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Morphological development and growth of Bunni, Mesopotamichthys sharpeyi (Günther, 1874), larvae reared in the laboratory
Abstract
The early development of the endemic cyprinid, Bunni Mesopotamichthys sharpeyi (Günther, 1874) larvae has been determined according to morphological changes and total length, standard length, head length, thickness of larvae, eye diameter and snout length measurements. The results showed that the initial period of Bunni larval life can be divided into two phases: early stages dependent upon endogenous nutrient sources, and a second phase of stages dependent upon exogenous food sources. In the first three days of larvae development there was a gradual yolk sac reduction after which there was a switch to exogenous feeding. From the fourth to eleventh day, the final development of heart, gill, air bladder, fins and intestine were observed. The newly hatched larvae and the fifteen day old larvae were 6.26±0.14 and 8.35±0.17 mm in mean total length (TL), respectively. The mouth opened 2-4 days after hatching (DAH). The larvae started to swim actively within 2-3 days and the yolk sac had been totally absorbed at 4-5 DAH. Notochord flexion began at 11 DAH. Compare to other cyprinids, the larval development of Mesopotamichthys sharpeyi is similar to other Meso pota-michthys species.
... Cichlidae showed differentiation compared to other species (Maan and Sefc, 2013;Ahmadi et al., 2013). Furthermore, it is assumed that identical pigmentation can imply similar function while body coloration is inextricably referred to diversification as well as responding to both natural and sexual selection (Meyer, 1993;Kocher, 2004;Maan and Sefc, 2013). ...
The giraffe cichlid Nimbochromis venustus Boulenger, 1908 is a well-known species in aquarium trade. The laboratory-reared electric giraffe cichlid was studied in terms of early morphological development and allometric growth pattern from hatching until the juvenile stage i.e. 51 dph. Total length increased linearly from hatching until 51 dph, with a high regression coefficient. The yolk sac exhaustion completed throughout 15 days. Significant morphological and morphometric variations occurred before the yolk sac absorption and early juvenile stage by evolving the anterior and posterior body section which improve swimming ability and food capturing. Positive growth coefficient of the body and trunk lengths were occurred after inflexion point coinciding with development of digestive system function. Eye diameter showed negative allometry at the inflexion point of 9.3 mm, continuing with positive growth rate until day 51. Body shape variation in early life history revealed consequent development in anterior and posterior body section in preflexion phase and development of body and trunk length in post flexion phase to support high survival of larvae. The present study emphasizes ontogenic study of different species to interpret biology and ecology of fish in association with evolutionary biology.
The present study was conducted in Electric Blue Cichlid Sciaenochromis
fryeri in early larval developmental stages from the fifth day post hatching
(DPH) until 51 DPH to determine day of transforming from embryo to
juvenile. Morphological characteristics were evaluated by using ImageJ
software. Allometric growth patterns were calculated based on the formula
Y=aXb. Yolk sac depletion was occurred on day 9. Scales were developed on
day 19 and finaly developed juvenile shape. allometric pattern of different
body segments were calculated according to isometry, positive, and negative
allometry. Positive allometry of head and tail prior to inflexion point and
variation in allometric growth pattern in different body segment determine
priorities of organogenesis for survival in fish early life history. The obtained
results showed consistency between the larval morphological changes and
development of organs related to sensory movements and larval behavior.
Every morphological change in larvae displays the development and evolution
of one of the organs involved in feeding, breathing, swimming and sensory
organs.
The present study provides a new and updated checklist of the freshwater fishes of Iran. The
confirmed freshwater fishes of Iran comprise 257 species in 106 genera, 29 families, 18 orders and 3
classes. The most diverse order is the Cypriniformes with 162 species or 63.04% of the fauna, followed
by Perciformes (32 species, 12.45%), Cyprinodontiformes (17 species, 6.61%) and Clupeiformes (11
species, 4.28%). The most diverse family is the Cyprinidae with 111 confirmed species (43.19%)
followed by Nemacheilidae (44 species, 17.12%), Gobiidae (24 species, 9.34%), Cyprinodontidae (14
species, 5.45%), Clupeidae (10 species, 3.89%), Cobitidae (7 species, 2.72%) and Salmonidae (7
species, 2.72%). Twenty-two families have 6 or fewer species. Fourteen families have only one species.
Endemics comprise 73 species (28.40% of total fauna) in seven families although this is expected to
increase, as new species are describing. Cyprinidae with 30 endemics (41.10% of endemic species) is
ranked first followed by Nemacheilidae with 25 (34.25%), Cyprinodontidae with 11 (15.07%), Cobitidae
with 4 (5.48%), and Cichlidae, Gobiidae and Sisoridae, each with one species (1.37% each). An
additional 23 species require confirmation of their presence in Iran. Twenty-seven exotic species in nine
families are listed here. Cyprinidae with 11 species (40.74% of exotic species) is ranked first followed
by Salmonidae (5 species, 18.52%), Poeciliidae with 3 species (11.11%), Mugilidae and Cichlidae both
with 2 species (7.41% each) and 4 families each with only one species (3.70% each). Exotic species
containing, Oncorhynchus mykiss, Ctenopharyngodon
idella, Hypophthalmichthys molitrix,
Hypophthalmichthys nobilis and Cyprinus carpio transplanted by Iranian Fisheries Organization (Shilat)
for aquaculture developments throughout Iran, but Alburnus hohenackeri, Carassius auratus, Carassius
gibelio, Hemiculter leucisculus, Pseudorasbora parva, and Gambusia holbrooki, transferred with them
inadvertently to Iranian water resources. Certain nominal species can be regarded as species
complexes, probably containing several undescribed species. The genera Capoeta, Squalius, Alburnus
and Barbus are wide-ranging and complexes genus in Iran, that systematics of them need careful reassessment.
The present study provides a new and updated checklist of the freshwater fishes of Iran. The
confirmed freshwater fishes of Iran comprise 257 species in 106 genera, 29 families, 18 orders and 3 classes. The most diverse order is the Cypriniformes with 162 species or 63.04% of the fauna, followed by Perciformes (32 species, 12.45%), Cyprinodontiformes (17 species, 6.61%) and Clupeiformes (11 species, 4.28%). The most diverse family is the Cyprinidae with 111 confirmed species (43.19%) followed by Nemacheilidae (44 species, 17.12%), Gobiidae (24 species, 9.34%), Cyprinodontidae (14 species, 5.45%), Clupeidae (10 species, 3.89%), Cobitidae (7 species, 2.72%) and Salmonidae (7 species, 2.72%). Twenty-two families have 6 or fewer species. Fourteen families have only one species. Endemics comprise 73 species (28.40% of total fauna) in seven families although this is expected to increase, as new species are describing. Cyprinidae with 30 endemics (41.10% of endemic species) is ranked first followed by Nemacheilidae with 25 (34.25%), Cyprinodontidae with 11 (15.07%), Cobitidae with 4 (5.48%), and Cichlidae, Gobiidae and Sisoridae, each with one species (1.37% each). An additional 23 species require confirmation of their presence in Iran. Twenty-seven exotic species in nine families are listed here. Cyprinidae with 11 species (40.74% of exotic species) is ranked first followed by Salmonidae (5 species, 18.52%), Poeciliidae with 3 species (11.11%), Mugilidae and Cichlidae both with 2 species (7.41% each) and 4 families each with only one species (3.70% each). Exotic species containing, Oncorhynchus mykiss, Ctenopharyngodon idella, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis and Cyprinus carpio transplanted by Iranian Fisheries Organization (Shilat) for aquaculture developments throughout Iran, but Alburnus hohenackeri, Carassius auratus, Carassius gibelio, Hemiculter leucisculus, Pseudorasbora parva, and Gambusia holbrooki, transferred with them inadvertently to Iranian water resources. Certain nominal species can be regarded as species complexes, probably containing several undescribed species. The genera Capoeta, Squalius, Alburnus and Barbus are wide-ranging and complexes genus in Iran, that systematics of them need careful reassessment.
Different approaches to definitions used to delimit and classify fish ontogeny intervals, especially during early life history, are reviewed, discussed and commented in order to simplify, generalise and, in some reasonable extent, to unify them, especially in studies of the European freshwater fishes. The thresholds separating subsequent life history periods, types of ontogeny and concepts for metamorphosis, direct and indirect development were discussed. No principal differences exist between the transitory and indirect types of development and that terms like larva and metamorphosis should follow a convention in ichthyology, regardless of whether metamorphic processes are manifested suddenly in a relatively short interval of development or if they progress gradually in minor consecutive changes and during several developmental steps. It was recommended to avoid using the confusing term 'alevin' in scientific literature.
The purpose of this study was to determine the early growth scheme and development stages of the red porgy, Pagrus pagrus larvae through the transition from endogenous and exogenous food sources using as main criterion the body lenght gained at each development stage. The initial period of the species' larval life can be divided into three phases: a) an initial phase characterised by no motility (0-24 h time after hatching; TAH; b) a phase characterised by active movement and exploitation of the endogenous food reserves (24 h to 96 TAH); and c) a phase characterised by the transition from endogenous to exogenous food (96 to 168 TAH). It was observed that there does not exist an overlapping period between phases b and c and therefore, there exists a gap of 24-36 hours during which the larvae have exhausted their internal food reserves (oil globule and yolk sac) while the digestive tract is not ready to digest external food items (rotifers). We observed a massive larval mortality reaching almost 85% between days 3 and 7 after hatching.
The early development of the cyprinid fish Barbus sharpeyi, from fertilization to juvenile, was recorded using living material. Three embryonic steps, one free embryo and four larval steps were identified. Hatching occurred between 70-79 h (post-activation); the free embryo period was extremely short in duration (5-13 h). The transition from larva to juvenile occurred in 50 days when the fish were fully scaled and the lateral line organ was clearly visible. Indication of different degrees of complexity of physiological and morphological developments within each step were clear through both embryo and larva periods of development as steps increased in duration.
This study illustrates the embryonic development of false clownfish, Amphiprion ocellaris under laboratory condidions. Broodstock were reared and spawned under captive conditions. The newly deposited eggs were prolate speherical in shape with orange-pink and numerous oil droplets in the yolk. Cleavage was fast and the first division took place at 1:20 h after insemination. Blastulation was observed 4 hours later, followed by gastrulation after 12 h with a yolk volume at 0.63 mm3. Organogenesis process occurred after 22h when the blastopores closed and notochord started to form. The embryonic stage was reocrded at 24h with the appearance of forebrain, midbrain, hindbrain, melanophores on yolk-sac and 22 somites. Other organs had developed well 31 hours later. Heart started beating and blood circulation occurred at 78h. Red pigmentation (erytrophores) appeared at 96 h with a yolk volume at 0.21 mm3. Mouth developed well and eye was noticeable at 120 h. The head, pectoral fin and tail moved frequently at 144 h and embryo reached the pre-hatching stage at 168 h. The embryo started to hatch at 180 h after incubation
Larval development of the himri barbel, Barbus luteus Heckel, reared at 19-22 ¡C in natural daylight is described. Morphological and some functional character appearances were similar to the main ontogenetic steps of development in most cyprinids. Small hatched larvae attained both metamorphosis and a length of 10.5 mm after almost 35 days. Relative growth of the selected body proportions demonstrated typical priorities in growth compared to the length. An ontogenetic index was inferred from applying age and length criteria at metamorphosis as a scale for ontogenetic events.
Embryonic, larval, and juvenile development of an Indian cyprinid fish, Chela dadiburjori, is described from laboratory-reared specimens. The eggs, measuring 0.7–0.9mm in diameter, were demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk and no oil globule. Hatching occurred 50–61h after fertilization at ca. 27C. The newly hatched larvae, measuring 2.4–2.6mm in body length (BL), had melanophores on the body with 14–16+14–17=29–31 myomeres. Two dark transverse bands on the ventral body surface and one melanophore on the lower margin of the eye in newly hatched larvae were diagnostic. Additionally, a cement organ for adhering to objects was present on the forehead of yolk sac larvae mm BL. The yolk was completely absorbed at 3.5mm BL. Notochord flexion was initiated at 5.0mm BL and finished at 6.0mm BL. Aggregate numbers of all fin rays were completed at 9.2mm BL. Squamation was initiated on the caudal peduncle at 8.0mm BL and completed at 10mm BL. The eggs of C. dadiburjori resembled those of the closely related species Devario malabaricus and Danio rerio. The larvae and juveniles of C. dadiburjori were also similar to those of the latter species in general morphology, especially the presence of body melanophores in newly hatched individuals and a distinctive lateral streak on the head during the period from yolk sac to postflexion larvae. However, early yolk sac larvae of C. dadiburjori were more similar to those of Devario malabaricus than Danio rerio in having a cement organ on the forehead. Larvae and juveniles of C. dadiburjori differed from those of the latter two species in pigmentation on the ventral body surface at hatching and around the mouth during the period from preflexion to early postflexion larvae and in having a dark lateral streak or band on the body in postflexion larvae and juveniles.
Embryonic, larval, and juvenile development of a Taiwanese cyprinid fish, Candidia barbatus, is described from laboratory-reared specimens. The eggs, measuring 1.8–2.1 mm in diameter, were demersal, almost spherical
in shape, transparent and unpigmented, with a pale yellow yolk and no oil globule. Hatching occurred 56–69 h after fertilization,
the newly hatched larvae measuring 4.9–5.3 mm in body length (BL) with 25–26 + 13–14 = 39–40 myomeres. The yolk was completely
absorbed at 7.6 mm BL. Notochord flexion was initiated at 6.8 mm BL and finished at 7.6 mm BL. Aggregate numbers of all fin
rays were completed at 12 mm BL. Barbels on the upper jaw appeared near the corner of the mouth at 17 mm BL. Eggs of the species
closely resembled those of its related cyprinid genera, Opsariichthys and Zacco. Larvae and juveniles of C. barbatus were similar to those of O. uncirostris subspp., Z. platypus, and Z. pachycephalus, but differed from the latter in the process of disappearance of the adipose finfold (postflexion larval stage), barbels
on upper jaw (juvenile stage), and pigmentation on the lateral body surface (postflexion larval and juvenile stages). Although
C. barbatus also differed from the Z. temminckii species' group [Z. temminckii and Zacco sp. (sensu Hosoya, 2002)] in having barbels, larvae and juveniles of the former showed more similarity to the latter species group than
to O. uncirostris subspp., Z. platypus, and Z. pachycephalus, from the aspect of head and body pigmentation.
Key words Cyprinidae-Candidia barbatus-Egg-Larva-Juvenile
Embryonic, larval, and juvenile development of a small cyprinid species, Tanichthys albonubes, is described from laboratory-reared specimens. The eggs, measuring 1.0–1.2 mm in diameter, were demersal, almost spherical
in shape, transparent and unpigmented, with a pale yolk without oil globules. Hatching occurred 45–53 h after fertilization
at 25.5°–26.9°C. The newly hatched larvae, measuring 2.2–2.6 mm in body length (BL), had melanophores on the head and body.
In particular, a dark vertical streak occurring posterior to the otic capsule and melanophores above the eyes were distinctive.
The yolk was completely absorbed at 3.4 mm BL. Notochord flexion was initiated at 5.0 mm BL and finished at 6.0 mm BL. Aggregate
numbers of all fin rays were completed at 11 mm BL. Squamation was initiated at 8.4 mm BL and completed at 13 mm BL. Although
the eggs of T. albonubes resembled those of other small danionin species, including Aphyocypris chinensis, Chela dadiburjori, Danio rerio, Devario malabaricus, Gobiocypris rarus, Hemigrammocypris rasborella, and Horadandia atukorali, they differed from those of A. chinensis, C. dadiburjori, G. rarus, and Horadandia atukorali in having a wider perivitelline space. The larvae and juveniles of T. albonubes were similar to those of the aforementioned seven species plus Danio albolineatus, Danio kerri, and Devario sp. (cf. D. aequipinnatus) in general morphology. However, the early life stage morphology of T. albonubes differed from them in having a dark vertical streak posterior to the otic capsule and melanophores above the eyes in the
yolk sac larval stage, and a dark lateral streak with an unpigmented area just above the former on the body, a dark blotch
on the caudal fin, and reddish dorsal, anal, and caudal fins during the postflexion larval and juvenile stages.
Common carp Cyprinus carpio L. were reared a constant temperature of 20 degrees C from the larval (7 mm total length) to the juvenile (80 mm) stage. Body morphology and white muscle mass distribution were measured. Fast-start escape responses were recorded using high-speed cinematography from which the velocities, accelerations and hydrodynamic power requirements were estimated. All three measures of fast-start performance increased during development. White muscle contraction regimes were calculated from changes in body shape during the fast-starts and used to predict the muscle force and power production for all longitudinal positions along the body. Scaling arguments predicted that increases in body length would constrain the fish to bend less rapidly because the cross-sectional muscle area, and hence force production, does not increase at the same rate as the inertial mass that resists bending. As predicted, the increases in body length resulted in decreases in muscle shortening velocity, and this coincided with increases in both the force and power produced by the muscles. The hydrodynamic efficiency, which relates the mechanical power produced by the muscles to the inertial power requirements in the direction of travel, showed no significant change during ontogeny. The increasing hydrodynamic power requirements were thus met by increases in the power available from the muscles. The majority of the increases in fast-start swimming performance during ontogeny can be explained by size-dependent increases in muscle power output. For all sizes, there was a decrease in muscle-mass-specific power output and an increase in muscle stress in a posterior direction along the body due to systematic variations in fibre strain. These changing strain regimes result in the central muscle bulk producing the majority of the power requirements during the fast-start, and this power is transmitted to the tail region of the fish and ultimately to the water via muscle in the caudal myotomes.
The early growth, yolk and oil globule resorption, early morphological and behavioral development, and initial feeding of hatchery-raised Lates calcarifer were studied, Based on the developmental events and the energy thereby utilized, the early life history of this species can be broken down into the following five phases: 1) rapid early growth due to rapid yolk resorption (from hatching to about 15 hr after hatching (TAH); 2) morphological differentiation and slow growth based on energy from yolk (to about 50 h TAH when the yolk is exhausted); 3) slow growth with initiation of feeding and swimming activities, based on energy from oil globule and from exogenous food (to about 110 h TAH); 4) accelerated growth and effective feeding and swimming based on the same two sources of energy as in the preceding stage (up to about 120-140 h TAH when the oil globule is exhausted); and 5) accelerated growth, effective feeding and swimming and further development based solely on exogenous energy (beyond 140 h TAH). © 1986, The Japanese Society of Fisheries Science. All rights reserved.
: The development of embryos, larvae and juveniles of the Ryukyu-ayu, Plecoglossus altivelisryukyuensis are described based on laboratory-reared specimens.The eggs were spherical, 0.98–1.18 mm (mean 1.06 mm)in diameter with an adherent membrane. The incubation period after fertilizationwas approximately 155 h at a water temperature of 19.7–22.0°C(mean 20.7°C). Newly hatched larvae were 5.0–5.9 mm(mean 5.5 mm) in body length (BL) with 59–62 myotomes.Within 5 days after hatching, the larvae had attained 6.4–8.2 mm(mean 7.8 mm) BL and had completely consumed their yolk.Notochord flexion began at 13.7 mm BL and was completedby 16.3 mm BL. The rudimental dorsal, anal, pelvic andadipose fins appeared at 14.7, 16.3, 21.8 and 21.8 mm BL, respectively.All fin rays reached the same fixed number of adult fish at about28 mm BL. The comb-like teeth began to form at approximately30 mm BL and were fully developed at about 40–50 mm BL.The proportions of P. a. ryukyuensis specimens,which were consistent with adult fish, occurred at approximately40 mm BL.
Experiments on yolk utilization were done with developing herring eggs and larvae from races spawning in the Clyde, North Sea, Atlantic and Baltic. The range of mean dry weight of unfertilized eggs varied from o·126 to o·366 mg in the different races.
The effects of different levels of illumination on common dentex Dentex dentex (L.) larvae have been examined. Illumination affected the relationships between total length and digestive tube length, total length and oil globule volume, and total length and yolk sac. The relationship between total length development and yolk sac utilization in dark and light conditions was found to be significant (P<0.05). However, it was determined that the relationship between digestive tube development and oil globule absorption was not significant (P>0.05). Besides, there is no effect of different light intensities on absorption of yolk sac and oil globule and digestive tube development (P>0.05). In addition, total length development was not significant (P>0.05). Survival rate was found to be not significantly different in dark conditions (P>0.05).
The purpose of the present study was to determine the early growth scheme of hatchery-raised Dicentrarchus labrax larvae through the transition from endogenous to exogenous energy sources, using as the main criterion the body length gained at each stage. The appearance of certain morphological and behavioral characters (body shape, digestive tract differentiation, swimming ability, etc.) in relation to time after hatching (TAH) characterizes the early life history of D. labrax. This period of the sea bass larval life can be divided into the following phases: (i) a phase characterized by seemingly high growth rates and active morphological differentiation and organogenesis based on energy from yolk (0 to 24 h TAH); (ii) a phase characterized by slow growth rates based on energy from yolk (24 to 72 h TAH); (iii) an overlapping phase characterized by slow growth rates and gradual transition from endogenous to exogenous feeding (72 to 120 h TAH); and (iv) a phase characterized by accelerating growth rates and efficient feeding and swimming and further development based on energy from exogenous food (from 120 h TAH and beyond).
A b s t r a c t . The larval period in fishes has several definitions, each one deviating slightly from the other. Small discrepancies in the definitions, especially concerning the end of the larval period, can create misunderstandings when applied in practice. I examine the different definitions of a larva, the larval period, including metamorphosis, and the juvenile period. Various criteria used to identify the transition from the larval to juvenile periods are contradictory and refer mostly to the length of the larval period. Ignorance of definitions used to identify the juvenile period has caused many larvae to be regarded as juveniles. I discuss the feasibility of various definitions and the nomenclature on the basis of character evaluation. The occurrence of larval morphological characters, i.e. larval fin fold, differentiation of fins, temporary organs, absence of scale cover, non-adult like body proportions and pigmentation, is examined and some features are compared in eleven species. Irrespective of the different definitions of a larva, there are considerable differences in the schedule and duration of development in certain characters between species and, in terms of duration, also within species owing to environmental conditions. Ontogenetic processes seem to be sufficiently flexible to allow larvae to adapt to their environment, which on the other hand may also shape the phenotype. Determination of the environment in which a larva develops depends not only on the location of the spawning grounds but also on the dispersion of larvae. Dispersal strategies are examined in light of larval morphology and behaviour. After fin differentiation, the transition from larva to juvenile would seem to be best described by the dominant morphological changes in body proportions and coloration, combined with behavioural aspects and habitat changes. I suggest the differences and functional aspects of larvae be examined. The main character of larvae is that they are adapted to make use of resources not normally used by adults.
Malpigmentation is common in hatchery-reared flatfishes, decreasing the market value of whole fish, and increasing the risk of predation for juveniles released to enhance wild stocks. Pigmentation development in flatfishes occurs in two phases. First, during embryonic and larval stages pigment cells differentiate on both sides of the body. Second, at metamorphosis larval melanophores disappear, and adult melanophores differentiate on the ocular but not on the blind side. Malpigmentation seems to result from disruptions of the second phase, and may take the form of albinism on the ocular side or darkening of the blind side. Both types of aberration may be related to aspects of the hatchery environment such as lighting, substratum, and diet. Larval nutrition appears to be a key factor and enrichment of larval diets with fatty acids and Vitamin A can greatly reduce malpigmentation rates; however, levels suffcient to prevent pigmentation defects frequently cause other abnormalities. Two developmental explanations for albinism have been proposed. The first is that differentiation of ocular-side skin follows the normal blind-side pathway and adult melanophores therefore fail to develop on the ocular side. The second hypothesis suggests that dietary deficiencies inhibit retinal development and the resulting visual defects lead to failure of a hormonal signal required for melanophore differentiation. These hypotheses may well be complementary; as yet neither has been thoroughly tested. Definitive tests will require a combination of manipulative techniques such as tissue transplantation and cell culture with nutritional, behavioural and hormonal assays. Such integrative studies will further the understanding both of normal pigmentation development and of the environmental factors that contribute to high rates of albinism in hatchery-reared flatfish.
Ontogeny is a continuous process with temporaryaccelerations. The embryonic period from eggactivation to hatching, and the larval periodthereafter, are considered. Advances in studieson the ontogeny of yolk-feeding Europeanfreshwater and Antarctic marine fish arecompared. New techniques and approaches aresummarized. A method for exact quantificationof the time to any developmental event isrecommended. Four attempts to quantify anindividual's ontogenetic advancement arereviewed, of which Fuiman's ontogenetic indexseems to be the best choice. The relationshipbetween the time to any ontogenetic event(, days) and temperature (t, C)has been quantified by exponential, power law,Blehradek's, Leiner's, and polynomialmodels, whose common weaknesses are that theparameters have no biological meaning, and theydo not allow comparison of temperaturerequirements between species. The ontogeneticrate (V = 1/, days–1) was welldescribed (r2 = 0.92 – 1.00) by a straightline V = a + bt (linear model) in 44 fishspecies over a broad low-mortality temperaturerange. The linear model produces biologicallymeaningful parameters: the temperature ofbiological zero t0 = –a/b, effectivetemperature teff = t –: t0, andeffective day-degrees Deff = (t – t0) = b–1. From t0 andDeff the time to any ontogeneticevent can be computed as: =Deff/(t – t0). In coldwaterspecies low t0 is accompanied by highDeff, whereas in warmwater speciesthe opposite is true. The linear model wasvalidated. Day-degrees (D = t)and physiological day-degrees (PD =t/q, where q is Winberg's temperaturemetabolic correction factor) are based onincorrect assumptions. Their use as temperature-independent measures of ontogeneticadvancement is not advised; by contrast,effective day-degrees (Deff)are temperature-independent and arerecommended. The remaining extrinsic factorsaffecting ontogenetic rate during yolk feedingare: oxygen, salinity, pH, light, dissolvedbiotic compounds, and anthropogenic factors.The main intrinsic factor is egg size, whichpositively affects the time to particularontogenetic steps at inter- and intra-specificlevels. Attempts to quantify the combinedeffects of temperature and salinity, and oftemperature and egg size, are reviewed.
The response of morphological, histological and endocrinological development to exogenous 1-thyroxine (T4) and to water depth during metamorphosis in Atlantic halibut, Hippoglossus hippoglossus, was investigated. Exogenous T4 was given in daily doses of 0.1, 0.05 ppm or a control treatment to halibut larvae at 550 daydegrees (posthatch, premetamorphic) for 14 days. Water depths of 40 cm, 10 cm or 1.5 cm were used to rear halibut larvae from 590 daydegrees for 21 days. Halibut larvae given exogenous T4 at 0.1 ppm had accelerated eye migration relative to MH in fish given 0.05 ppm and in control fish. Pigmentation was correlated with dosage after 14 days. The volume of thyroid tissue was expressed in a dose-dependent manner and exhibited a size-dependency within each treatment. However, the follicles were atypical with reduced colloid, increased lumen and low epithelial cells even in the control group. The results indicate that T4 is a mediator in halibut metamorphosis. In the water depth experiment, only cortisol levels of larvae reared in 1.5 cm water were significantly affected after 21 days, but this was not correlated with metamorphic rate. Hormone profiles, morphological changes and size suggest the existence of a window of opportunity for metamorphosis in halibut extending from about 16 mm and tapering off about 21 mm SL. The pooled hormone profiles indicate the commencement of a hormonal cascade similar to that of other flatfishes during metamorphosis. The results indicate that growth, neural and skeletal transformation, and pigmentation are biochemically separate processes in the metamorphosis of Atlantic halibut.
Eggs and larvae of the winter flounder Pseudopleuronectes americanus Walbaum were hatched and raised in the laboratory under controlled conditions. Biochemical composition was measured during development and found to be similar to that of other species: 65 to 80 percent protein, 15 to 30 percent fat, and 0 to 5 percent carbohydrate. Ash content was 7 to 10 percent of dry weight. The chorion comprised more than half of the weight of an egg and the data suggested that it was possibly a source of nutrition to the developing embryo. The sequence of utilization appeared to be carbohydrate and then protein to hatching, lipid, mixed lipid and protein, the predominantly protein until feeding began. Carbohydrate was accumulated at first feeding and depleted when growth began. Protein and lipid were deposited in approximately constant proportions. Respiration rates of eggs were low, 0.002–0.015 l O2 egg-1 h-1, but rose gradually from fertilization to hatching. Respiration rates of early larvae were from two to eight times that of eggs (0.033–0.131 l O2 larva-1 h-1). Variation in larval respiration rates indicated a three-fold difference in rate according to level of activity. Eggs excreted ammonia at an increasing rate from fertilization to hatching. Larvae excreted ammonia, primary amines, and other unidentified organic nitrogenous substances. Rates of excretion and proportions of excretory products varied with stage of development. Primary amine excretion was variable and a major component in early stages. Ammonia-N excreted was two to 20 times primary amine N excreted. Unidentified substances were the predominant form of N excretion during early feeding. Ammonia accounted for most of the N excreted in older larvae. Early specific growth rates were 2.1 and 5.5%. Net caloric conversion and net and gross nitrogen efficiencies were low in first feeding larvae compared to adult fishes (32.2, 27.7, and 10.7% respectively).
The activities of some digestive enzymes were investigated in Eurasian perch Perca fluviatilis larvae fed live preys during the first month of life. Activities of pancreatic and intestinal enzymes displayed a pattern
characteristic of developing animals. Pancreatic enzymes were efficient at the time of hatching. Trypsin and amylase specific
activities increased during the first developmental days, then decreased even though segmental activities increased continuously
as the larvae grew. The increase of chymotrypsin specific activity was proportional to fish growth. From day21 after hatching
to the end of experiment, the strong increase in the activities of alkaline phosphatase, leucine-aminopeptidaseN, maltase
and γ-glutamyl transpeptidase reflected the development of brush border membranes of enterocytes. This phenomenon occurred
concurrently with a decrease in a cytosolic enzyme, the leucine-alanine peptidase. These opposite patterns indicate a maturation
of enterocytes and the acquisition of an adult mode of digestion within the first month of live.
Methods are described for the successful rearing of northern anchovy larvae (Engraulis mordax
Girard) on cultured foods. Larvae were fed successively on the unarmored dinoflagellate Gymnodinium splendens, the veliger of the gastropod Bulla gouldiana, and nauplii of the brine shrimp Artemia salina. Rearing containers ranging in capacity from 4.5 to 510 l were tested; the smaller ones were found to be most useful for laboratory experimentation. Irreversible starvation occurred when E. mordax were denied food for more than 1.5 days after yolk absorption. Growth rates of larval anchovies fed different diets were compared. Larvae fed G. splendens grew for 1 week at the same rate as animals fed wild plankton, but did not maintain this rate. Laboratory survival of E. mordax larvae on a diet of G. splendens alone, did not differ significantly when veligers supplemented the diet. However, when G. splendens and veligers were fed simultaneously to E. mordax larvae, growth rate was greatly improved, although still not matching the growth attained on a diet of wild plankton. Length (L) versus weight (W) analyses were made for all larvae at all diets. The results showed that weight could be calculated most accurately from length by the relationship log W=3.3237 log L-3.8205, regardless of diet.
Protein metabolism, growth and pigmentation patterns were studied during the process of metamorphosis in the plaice Pleuronectes platessa. Based on the morphological and concurrent metabolic observations the process of metamorphosis could be divided into three different phases: (1) premetamorphosis: from hatching to beginning of eye migration, (2) climaxmetamorphosis: eye migration, and (3) postmetamorphosis: the period immediately after completion of eye migration. During premetamorphosis a gradual increase in DW was observed concomitant with constant concentrations of the nucleic acids RNA and DNA of the larvae. An increasing calcium concentration indicated the beginning of skeleton ossification. Growth during this phase was primarily hyperplastic as indicated by an increase in DNA per larva. Protein catabolism dominated, as indicated by an increase in the carbon to nitrogen ratio concomitant with a decrease in nitrogen per unit DW. During climaxmetamorphosis an initial increase in the concentration of RNA was followed by a decrease in RNA, DNA and protein concentrations and the ratio of RNA to DNA. During postmetamorphosis growth of the larvae was again observed to be hyperplastic. Calcium assimilation reached a plateau depicting complete ossification of the skeleton. Lipid catabolism dominated by the end of the metamorphosis process. Pigmentation appeared to develop in two marked phases. During premetamorphosis larval melanophores and xanthophores dominated the pigmentation pattern. The concentration of these chromatophores was markedly reduced at beginning of the eye migration process. During and immediately after eye migration the concentration of chromatophores increased significantly and the melanophores appeared to be of the adult type.
Spawning in captivity of the red porgy, Pagrus pagrus, was studied at ambient temperature and photoperiod during one breeding season. Spawning lasted 114 days from February 12 to June 5, 1997, within a temperature range of 12.2°C and 18.5°C. The total number of eggs collected during the spawning period was estimated at 77 million of which 14.3% were sinking and 85.7% were buoyant. The percentage of fertilized buoyant eggs was generally high (95–100%). Mean egg diameters ranged from 0.991 to 1.093 mm within a temperature range of 12.2–14.5°C and decreased rapidly with increasing water temperature from 14.5°C to 18.5°C.Larval development, growth, and morphological changes were described from day 0 to day 34. Larvae were reared intensively in 2 m3 tank under a constant photoperiod (18 h light and 6 h dark), and fed initially on rotifers, followed by Artemia nauplii and weaned onto an artificial diet. A green water technique was applied using Nannochloropsis sp. Larvae completed yolk absorption on day 4 after hatching. Feeding began on day 3. Absorption of the oil globule was completed by day 7. Notochord flexion started on day 20 at about 7.0 mm total length (TL). Transformation from larval to juvenile stage occurred between days 23 and 32 after hatching, at a mean TL of 12.7±1.2 mm. Initial swim bladder inflation occurred between day 5 and day 7 after hatching.
Zebra danios, Danio rerio, 3–39 mm long, were studied to quantify ontogenetic changes in routine (spontaneous) swimming. Swimming speeds and mean acceleration rate increased during the larval period with the most rapid changes occurring when fish were between 5 and 15 mm long. At larger sizes, the rate of increase in performance was small. This pattern presumably resulted from morphological changes which also proceeded rapidly in larvae and levelled off towards adulthood. Swimming bouts began with either a large (105°) or a small (3°) turn. Turning angle changed with size apparently due to hydrodynamic conditions, as indexed by Reynolds numbers (Re). Larvae spent 98% of the time in the viscous and intermediate hydrodynamic regimes, of which 90% occurred at an Re of less than 110, and 23% was in the viscous regime (Re<30). Larvae made exclusively small turns when the bout was in the viscous regime (Re<23) and exclusively large ones in the intermediate regime (75<Re<270). Other species show similar rates of travel at lengths between 3 and 7 mm. At larger sizes, the zebra danio, Pacific mackerel, Scomber japonicus, and red sea bream, Pagrus major travel much greater distances per unit time. When their different sizes and rates of development were taken into account, the majority of species eamined showed similar performance levels throughout the larval period. Two species that cover small distances per unit time at a given length (northern anchovy, Engraulis mordax, and Atlantic herring, Clupea harengus) showed performance comparable to that of faster species when their prolonged larval period was taken into account. The implications of these ontogenetic changes in swimming performance for the development of foraging and anti-predator behaviour are discussed.
Early vertebrate embryos pass through a period of remarkable morphological similarity. Possible causes for such similarity of early embryos include modularity, developmental constraints, stabilizing selection, canalization, and exhausted genetic variability. Supposedly, each process creates different patterns of variation and covariation of embryonic traits. We study the patterns of variation of the embryonic phenotype to test ideas about possible evolutionary mechanisms shaping the early embryonic development. We use the zebra fish, Danio rerio, as a model organism and apply repeated measures of individual embryos to study temporal changes of phenotypic variability during development. In particular, we are looking at the embryonic development from 12 hours post fertilization until 27 hours post fertilization. During this time period, the development of individual embryos is documented at hourly intervals. We measured maximum diameter of the eye, length of embryo, number of somites, inclination of somites, and the yolk size (as a maternal effect). The coefficient of variation (CV) was used as a measure of variability that was independent of size. We used a principal component analysis for analysis of morphological integration. The experimental setup kept environment x genotype interactions constant. Nongenetic parental contributions had no significant effects on interindividual variability. Thus all observed phenotypic variation was based on additive genetic variance and error variance. The average CV declined from 14% to 7.7%. The decline of the CV was in particular expressed during 15-19 h post fertilization and occurred in association with multiple correlations among embryonic traits and a relatively high degree of morphological integration. We suggest that internal constraints determine the patterns of variability during early embryonic development of zebra fish.
Preliminary observation related to the culture of Barbus sharpeyi (Bunni)
- M H Al-Nasih
AL-NASIH, M. H. 1992. Preliminary observation related to
the culture of Barbus sharpeyi (Bunni). Journal of Aquaculture in the Tropics 7: 69-78.
The research project on the culture potential of new fish species as alternative for sea bass and sea bream. Ministry of Agriculture and Rural Affairs
- E Buke
- B Ayekin
- H Imam
BUKE, E., AYEKIN, B. & IMAM, H. 2003. (unpublished
data). The research project on the culture potential of new
fish species as alternative for sea bass and sea bream. Ministry of Agriculture and Rural Affairs, General Directorate of Agricultural Research.
Morphological development and growth of chub
- M Calta
CALTA, M. 2000. Morphological development and growth
of chub, Leuciscus cephalus (L. ), larvae. Applied Ichthyology 16: 83-85.
Significance of pigmentation and use in aquaculture
- I Diler
- K Dilek
DILER, I. & DILEK, K. 2002. Significance of pigmentation
and use in aquaculture. Turkish Journal of Fishery and
Aquatatic Science 2: 97-99.
The cleavage and embryonic phase of gilthead sea bream (Sparus aurata) eggs
- K Firat
- S Saka
- D Coban
FIRAT, K., SAKA, S. & COBAN, D. 2005. The cleavage and
embryonic phase of gilthead sea bream (Sparus aurata)
eggs. Journal of Fisheries & Aquatic Sciences 22: 205-207.
Zebra fish (Danio rerio) embryonic development
- C Kimmel
- W Ballard
- B Ullmann
- T Schmillng
KIMMEL, C., BALLARD, W., ULLMANN, B. & SCHMILLNG,
T. 1995. Zebra fish (Danio rerio) embryonic development. Developmental Dynamics 203: 205-310.
Reproduction of gattan (Barbus xanthopterus), shabbout (Barbus grypus) and Bunni (Barbus sharpeyi) and rearing stocking material of these species
- J Pyka
- R Bartel
- J A Szczerbowski
- P Epler
PYKA, J., BARTEL, R., SZCZERBOWSKI, J. A. & EPLER, P.
2001. Reproduction of gattan (Barbus xanthopterus),
shabbout (Barbus grypus) and Bunni (Barbus sharpeyi)
and rearing stocking material of these species. Archives of
Polish Fisheries 9 (Suppl. 1): 235-246.
Stages of the embryonic development of the Leporinus macrocephalus. Department of Aquaculture, University of Federal of Santa Catarina
- D Reynalte-Tataje
- E Zaniboni-Fihol
- B Muelbert
REYNALTE-TATAJE, D., ZANIBONI-FIHOL, E. & MUELBERT,
B. 2001. Stages of the embryonic development of the Leporinus macrocephalus. Department of Aquaculture, University of Federal of Santa Catarina, Santa Catarina
Brasil. pp. 824 -826.
A study on embryonic development stages of Acanthopterus latus. MSc thesis. Azad University
- A Sarvi-Ghisabadi
SARVI-GHISABADI, A. 2008. A study on embryonic development stages of Acanthopterus latus. MSc thesis. Azad University. Sciences and Research Branch: 4-14.
Age and growth of fish in lakes Tharthar, Razzazah, and Habbaniya. Archives of Polish Fisheries 9
- J Szypula
- P Epler
- R Bartel
- J A Szczerbowki
SZYPULA, J., EPLER, P., BARTEL, R. & SZCZERBOWKI, J. A.
2001. Age and growth of fish in lakes Tharthar, Razzazah, and Habbaniya. Archives of Polish Fisheries 9 (Supll.
1): 185-197.
A study on embryonic development stages of Kutum (Rutilus frisii kutum). MSc thesis. Azad University
- S Behzadi
BEHZADI, S. 1991. A study on embryonic development stages
of Kutum (Rutilus frisii kutum). MSc thesis. Azad University. Tehran Shomal Branch: 15-22.
Early development and gill function in freshwater fish
- M Calta
CALTA, M. 1996. Early development and gill function in
freshwater fish. Ph. D. Thesis. The University of Nottingham. Nottingham. UK.
Ichthyology report on Shadegan Marsh. Southern Iran Aquaculture Fishery Research Centre
- Gh Marammazi
MARAMMAZI, Gh. 1995. Ichthyology report on Shadegan
Marsh. Southern Iran Aquaculture Fishery Research Centre, Ahvaz. 63 pp. [In Persian]
Final report of project of identification of some fresh water fishes of Khuzestan
- N Najafpur
NAJAFPUR, N. 1996. Final report of project of identification
of some fresh water fishes of Khuzestan. Iranian fisheries
research organization 1-96.
Ovos e larvas de peixes de agues doce: desenvolvimento e manual de identificacao. Maringa: Eduem
- K Nakatani
NAKATANI, K. 2001. Ovos e larvas de peixes de agues doce:
desenvolvimento e manual de identificacao. Maringa:
Eduem, 378 p.
Final report of project of biologic study of Barbus grupus and B. sharpeyi. Iranian Fisheries Research Organization
- P M Nikpei
NIKPEI, P. M. 1996. Final report of project of biologic study
of Barbus grupus and B. sharpeyi. Iranian Fisheries
Research Organization: pages 1-10, 52-64.
A Study on embryonic development stages of South Caspian stellate sturgeon (Acipenser stellatus). International Research Institute of Sturgeons
- H Parandavar
PARANDAVAR, H. 2004. A Study on embryonic development
stages of South Caspian stellate sturgeon (Acipenser stellatus). International Research Institute of Sturgeons. IFRO
publications. pp. 111.