% of the initial value in Artemia during the first 24 h, after which they remained approximately stable and similar with both diets. In percentage of total DW, lipids and proteins remained close to their respective initial values, but A. franciscana fed TISO had a higher ash content. A major difference between the two microalgae was the higher protein content of TISO, but this did not result in better growth. Of the two, TISO was richer in docosahexaenoic acid, which might explain the initial faster development, but CHGRA was a better source of eicosapentaenoic acid, which is the most probable explanation of the higher food conversion index, specific growth rate, and energy gain of A. franciscana fed this algae.
IntroductionBiology of ArtemiaProduction Methods: Tank Production of ArtemiaBiomass3.4. Biochemical compositionApplications of Artemia
Artemia nauplii enriched for 18 h using six emulsions with widely differing essential fatty
acids levels were subjected to starvation for 24 h at 4, 12, and 208C. Fatty acid profiles were
monitored after 12 and 24 h at these temperatures and analysed by a two-way analysis of variance
�ANOVA. to investigate the effects of temperature, time and the interactions of both factors on the
fatty acid changes observed in the disenriched nauplii. Docosahexaenoic acid �DHA. levels
decreased to less than half their initial value after 24 h starvation. Eicosapentaenoic acid �EPA.
and arachidonic acid �AA. were also catabolized, although in a lower rate than DHA, after 24 h.
�ny3.r�ny6. ratios remained relatively unchanged. Starvation period was the factor that
affected the fatty acid profile to a greater extent than the temperature used, although the loss in
essential fatty acid was generally more rapid at higher temperatures. The adjustment of daily
ration and feeding frequency of enriched Artemia nauplii to meet larval requirements is
recommended in order to prevent disenriched live-prey in the rearing tank
The effect of three different rotifer enrichments was examined on growth, survival, pigmentation and viability of first feeding turbot larvae. The diets differed in rotifer content of protein, lipid and ratio of protein/lipid. The diets were fed to turbot with or without algae (Isochrysis galbana) added to the larval tanks. The turbot larvae were fed rotifers for 10 days and thereafter the same Artemia diet was fed to all treatments for the rest of the experimental period. Growth and survival of fish larvae were higher in tanks containing algae than in tanks where no algae were added. Independent of algal addition, the highest growth rate and survival was obtained by feeding rotifers containing the highest protein content. Larvae reared in greenwater consumed higher numbers of rotifers during the stagnant period than larvae kept in clearwater conditions, while analysis of the larval gut contents showed lower rotifer numbers in the gut of larvae reared in greenwater conditions. This must imply longer residence time of the food in the larval gut, and presumably also higher digestion and assimilation efficiencies of larvae maintained without algae than in larvae maintained with algae. Calculation of protein and carbon conversion efficiency showed higher utilization in larvae maintained without algae (18-28% for protein, 12-19% for carbon) than in larvae maintained with algae (6-9% for protein, 4-7% for carbon). No significant differences in pigmentation rata and stress sensitivity were observed among the larvae of the various treatments.
The effect of different lipid compositions of live feed on the survival, growth rate and pigmentation success of turbot larvae, Scophthalmus maximus (L.), was investigated. Rotifers, Brachionus plicatilis, together with the algae Tetraselmis sp., were administered until day 12, and Artemia was fed until day 27. The experimentally treated live feeds were enriched with four formulated emulsions, resulting in a gradient in the relative contents of Ω3 HUFA (highly unsaturated fatty acids) and in DHA (docosahexaenoic acid, 22:6 Ω3)/EPA (eicosapentaenoic acid, 20:5 Ω3) ratios in both the rotifers and Artemia.
There were no differences in larval growth rate, and only small differences in survival rate throughout the feeding experiment, probably because of satisfactory levels of Ω3 HUFA in the live feed to sustain growth and survival. A correlation was obtained between the percentage of completely pigmented 27 d old turbot and the DHA/EPA ratio in the total lipids of 12 d old larvae, which again was correlated with the corresponding ratio in the live feed used. The results suggest that normal pigmentation in turbot requires dietary DHA in the early larval feeding period, and that this requirement cannot be replaced by EPA.
Rotifer cultures of Brachionus plicatilis (SINTEF-strain, length 250 μm) rich in ω3 fatty acids were starved for > 5 days at variable temperature (0–18 °C). The net specific loss rate of rotifer numbers were 0.04 day−1 (range 0–0.08 day−1) at 5–18 °C, but reached values up to 0.25 day−1 at 0–3 °C. The loss rate was independent on culture density (range 40–1000 ind ml−1), but was to some extent dependent on the initial physiological state of the rotifers (i.e., egg ratio).
The loss rate of lipids was 0.02–0.05 day−1 below 10 °C, where the potential growth rate of the rotifer is low (0–0.09 day−1). The loss rate of lipids increased rapidly for higher temperatures where the rotifer can maintain positive growth, and reached 0.19 day−1 at 18 °C. The Q10 for the lipid loss rate versus temperature was higher than the Q10 for respiration found in other strains. This may suggest that other processes than respiration were involved in lipid catabolism. The content of ω3 fatty acids became reduced somewhat faster than the lipids (i.e. in particular 22:6 ω3), but the fatty acid per cent distribution remained remarkably unaffected by the temperature during starvation.
The results showed that rotifer cultures could be starved for up to 4 days at 5–8 °C without essential quantitative losses of lipids, ω3 fatty acids, and rotifers. The rotifers exhausted their endogenous lipids through reproduction (anabolism) and respiration (including enhanced locomotion) at higher temperatures. At lower temperatures, the mortality rate became very high.
The rotifer Brachionus plicatilis (O.F. Muller) can be mass cultivated in large quantities and is an important live feed in aquaculture. This rotifer is commonly offered to larvae during the first 7–30 days of exogenous feeding. Variation in prey density affects larval fish feeding rates, rations, activity, evacuation time, growth rates and growth efficiencies. B. plicatilis can be supplied at the food concentrations required for meeting larval metabolic demands and yielding high survival rates. Live food may enhance the digestive processes of larval predators. A large range of genetically distinct B. plicatilis strains with a wide range of body size permit larval rearing of many fish species. Larvae are first fed on a small strain of rotifers, and as larvae increase in size, a larger strain of rotifers is introduced. Rotifers are regarded as living food capsules for transferring nutrients to fish larvae. These nutrients include highly unsaturated fatty acids (mainly 20: 5 n–3 and 22: 6 n–3) essential for survival of marine fish larvae. In addition, rotifers treated with antibiotics may promote higher survival rates. The possibility of preserving live rotifers at low temperatures or through their resting eggs has been investigated.
During the cultivation of marine fish larvae, unconsumed rotifers (Brachionus plicatilis) may reside in the tanks for several days and their nutritional value may become severely reduced. In order to quantify this process, body biomass and protein content per individual rotifer was measured during starvation at different temperatures (4–28°C) for a period of 5 to 7 days. Both well-fed rotifers and poorly-fed rotifers were used, in order to examine the effect of the nutritional status at the start of the experiment on the loss rates of biomass and protein. At high temperatures the carbon, nitrogen and amino acid content decreased exponentially with time. A large part of body biomass (40–50%) was lost during the first 4 days of starvation at 18–20°C. The rate of decrease was positively related to the temperature. Poorly-fed rotifers were more sensitive to starvation than well-fed rotifers, as their nitrogen content decreased at a higher rate. Starvation of rotifers may be prevented by addition of microalgae in concentrations of 1–2 mg C l−1. At 4–5°C, the carbon, nitrogen and amino acid content remained relatively stable. Rotifers may thus be stored for <5 days at 4–5°C without a significant loss in their nutritional value.
Artemia eggs and nauplii from different locations were analysed for fatty acids in order to clarify their food value to fish. The results demonstrated that Artemia could be classified into two types by the fatty acid composition; one contained a high amount of 18:3ω3, which is the essential fatty acid (EFA) for freshwater fish, and the other was high in the content of 20:5ω3, which is one of the EFA (together with 22:6ω3) for marine fish. Artemia from San Francisco in 1975 and 1976 and from South America in 1977 were found to be high in the content of 18:3ω3 and quite low in the content of the EFA for marine fish, suggesting a poor food value to marine fish. On the other hand, the concentration of 20:5ω3 was high in Artemia from San Francisco and Canada in 1977, and they were found to be satisfactory as a living feed for red sea bream juveniles. The dietary value of Artemia nauplii was improved by feeding them marine Chlorella and yeast supplemented with cuttlefish liver oil, both containing high amounts of the EFA of marine fish. The starvation of newly hatched Artemia nauplii containing a high amount of 18:3ω3 showed that the lipid and 18:3ω3 contents significantly decreased and the level of 20:5ω3 increased. This may suggest the conversion of 18:3ω3 in Artemia nauplii, to 20:5ω3, to some extent, but not to 22:6ω3. Thus the present study has demonstrated that the class of EFA contained in Artemia is the principal factor in the food value of Artemia to fish.
Feeding experiments were conducted to determine the requirements of early juvenile red sea bream (Pagrus major) for eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) by feeding Artemia nauplii containing different levels of EPA or DHA for 12 days. Juveniles fed EPA-enriched Artemia had a high survival rate but very poor vitality, while those fed on Artemia enriched with DHA had both a high survival rate and vitality. The vitality of fish was effectively improved by elevation of DHA levels in Artemia. In the DHA-enriched Artemia, the EPA content increased from the initial value together with the appearance of docosapentaenoic acid (DPA), indicating retroconversion from DHA to EPA through DPA in the nauplii. The requirement of early juvenile red sea bream for DHA was estimated to be 0.95-1.62% in Artemia on a dry matter basis when vitality was used as an index, and was satisfied with 2.25% EPA or 0.95% DHA (2.05% n-3 HUFA) on a dry basis when based on the survival rate.
Linolenic acid and/or ω3 polyunsaturated fatty acids (a mixture of 20:5 ω3 and 22:6 ω3) were incorporated at levels of 1% and 2%, respectively, into a corn oil control diet, and fed to red sea bream fingerlings. After a 45-day feeding period, it was found that the linolenic acid supplement did not improve the growth rate, whereas the ω3 polyunsaturated fatty acid sup-plement resulted in a marked improvement in the growth rate and feed efficiency. It is to be noted that highest growth rate and feed efficiency were seen in those fish fed a pollack residual oil which contained only trace amount of linolenic acid.
There are large variations in the measured essential amino acid requirements of different species of fish when expressed as a proportion of the diet. The question of whether or not these are real differences is considered. Dietary amino acids are needed for growth and for maintenance, and the former is quantitatively much the more important in young, rapidly growing fish. It is noted that the amino acids laid down during growth are sensibly the same in different species. Maintenance is considered to consist of losses from the integument and intestine, from oxidation of amino acids, from conversion of amino acids to other N-molecules and from protein turnover. Losses from these causes are considered and are not thought likely to differ appreciably between species. When amino acid requirements are expressed as a proportion of the dietary protein, differences, while reduced somewhat, are still wide. The dilemma is illustrated by reference to the differences in amino acid requirement values for rainbow trout from different laboratories. Factors likely to affect the overall performance of fish in requirement studies (water quality, different sources of amino acids and so on) are enumerated, but are not thought likely to explain the observed discrepancies. Dietary energy density is an important factor affecting amino acid requirement, but there are uncertainties surrounding metabolisable energy contents of major dietary components and this tends to preclude expression of amino acid requirement in terms of metabolisable energy. Other methods of assessing amino acid requirement are regarded as subsidiary to, and confirmatory of, growth data. Where amino acid deficiencies lead to tissue pathologies it is important that the stated requirement level is such as to prevent such pathologies. A table of requirement values for channel catfish and trout is provided; it is based on all published values but with greater weight being given to studies characterised by high rates of growth. The relative proportions of essential amino acids in the requirement pattern of the two species bear a strong similarity.
In Artemia franciscana, enriched for 24 h with emulsified lipids, thefatty acid DHA (22:6?3) is unstable. In rotifers the level of DHA canbe stabilised by adding algae rich in DHA to the fish tanks. To test thismethod for A. franciscana, enriched A. franciscana was incubated with thealga Isochrysis galbana, which is rich in lipids and DHA, at sixconcentrations ranging from 1 to 20 mg C l-1 at 13–14°C. After lipid enrichment, A. franciscana contained15% lipids of which 79% (116 mg g DW-1) werefatty acids. Of the fatty acids, 17% was DHA (19.8 mg gDW-1). After 72 hours incubation with I. galbana, the level ofDHA decreased to 1.6–3.2 mg g DW-1, which was areduction by 84–92%. This was independent of the algalconcentration. The amount of total fatty acids decreased to 53–73 mg gDW-1, a reduction by 37–54%, independent of thealgal concentration. The rates of loss of the fatty acids, and especiallyDHA, was greater during the first 24 h at the highest algal concentrations(8, 10 and 20 mg C l-1). Enriched A. franciscana shouldtherefore not be incubated with high algal concentrations (>6 mg Cl-1) during first feeding of marine fish larvae.
Larvae of Atlantic halibut were offered different combinations of Artemia and wild Zooplankton during first feeding to examine the effects on feeding incidence, growth, survival and pigmentation. Free amino acid and fatty acid composition in feeds and fish larvae were also analysed. The free amino acid concentration in unenriched Artemia averaged 45 μmol/g w.w., compared to 116 μmol/ g w.w. in the wild Zooplankton. Super Selco™ (Artemia Systems, Belgium)-enriched Artemia increased the concentration to 57 μmol/g w.w. on average, and also increased the lipid content in Artemia to approximately the levels found in wild Zooplankton (3.0% of wet weight), though with a much lower n − 3 PUFA content. Larvae fed 19 days on enriched Artemia (EA) were significantly larger than larvae fed wild Zooplankton (Z), wild Zooplankton for 7 days then unenriched Artemia (Z7) or unenriched Artemia (UA). The EA group also showed the best survival at day 19, 28.7% (19.9–34.4%) compared to 14.0% (13.2–14.7%) in the Z group and 13.6% (10.5–18.3%) in the Z7 group. Also the UA group had significantly higher survival 22.8% (18.8–25.5%) than the Z group, but showed slower growth. The fatty acid composition of larvae fed Artemia showed a development towards the composition of their feeds, while the fatty acid composition in the larvae fed wild Zooplankton remained relatively similar to that of prefed larvae. After 57 days of feeding, high frequencies of malpigmented juveniles were observed in the UA and EA groups (95.7 and 70.6%, respectively) as well as in the Z7 group (80.8%). All larvae fed wild Zooplankton or larvae transferred from an unenriched Artemia diet to a diet of wild Zooplankton from day 19 onwards, became normally pigmented. The present experiment showed that use of Artemia could be successful in providing growth and survival in the early larval stage of exogenous feeding in Atlantic halibut, but had negative effects on pigmentation later on. However, by introduction of wild Zooplankton prior to a critical stage (found to be beyond 19 days of feeding) these effects could be eliminated.
1.1. Fatty acid and lipid class composition were determined in larvae of four marine species: Atlantic halibut (Hippoglossus hippoglossus L.), plaice (Pleuronectes platessa), cod (Gadus morhua) and turbot (Scophthalmus maximus) at hatching and prior to first feeding.2.2. Total fatty acid content decreased in the four species with up to 50% reduction in one of the halibut groups. Docosahexanaoic acid (22:6 n-3) was especially utilized.3.3. Low lipid utilization was found in turbot in relation to the other three species.4.4. Water environmental temperature may explain some of the differences in the fatty acid utilization and the source of metabolic energy between cold water species (halibut, cod, and plaice) and temperate species (turbot), in the period from hatching to prior to first feeding.5.5. Relative amounts of neutral lipids and phospholipids were similar in plaice, cod and halibut, approximately 25% and 75% of total lipids, respectively, and were approximately constant during the yolk-sac stage. Neutral lipids were dominant for turbot at hatching, accounting for 53–55% of the total lipids, while phospholipids predominated prior to first feeding, being 56–59%.6.6. Phosphatidylcholine was catabolized in halibut, plaice and cod but not in turbot, while phosphatidylethanolamine tended to be synthesized in all four species.
A docosahexaenoic acid (DHA), 22:6(n-3), rich strain of Schizochytrium sp. was used in a spray-dried form to evaluate the enhancement of highly unsaturated fatty acids (HUFAs) in Artemia franciscana nauplii (Utah biotype) and the rotifer Brachionus plicatilis. This heterotrophic microalga was selected because of its high concentration of the longest chain HUFAs in the n-3 and n-6 series, DHA and docosapentaenoic acid (DPA), 22:5(n-6), respectively. When 24-h-old Artemia nauplii were fed 400 mg/L of the algae for 24 h, the DHA content of the nauplii went from undetectable levels to 0.8% of dry weight and the omega-3 HUFA eicosapentaenoic acid (EPA), 20:5n-3, content went from 0.1% to 0.5% of dry weight in the nauplii. Similarly, 22:5(n-6) increased in the nauplii from undetectable levels to 0.4% of dry weight, with a concomitant increase in arachidonic acid, (20:4n-6), from trace to 0.3% of dry weight even though there was no arachidonic acid in the algal biomass. Similar enrichment patterns were observed in rotifers. The results suggest that spray-dried cells of Schizochytrium sp. are effective in enriching Artemia naupli and rotifers in both n-3 and n-6 HUFAs. The results also suggest that Artemia nauplii and rotifers are capable of readily retroconverting 22:6(n-3) to 20:5(n-3) and 22:5(n-6) to 20:4(n-6) through the process of β-oxidation, a well-known process in mammals.
Atlantic herring larvae (Clupea harengus) were fed two enriched Artemia diets with different contents of (n-3) highly unsaturated fatty acids (HUFA), one containing low levels of 20: 5(n-3) and no 22: 6(n-3), the other containing substantial levels of both 20: 5(n-3) and 22: 6(n-3). After 30 days of culture, fatty acid compositions of lipid classes in the heads, bodies and eyes of the larvae were analysed. Fish fed Artemia with the low (n-3) HUFA diet lacking 22: 6(n-3) had lower amounts of total (n-3)HUFA and, in particular, of 22:6(n-3) in individual phospholipids and total neutral lipids of heads, bodies and eyes as compared to fish fed Artemia with high levels of (n-3)HUFA. The amount of 22: 6(n-3) in the fatty acids of phosphatidyl-ethanolamine of eyes was particularly susceptible to dietary depletion. The implications of these findings are discussed, particularly in relation to dietary requirements for 22: 6(n-3) during development of neural tissue in predatory fish iarvae.
Rotifers (Brachionus plicatilis) grown at different growth rate (µ = 0.05−0.39 d−1) were analyzed for protein, lipid, fatty acids, amino acids and free amino acids, and values are expressed in terms of individuals and dry weight. Increase in growth rate is equivalent with increased food ration of the individual rotifer, which responded by higher egg ratio. The protein content per individual rotifer increased by 60–80% when the growth rate increased, whereas the protein content per dry weight showed a slight, although insignificant, increase (p>0.05). The lipid content per individual was constant, whereas lipid per dry weight decreased when the growth rate increased. The ratio DHA/EPA decreased when the growth rates increased. The amino acids profile in percent of total amino acids showed low variation between cultures maintained at different growth rates, whereas the values expressed in terms of amino acid per individual showed higher variation. The range of variation for free amino acids was more pronounced than for total amino acids.
Short-term food enrichment of poorly fed rotifers (µ = 0.05 d−1) with balanced protein rich diet resulted in increased protein and lipid content per rotifer. The protein content per dry weight showed only minor changes whereas lipid per dry weight increased. Contrary, short term enrichment with a lipid rich diet resulted in increased lipid content per individual rotifer and per dry weight, whereas the protein content per individual remained constant and the protein content per dry weight showed a slight decrease.
Our experiments show that the amount of protein, was quite variable in rotifers, and that feeding and growth condition were decisive factors affecting it. The range of variation was large enough to be an important factor during first feeding of marine larvae, and should therefore be considered in feeding larvae.
This paper describes evidence of (n−3) and particularly of 22∶6 (n−3) fatty acid enrichment in trout lipoproteins as well
as in vitellogenin, egg lipovitellin and oil globule. Among the lipoproteins, HDL and LDL were the main forms of blood lipid
transport, whereas phospholipids and cholesteryl esters are the preferential chemical carriers for (n−3) fatty acid transport.
However, cholesteryl esters were less important as esterified fatty acid carriers than in man. Taken together with the data
obtained in mammals, our results suggest that there may be a relationship between EFA activity and the distribution of the
EFA among the lipoprotein lipid fractions in vertebrates, irrespective of the EFA series. Administration of an (n−3) fatty
acid deficient diet for three months prior to trout spawning produced a significant increase in egg lipid content, primarily
as a result of the increase of the oil globule composed almost exclusively of triacylglycerols. This diet decreased the 22∶6
(n−3), as well as the (n−3) fatty acid contents of lipoproteins, lipovitellin, vitellogenin and the oil globule. In contrast,
the (n−3) fatty acid level was always higher in lipoproteins and lipovitellin than in the vitellogenin and the oil globule.
Moreover, the relative levels of 22∶6 (n−3) and total (n−3) fatty acids were quite similar in lipoproteins and lipovitellin
on the one hand, and in vitellogenin and the oil globule on the other. These findings suggest a direct relationship between
the two forms of plasma lipid transport and the two egg compartments. During ovogenesis, dietary lipids seemed to be diverted
from the adipose tissue and essentially deposited in the egg.
Herbivorous zooplankton species (Calanus plumchrus, Paracalanus parvus and Euphausia pacifica) and carnivorous species (Parathemisto pacifica and Pleurobrachia pileus) collected from Saanich Inlet, British Columbia, Canada, were maintained in the laboratory under fed and starved conditions. Respiration rate and excretion rates of ammonia and inorganic phosphate were measured successively on the same batch populations of each species in different feeding conditions. Respiration rate remained at a constant level or increased during the feeding experiment but decreased progressively in starved individuals. Herbivorous, but not carnivorous, species showed a rapid decrease in both excretion rates for the first few days of an experiment irrespective of feeding conditions. However, the general level of excretion rates of fed specimens was higher than that of starved ones. The O:N, N:P and O:P ratios were calculated from respiration, ammonia excretion and phosphate excretion and discussed in relation to metabolic substrates of animals during the experiment. A marked difference was shown in the O:N ratio between fed hervivores (>16) and fed carnivores (7 to 19), suggesting highly protein-oriented metabolism in the latter. One unknown factor causing variation in excretion rates is speculated to be the physiological stress on animals during sampling from the field. It is suggested that the laboratory measurement of realistic excretion rates of zooplankton is difficult owing to their large fluctuations, but this is not the case with respiration rate.
The total lipid content in Artemia franciscana (21–23% ofdry weight (DW)) when enriched with either Super Selco or DHA Selco wastwice as high as in the adult copepods Temora longicornis and Eurytemora sp.(9–11% of DW). In Brachionus plicatilis the total lipid contentwas 11 and 6.6% for cultures growing at high and low growth rate,0.12 d–1 and 0.38 d–1, respectively. In thecopepodid stages I, II and III of Calanus finmarchicus the total lipid levelwas 12–13%, increasing to 24% in copepodid stage IV, Vand the adults. In T. longicornis and Eurytemora sp. the predominant fattyacids were DHA (22:6n-3), EPA (20:5n-3) and the saturated fatty acid 16:0,which constituted 40–45%, 21–24% and8–12% of total fatty acids, respectively. C. finmarchicuscontained the same dominant fatty acids. In both the cultivated live feedorganisms DHA, EPA and 18:1 were the predominant fatty acids. In A.franciscana the content of these fatty acids varied according to theenrichment medium and in B. plicatilis according to the growth rate.
The effect which microalgal addition and rotifer enrichment with algae had on survival, growth rate and fry viability during first-feeding were examined for turbot (Scophthalmus maximus L.). Addition of the microalgae Isochrysis galbana or Tetraselmis sp. together with rotifers Brachionus plicatilis, grown on yeast and oil emulsion, and Artemia greatly improved rearing success, whereas short-term enrichment of the rotifers with Tetraselmis sp. gave only improved viability. The algae modified the relative fatty acid composition of rotifers. Rotifers with I. galbana exhibited and increased level of 22:6n-3 and a lower level of 20:5n-3, whereas the opposite change occurred when Tetraselmis sp. was used. Addition of either of the two algal species at 1 mg cl−1 to the larval tanks resulted in a constant lipid level and high egg ratio of the rotifers, and thereby also high individual biomass content. Without algal addition, the lipid content of the rotifers decreased by 20% day−1 in the early phase, and their egg ratio became close to zero. In addition to improved nutritional conditions of the larvae, some other factor, e.g. some trigger mechanism or changed microbial or light conditions, also can operate to explain the increased early appetite of larvae with microalgae added and must be taken into consideration.
The mass production of zooplankton, in particular the rotifer, Brachionus plicatilis, and the brine shrimp, Artemia salina, is considered to be of vital importance for the rearing of larval fish (up to 30–50 mm total body length) in Japan. Data on the proximal, mineral, protein and essential fatty acid (EFA) contents of live food organisms are reviewed: the EFA content chiefly determines the dietary value for fish larvae. The EFA content of rotifers supplied with yeast during the culture period was less favourable for larval fish growth than that of rotifers given marine Chlorella. The nutritional value of yeast-fed rotifers may be improved either by the use of the recently developed ω-yeast (indirect method) or by feeding with a mixture of homogenized lipids and baker's yeast (direct method). Artemia could be classified into two types, marine — containing a high content of 20:5ω3 (an EFA for marine fish), and freshwater — containing a high content of 18:3ω3 (an EFA for freshwater fish). The fish mortalities sometimes encountered with Artemia may be related to this difference. Either type may be used for freshwater fish larval nutrition. For marine fish, the marine Artemia type is adequate but the freshwater type should be fed together with marine copepods or should be enriched by feeding on lipids with high ω3 HUFA contents.
Artemia nauplii were enriched for 24 h with radiolabelled fatty acid ethyl esters and then starved for a subsequent period of 24 h. Analyses of the distribution of radioactivity in lipids from samples taken at the end of the enrichment period and after the subsequent starvation showed that the ethyl esters were readily converted into other lipid classes, mainly triacylglycerols, during assimilation by the nauplii. The proportions of radioactivity recovered in free fatty acids and phospholipids increased during the starvation period indicating the mobilisation of fatty acids from triacylglycerols for use in catabolism and in the formation of biomembrane lipids. The distribution pattern of radioactivity from [U–]22:6n−3 in the fatty acids of the nauplii demonstrates that Artemia are capable of retroconverting 22:6n−3 to 20:5n−3.
Two Artemia species (Artemia franciscana, GSL strain and a population from Artemia sinica, ARC No. 1188) were enriched with two different emulsions containing high levels of docosahexaenoic acid (DHA) (23 and 44% of total fatty acids, respectively) in filtered seawater (30 ppt) at 28 °C. After enrichment nauplii were starved for 72 h at three different temperatures (6.1, 12.2 and 22 °C). Following enrichment the DHA content and ratio reached a maximum 41.2 and 42.8 mg g−1 dry weight and 1.88 and 2.09 in A. franciscana and A. sinica, respectively. During starvation at 12.2 °C the DHA content in A. franciscana decreased steadily throughout the starvation period towards 1.11–2.89 mg g−1 dry weight ( ratio of 0.4) after 72 h, whereas in A. sinica the DHA content was > 20 mg g−1 dry weight ( ratio of 1.7–2). A quantitative reduction of DHA in A. sinica was observed only during the first 24 h of the starvation period. The degradation rate of DHA in A. franciscana increased with rising temperature (22 °C) and decreased at the lowest temperature (6.1 °C). This was not the case for A. sinica, during starvation at different temperatures the DHA level in A. sinica remained at a relatively high and constant level.
The requirement for dietary (n−3) PUFA for growth, survival and swim bladder development in gilthead seabream, Sparus aurata, larvae was tested using rotifers with various levels of (n−3) PUFA. Four rotifer treatments differing in their (n−3) PUFA content (0.8, 3.2, 5.1 and 8.4 mg/g dry body weight, DBW) were prepared by feeding them combinations of various oil emulsions and dried squid (rich in both EPA (20:5n−3) and DHA (22:6n−3)). A fifth treatment consisted of rotifers enriched on the algae Nannochloropsis sp. Regression analyses, from the emulsion treatments, were performed on various relationships between rotifer (n−3) PUFA levels and larval phospholipid and growth. The equations describing these correlations were then used to examine whether the same parameters in larvae fed Nannochloropsis-enriched rotifers were a result of the dietary (n−3) PUFA levels they consumed or some other nutritional factor.The results indicate that dietary (n−3) PUFA significantly (P<0.05) influence fish moisture and lipid levels and are necessary for good growth in larval gilthead seabream. Fish fed the highest levels of (n−3) PUFA (8.4 mg/g DBW) showed a four-fold increase in growth (1263% vs. 312%) over larvae offered rotifers with the lowest levels of (n−3) PUFA (0.8 mg/g DBW). In contrast, there was no compelling evidence that EPA and/or DHA significantly (P<0.05) affected larval survival or swim bladder inflation and suggests that these dietary factors, at least in the development of the swim bladder, play a more subordinate role. Larval growth on the Nannochloropsis treatment was strongly associated with EPA and implies that, despite other sources of nutrition in the algal media, this fatty acid determines the dietary value of these rotifers for growth in Sparus aurata larvae.
The dried cysts of the brine shrimp Artemia salina are used all over the world as a most convenient source of live crustacean nauplii which are indispensable for the larval stages of many fishes and crustaceans. With the expansion of mariculture, the demand for the resting eggs of Artemia has greatly increased and at certain moments of the year it exceeds the offer. Hence it is even more regrettable that in most mariculture farms a considerable wastage of this precious live food occurs: the nauplii are usually hatched in uncontrolled conditions, and the instar stage at which the Artemia larvae are offered to the predator is not considered and varies from one experiment to another. From fundamental research on the hatching and molting rate of Artemia larvae it appears that the water temperature has an important influence on the latter two processes. The biochemical data reported in this paper, reveal drastic changes in the dry- and ash weight and in the caloric- and lipid content of Artemia nauplii when they molt from the 1st into the 2nd and 3rd instar stages. In order to keep the energetic value as high as possible, it is clear that the cysts should be hatched under strictly controlled conditions and should be fed to the larval fishes or crustaceans as soon as possible after hatching.
1. [1-14C]linolenic acid was injected into the rainbow trout, Salmo gairdnerii, ayu, Plecoglossus altivelis, eel, Anguilla japonica, red sea bream, Chrysophrys major, rockfish, Sebastiscus marmoratus, globefish, Fugu rubripes rubripes and prawn, Penaeus japonicus (molting stage D"1-D2), and the bioconversion of linolenic acid (18:3 omega 3) to highly unsaturated fatty acids such as eicosapentaenoic (20:5 omega 3) and docosahexaenoic (22:6 omega 3) acids was investigated. 2. Linolenic acid was converted to 20:5 omega 3 and 22:6 omega 3 intensively in the rainbow trout, moderately in the ayu, eel and prawn, but slightly in the red sea bream, rockfish and globefish. 3. These results were discussed in relation to the essential fatty acid requirements of the aquatic animals.
Docosahexaenoic acid (DHA), the major biosynthetic product of the omega-3 family of fatty acids, is uniquely concentrated in the retina and synaptic membranes. In the perinatal period of life, when the bulk of synaptogenesis and photoreceptor biogenesis takes place, large requirements of DHA may be met first by the placenta and then by maternal milk. Linolenic acid (LLA), the precursor of DHA, is the most prevalent fatty acid of the omega-3 series in the stomach contents of newborn mice. In this study we have investigated the fate of radiolabeled LLA and DHA injected intraperitoneally in developing postnatal mouse. Our results show that radiolabeled LLA was taken up by the liver and DHA was synthesized; at 72 hrs post-injection about 90% of the label had been converted to DHA. Since there was a time-dependent buildup of radiolabeled DHA in blood plasma with negligible early uptake of LLA by the brain and retina, we hypothesize that the liver may secrete lipoproteins containing DHA and that this process is regulated by the nervous tissue.
The molecular-species compositions of the diacyl classes of the major phospholipids from the brain and retina of rainbow trout (Salmo gairdneri) were determined. A total of 46 possible species was identified. Didocosahexaenoyl species were major components of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) from retina, comprising 14.1, 41.3 and 28.3% of the respective totals. This species was also abundant in PE and PS from brain, accounting for 14.9 and 19.9% of the totals respectively. Small amounts of di-polyunsaturated fatty acid species [C22:6(n-3) with C20:5(n-3), and C22:6(n-3) with C22:5(n-3)] were also found in these phospholipids. Phosphatidylinositol (PI) from both tissues contained no di-polyunsaturated fatty acid species. Retinal PI contained 40.1% C18:0-C20:4(n-6) with 14.9% of C18:0-C20:5(n-3); brain PI contained 42.3% of C18:0-C20:5 and 10.4% of C18:0-C20:4 species. Brain PC contained a substantial amount of nervonic acid-containing species with the pair C18:1-C24:1/C24:1-C18:1 comprising 8.9% of the total.
Lipid decomposition studies in frozen fish have led to the development of a simple and rapid method for the extraction and purification of lipids from biological materials. The entire procedure can be carried out in approximately 10 minutes; it is efficient, reproducible, and free from deleterious manipulations. The wet tissue is homogenized with a mixture of chloroform and methanol in such proportions that a miscible system is formed with the water in the tissue. Dilution with chloroform and water separates the homogenate into two layers, the chloroform layer containing all the lipids and the methanolic layer containing all the non-lipids. A purified lipid extract is obtained merely by isolating the chloroform layer. The method has been applied to fish muscle and may easily be adapted to use with other tissues.Lipid decomposition studies in frozen fish have led to the development of a simple and rapid method for the extraction and purification of lipids from biological materials. The entire procedure can be carried out in approximately 10 minutes; it is efficient, reproducible, and free from deleterious manipulations. The wet tissue is homogenized with a mixture of chloroform and methanol in such proportions that a miscible system is formed with the water in the tissue. Dilution with chloroform and water separates the homogenate into two layers, the chloroform layer containing all the lipids and the methanolic layer containing all the non-lipids. A purified lipid extract is obtained merely by isolating the chloroform layer. The method has been applied to fish muscle and may easily be adapted to use with other tissues.
Manipulation of the fatty acid profile in Artemia offspring produced in intensive culture systems
- Lavens
Manual for the Culture and use of Brine Shrimp Artemia in Aquaculture. Manual prepared for the Belgian Administration for Development Cooperation and the Food and Agriculture Organization of the United Nations
- P Sorgeloos
- P Lavens
- P Léger
- W Tackaert
- D Versichele