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Visual comparison of the body size and the size of the egg sacs of Paracyclopina nana ovigerous females fed on different microalgal diets. Additional supporting data on ovigerous females respective prosome length and clutch size can be found in Dayras et al. (2020). R, Rhodomonas salina; T, Tisochrysis lutea; P, Pavlova lutheri.
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Copepods represent an interesting alternative or a complement live food to brine shrimps and rotifers commonly used in aquaculture. They constitute the natural prey of many fish species and therefore do not require a potential nutritional enrichment. But an optimization of the microalgal diets used to feed copepods is essential to improve their mas...
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... Copepods have rich content of eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA). These fatty acids greatly support the metabolism, development and survival of marine fish larvae (Dayras et al., 2021;Nielsen et al., 2021). Micro-sized copepods (adult <1 mm), owning their tiny nauplii (< 90 μm), are great supplementary or alternative diets for ornamental fish larvae. ...
... The nutritional profile of the microalgae, especially the content of dietary polyunsaturated fatty acids (i.e. EPA and DHA) play important role in the physiological functions for sustaining copepod survival, (Pan et al., 2018;Dayras et al., 2021). Our findings revealed that the PRO and ISO diets are more beneficial for sustaining the fecundity and population growth of P. ishigakiensis than the CHL and TET diets. ...
This study aims to investigate the optimal culture conditions of the marine calanoid copepod Pseudodiaptomus ishigakiensis, which is considered emerging live feed for marine larviculture. The effects of temperatures (20 • C, 25 • C, 30 • C and 35 • C) and microalgal diets Isochrysis galbana (ISO), Proteomonas sulcata (PRO), Chlorella sp. (CHL) and Tetraselmis chuii (TET) on the fecundity, population growth rate, composition of developmental stages and fatty acid composition of P. ishigakiensis were evaluated. The highest population growth rate (60.6 ± 4.9 ind./day) was found at 30 • C with the significantly-highest number of naupliar individuals (726.7 ± 30.6 ind.) and a high level of fecundity (14.4 ± 0.7 eggs/female). Whereas the lowest population growth was found at 35 • C (0.4 ± 0.2 ind./day). In the diet experiment, the population growth rate (73.8 ± 1.9 ind./day) was the highest in the PRO treatment with a great number of naupliar individuals (912.50 ± 24.7 ind.) and fecundity (13.4 ± 0.6 eggs/female). Both TET and CHL treatments showed the lowest population growth (0.5 ± 0.1 ind./ day and 0.2 ± 0.1 ind./day, respectively) and absence of ovigerous female at the end of experiment, which indicated their unsuitability as feeds for P. ishigakiensis. Fatty acid compositions of copepods were affected by the fatty acid content of their microalgal diets. The copepods fed on ISO and PRO contained higher levels of eico-sapentaenoic acid (EPA, C20:5 n-3; 4.51 ± 1.29-5.42 ± 0.64%) and docosahexaenoic acid (DHA, C22:6 n-3; 4.00 ± 0.34-5.92 ± 1.28%) composition compared to CHL and TET (EPA: 0.48 ± 0.15-2.65 ± 1.27%; DHA: 1.68 ± 0.26-1.89 ± 0.14%). This study revealed the optimal culture conditions and nutritional value of the copepod P. ishigakiensis, which provides implications for the managements of their mass culture, and utilization in marine larviculture.
... Our findings of beneficial impacts of including NSS microalgae mixture in Nile tilapia diets on deposition of DHA and EPA (two important omega-3 PUFAs) are also consistent with a previous observation [75], where higher PUFAs were observed with increasing the supplementation level of Schizochytrium species enriched with DHA fatty acid. Moreover, incorporation of microalgae enriched with DHA and EPA increased their contents in copepods [76]. Additionally, feeding of sea bream on diets enriched with microalgae blends including Nannochloropsis, oculata, and Schizocthytrium species displayed an increased long-chain n-3-PUFAs, DHA, and EPA levels [77]. ...
The oxidative stress facing fish during intensive production brings about diseases and mortalities that negatively influence their performance. Along with that, the increased awareness of omega-3 polyunsaturated fatty acids (omega-3-PUFAs) health benefits has been triggered the introduction of alternative additives in aqua feed that cause not only modulation in fish immune response but also fortification of their fillet. In this context, the role of microalgae mix (NSS) containing Nannochloropsis oculate and Schizochytrium and Spirulina species, which were enriched with bioactive molecules, especially EPA and DHA, was assessed on Nile tilapia’s performance, fillet antioxidant stability, immune response, and disease resistance. Varying levels of NSS (0.75, 1.5, and 3%) were added to Nile tilapia’s diet for 12 weeks and then a challenge of fish with virulent Aeromonas hydrophila (A. hydrophila) was carried out. Results showed that groups fed NSS, especially at higher levels, showed an improved WG and FCR, which corresponded with enhanced digestive enzymes’ activities. Higher T-AOC was detected in muscle tissues of NSS3.0% fed fish with remarkable reduction in ROS, H2O2, and MDA contents, which came in parallel with upregulation of GSH-Px, CAT, and SOD genes. Notably, the contents of EPA and DHA in fillet were significantly increased with increasing the NSS levels. The mean log10 counts of pathogenic Vibrio and Staphylococcus species were reduced, and conversely, the populations of beneficial Lactobacillus and Bacillus species were increased more eminent after supplementation of NSS3.0% and NSS1.5%. Moreover, regulation of the immune response (lysozyme, IgM, ACH50, NO, and MPO), upregulation of IL-10, TGF-β, and IgM, and downregulation of IL-1β, TNF-α, HSP70, and COX-2 were observed following dietary higher NSS levels. After challenge, reduction in A. hydrophila counts was more prominent, especially in NSS3.0% supplemented group. Taken together, the current study encourages the incorporation of such microalgae mix in Nile tilapia’s diet for targeting maximum performance, superior fillet quality, and protection against A. hydrophila.
... Rhodomonas spp. have been deemed a high-quality diet for numerous filter-feeding invertebrates including copepods (Dayras et al. 2021;Knuckey et al. 2005;Ohs et al. 2010), artemia (Seixas et al. 2009), rotifers (Coutinho et al. 2020), scallops (Tremblay et al. 2007), oysters (Brown et al. 1998), mussels (Jose Fernández-Reiriz et al. 2015), and sea urchins (Castilla-Gavilán et al. 2018;Gomes et al. 2021;Hinegardner 1969). Nutritional factors, including cell size and morphology, biochemical composition, and/or digestibility, vary by microalgae species (Brown et al. 1997;Guedes and Malcata 2012) and can help to explain improved D. antillarum larval performances from diets containing R. lens. ...
Slow or nonexistent natural recovery of the Caribbean long-spined sea urchin (Diadema antillarum) following a mass mortality event in 1983-1984 has prompted interest in hatchery-origin production and restocking to aid coral-reef restoration. A critical first step is the ability to propagate D. antillarum from gametes, at scale. However, a unique larval biology and difficult and lengthy culture period of ~ 40 days has resulted in inconsistent success over the past 20-plus years. The purpose of this study was to develop protocols for rearing D. antillarum within a novel 1800-L recirculating aquaculture system capable of scaled production. Five separate experiments investigated larval development in response to diet quantity, diet composition, and initial stocking density within 40-L replicate culture tanks. The initial experiment was used to develop a microalgae reference diet consisting of Tisochrysis lutea and Chaetoceros sp. and revealed similar growth and survival between high quantity (40.0 × 10 3 cells mL −1) and low quantity (10.0 × 10 3 cells mL −1) treatments at 21 days post-fertilization (DPF). Experiments 2-4 examined diet quality by comparing carbon-equivalent microalgae compositions. Mixed diets containing Rhodomonas lens outperformed the reference diet in multiple experiments and a tripartite diet containing all three species resulted in significantly higher survival at 42 DPF. The highest growth overall occurred from a monoalgal R. lens diet, which indicated that this species is critically important. Further observations of density-dependent growth dynamics revealed that initial stocking densities > 1 larvae mL −1 significantly reduced growth over 28 DPF. Data generated were used to establish fundamental larviculture protocols that have since led to the production of over 1000 juveniles.
... Rhodomonas spp. have been deemed a high-quality diet for numerous filter-feeding invertebrates including copepods (Dayras et al. 2021;Knuckey et al. 2005;Ohs et al. 2010), artemia (Seixas et al. 2009), rotifers (Coutinho et al. 2020), scallops (Tremblay et al. 2007), oysters (Brown et al. 1998), mussels (Jose Fernández-Reiriz et al. 2015), and sea urchins (Castilla-Gavilán et al. 2018;Gomes et al. 2021;Hinegardner 1969). Nutritional factors, including cell size and morphology, biochemical composition, and/or digestibility, vary by microalgae species (Brown et al. 1997;Guedes and Malcata 2012) and can help to explain improved D. antillarum larval performances from diets containing R. lens. ...
Slow or nonexistent natural recovery of the Caribbean long-spined sea urchin ( Diadema antillarum ) following a mass mortality event in 1983–1984 has prompted interest in hatchery-origin production and restocking to aid coral-reef restoration. A critical first step is the ability to propagate D. antillarum from gametes, at scale. However, a unique larval biology and difficult and lengthy culture period of ~ 40 days has resulted in inconsistent success over the past 20-plus years. The purpose of this study was to develop protocols for rearing D. antillarum within a novel 1800-L recirculating aquaculture system capable of scaled production. Five separate experiments investigated larval development in response to diet quantity, diet composition, and initial stocking density within 40-L replicate culture tanks. The initial experiment was used to develop a microalgae reference diet consisting of Tisochrysis lutea and Chaetoceros sp. and revealed similar growth and survival between high quantity (40.0×10 ³ cells ml ⁻¹ ) and low quantity (10.0×10 ³ cells ml ⁻¹ ) treatments at 21 DPF. Experiments 2–4 examined diet quality by comparing carbon-equivalent microalgae compositions. Mixed diets containing Rhodomonas lens outperformed the reference diet in multiple experiments and a tripartite diet containing all three species resulted in significantly higher survival at 42 DPF. The highest growth overall occurred from a monoalgal R. lens diet, which indicated that this species is critically important. Further observations of density-dependent growth dynamics revealed that initial stocking densities > 1 larvae ml ⁻¹ significantly reduced growth over 28 DPF. Data generated were used to establish fundamental larviculture protocols that have since led to the production of over 1,000 juveniles.
... Microalgae plays a fundamental role in aquatic food webs by converting solar energy into bioavailable organic compounds and trophic resources. These micro-sized autotrophs are sustainable food item for aquaculture (Hemaiswarya et al., 2011), and are used as live feeds for several marine organisms such as bivalves (Tahir and Ransangan, 2021;Hassan et al., 2022), zooplankton (Pan et al., 2018;Dayras et al., 2021), larvae of crustacean (Sharawy et al., 2020;Sandeep et al., 2021), and echinoderm (Militz et al., 2018;Gomes et al., 2021). In marine hatcheries, the usage of microalgae could be categorized in three scenarios: (i) direct diet to provide nutrients to early developmental stages (Camus et al., 2021;Dayras et al., 2021); (ii) natural enrichment ingredients to zooplankton live feed organisms (Fu et al., 2021); (iii) water conditioners: microalgae are added to create "green water" which conditions water quality, reduces bacterial loads, increases visual contrast, and prey detection (Basford et al., 2021). ...
... These micro-sized autotrophs are sustainable food item for aquaculture (Hemaiswarya et al., 2011), and are used as live feeds for several marine organisms such as bivalves (Tahir and Ransangan, 2021;Hassan et al., 2022), zooplankton (Pan et al., 2018;Dayras et al., 2021), larvae of crustacean (Sharawy et al., 2020;Sandeep et al., 2021), and echinoderm (Militz et al., 2018;Gomes et al., 2021). In marine hatcheries, the usage of microalgae could be categorized in three scenarios: (i) direct diet to provide nutrients to early developmental stages (Camus et al., 2021;Dayras et al., 2021); (ii) natural enrichment ingredients to zooplankton live feed organisms (Fu et al., 2021); (iii) water conditioners: microalgae are added to create "green water" which conditions water quality, reduces bacterial loads, increases visual contrast, and prey detection (Basford et al., 2021). Based on a variety of microalgal characteristics (Table 1) several aspects should be considered in applications: (i) cell size: that should be compatible to the ingestion capacities of the larvae; (ii) cell structure: property of cell walls or skeletons (e.g., cellulose, SiO 2 , or CaCO 3 ) could affect the efficiency of ingestion and digestion; (iii) nutritional profile: content (actual amount) and composition (percentage) of various bioactive nutrients should be taken into account according to the nutritional requirements of their consumers (Borowitzka, 2013;Pan et al., 2018;Dayras et al., 2021). ...
... In marine hatcheries, the usage of microalgae could be categorized in three scenarios: (i) direct diet to provide nutrients to early developmental stages (Camus et al., 2021;Dayras et al., 2021); (ii) natural enrichment ingredients to zooplankton live feed organisms (Fu et al., 2021); (iii) water conditioners: microalgae are added to create "green water" which conditions water quality, reduces bacterial loads, increases visual contrast, and prey detection (Basford et al., 2021). Based on a variety of microalgal characteristics (Table 1) several aspects should be considered in applications: (i) cell size: that should be compatible to the ingestion capacities of the larvae; (ii) cell structure: property of cell walls or skeletons (e.g., cellulose, SiO 2 , or CaCO 3 ) could affect the efficiency of ingestion and digestion; (iii) nutritional profile: content (actual amount) and composition (percentage) of various bioactive nutrients should be taken into account according to the nutritional requirements of their consumers (Borowitzka, 2013;Pan et al., 2018;Dayras et al., 2021). In general, the production of marine microalgal Chlorophytes (e.g., Nannochloropsis sp. and Tetraselmis sp.) can easily be sustained at high cell concentration and wide environmental conditions. ...
In marine larviculture, farmed larvae mainly rely on the alimentation of a group of small-sized phytoplankton and zooplankton referred to as live feed. Under the diversifying demands of human consumption and ornamental aquarium industry, new species of live feed and their innovative production methods are essential focuses for sustainable larviculture of many emerging fish and invertebrate species. The selection of proper live feed for larval feeding is based on several parameters, such as size, morphology, nutritional value, stock density, and growth rate. This review aims to highlight the biological characteristics, production approach, common larviculture applications as well as recent innovations in the aquaculture technology of live feed organisms (microalgae, ciliated protists, rotifer, Artemia, copepod, and others).
... Our data showed no difference in body size between O. nana that were fed single and mixed algae diets. This is not the case in other cyclopoids, such as Paracyclopina nana, which were found to have larger body sizes when fed mixed diets [91]. The body size range for each stage of O. nana recorded in this study corresponds to the sizes reported in natural and cultured conditions by other authors, indicated in Table 4. ...
Several species of the planktonic free-living genus Oithona have been successfully used in the larviculture of marine fish and shrimp. However, few studies have been published that allow us to estimate the potential of Oithona nana culture under controlled conditions. This work evaluated the effect of the microalgae Isochrysis galbana and Chaetoceros calcitrans as single (200,000 cells/mL) and mixed diets (100,000 + 100,000 cells/mL) on population and individual growth, ingestion rate, number of spawnings, fertility, development time by stage, and sex ratio of O. nana. We cultured this copepod at 28 ± 0.5 °C, 35 PSU salinity, 125 lux, and 12:12 photoperiod. Results showed that diet had no effect on the final population level (6273–7966 ind/L) or on individual growth, nor on sex ratio, with less males than females. With C. calcitrans, O. nana had a higher filtration rate (57 ng C/ind/day). On the other hand, a mixed diet induced a higher number of spawns (0.4 events/day) and nauplii per spawn (23 ind). Similarly, a single or mixed diet, containing I. galbana, accelerated the development rate by 6.33–7.00 days. We concluded that O. nana can be cultured with both microalgae, indicating its potential use in an intensive system for production. However, more research is required to improve the productivity of O. nana rearing.
... Therefore, optimizing the culture conditions has been the focus of previous research. Many factors could affect copepod culture reproductivity and past research has been focused on temperature, salinity, and both quality and quantity of their food (e.g., Holste and Peck, 2006;Camus et al., 2009;Camus and Zeng, 2010;Nogueira et al., 2017;Nguyen et al., 2020;Choi et al., 2021;Dayras et al., 2021), while the effects of photoperiod is less studied despite photoperiod has been shown to significantly affect culture productivity of two Acartia species, i.e., Acartia tonsa and Acartia sinjiensis (Camus and Zeng, 2008). Photoperiod is well known as one of the most important environmental factors regulating reproductive activity of aquatic animals, including copepods, and it has been reported to influence number of eggs produced by females, as well as the type (i.e., subitaneous vs. diapause eggs) of eggs produced (Marcus, 1982;Peck and Holste, 2006;Camus, 2012;Fereidouni et al., 2015). ...
The paracalanid copepod, Bestiolina amoyensis, is a widely distributed species occurring in subtropical inshore waters across the Pacific Ocean. Its small size, herbivorous feeding habit, and high adaptability make the species one of the most promising candidates as potential live feed for hatchery larval rearing. This study investigated effects of different feeding density of microalgae Isochrysis spp. (1 × 10⁵, 2 × 10⁵, 3 × 10⁵, 4 × 10⁵, and 5 × 10⁵ cells ml–1) and photoperiod (8L:16D, 12L:12D, and 16L:8D) on productivity-related parameters, including egg production, female life expectancy and population dynamics of B. amoyensis. Results showed that total egg output over female lifespan, final population size and intrinsic rate of population of 12L:12D photoperiod treatments were always the highest among three photoperiod conditions, especially at the food concentration of 4 × 10⁵ cells ml–1, indicating B. amoyensis had high reproductive performance and the population was in a more stable status. The number of nauplii from 4 × 10⁵ cells ml–1 algal concentration treatment accounted for 75% of the population, and the ratio of females to males approaching 1:1 when photoperiod was 12L:12D; female life expectancy was 10.5 ± 0.6 days. In conclusion, our results showed that Isochrysis spp. is a suitable feed for B. amoyensis with an optimal concentration at 4 × 10⁵ cells mL–1; the optimal photoperiod for B. amoyensis rearing is 12L:12D. The relatively long reproductive lifespan and high intrinsic population increase rate make B. amoyensis a good candidate to develop culture techniques for hatchery larval rearing.
The accumulation of plastic debris around the world, especially in marine environments, has been well documented during the past decades. Recent studies have found that inorganic surfaces of microplastics (MPs) can be used by microorganisms as living substrates and form an ecosystem named “plastisphere.” Some microorganisms present in MPs are capable of producing polymer-degrading enzymes. In addition, MPs can also serve as vectors and carry microorganisms (including potential pathogens) into higher trophic levels through their ingestion by animals. In this study, impacts on copepod microbiota during chronic exposure to MPs were investigated by exposing copepods to a classic single-use polymer (low-density polyethylene (LDPE)) and a biodegradable polymer (polybutylene adipate terephthalate (PBAT)). Copepods were exposed to “virgin” and “weathered” MPs during four generations at an environmentally relevant concentration of 300 µg/L, followed by one “detoxification” generation without MP exposition. Impacts of MP exposure on copepod microbiota were investigated using 16S rRNA gene high-throughput sequencing. The result of nonmetric multidimensional scaling (NMDS) analysis showed that copepods (with or without MP exposure) carried distinguishable microbiota as compared with the microbiota of water and microalgae used for maintaining copepods. According to the results of permutational analysis of variance (PERMANOVA), the microbiota of MP-exposed (both PBAT and LDPE) copepods was significantly different from the microbiota of unexposed copepods during generations one to four. After “detoxification,” however, no significant difference in microbiota composition was observed among all generation five copepods. Altogether, impacts on copepod microbiota of MP exposure for multiple generations were observed, despite plastic origin (biodegradable or not) and aging conditions. Furthermore, copepod microbiota seemed to return to their original structure as soon as the MP exposure stopped.
