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Catfish (Siluriformes) are important species for aquaculture worldwide, with an annual production in 2018 of ca. 6 million t. This review focuses on reassessing larval development, first feeding, and early rearing practices of the most important farmed catfish species, along with some candidate species for aquaculture diversification: Pangasianodon hypophthalmus (Pangasiidae), Clarias gariepinus (Clariidae), Ictalurus punctatus (Ictaluridae), Pseudoplatystoma spp. (Pimelodidae), Heteropneustes fossilis (Heteropneustidae), Rhamdia quelen (Heptapteridae), Ompok bimaculatus (Siluridae), and Lophiosilurus alexandri (Pseudopimelodidade). These species are initially reared indoors from one day to two weeks and are then transferred to fertilised outdoor ponds where they either feed on natural zooplankton or compound feeds. With the exception of C. gariepinus, I. punctatus, R. quelen and P. hypophthalmus, consistent and reliable fry production is a bottleneck that limits the expansion of farming of other species, such as Pseudoplatystoma spp., H. fossilis, O. bimaculatus, and L. alexandri. Rearing systems (extensive, semi-extensive, intensive) and feeding protocols vary with species and geographical regions. Cannibalism and size heterogeneity are common, and these features create problems for larval and fry rearing of catfish species. Information about their nutritional requirements is required for the formulation of compound feeds that can guarantee high survival and good growth of catfish fries. However, such knowledge for most species is scarce, although some data are available for I. punctatus. Further genomic resources might allow fine-tuning rearing success. This review describes some successes in this field, and also highlights gaps in knowledge to guide future research that can promote the development of catfish aquaculture.

Trabajo realizado por investigadores de la Red LARVAplus y colaboradores. El mismo constituye un compendio sobre la información disponible de gran parte de especies autóctonas de peces que se cultivan en Iberoamérica, información que tiene como objetivo servir como referencia para instituciones públicas, universidades, centros de investigación, emprendedores y sector productivo para establecer sus programas y planes de desarrollo acuícola.

Pseudoplatystoma punctifer is a highly appreciated fish species native to the Amazon basin, whose commercial farming has been hampered by low survival during early life stages due to the high incidence of cannibalism and the low acceptability of compound diets at weaning. Dietary DHA is known to promote digestive system development and maturation and growth, whereas its deficiency induces stress. The aim of this study was to evaluate the effect of dietary DHA supplementation on the incidence of cannibalism, digestive physiology, and growth performance during the early life stages of P. punctifer to improve current feeding protocols. Four dietary treatments were generated using a commercial enrichment product with high DHA content. Fish larvae were fed non-enriched or enriched Artemia from 4 to 15 days post fertilization (dpf) and fed a non-enriched or enriched compound diet from 15 to 26 dpf, coinciding with the start of the juvenile stage. Growth, survival, incidence of cannibalism, proximate and fatty acid composition, histology of the intestine and liver, and quantitative gene expression of the main digestive enzymes (amy, try, ctr, pga, pla2, and lpl) were analyzed in the different dietary groups at the end of each feeding period. Results showed that dietary DHA supplementation influenced P. punctifer in a developmental stage-dependent manner. In particular, DHA-enriched Artemia provided during the larval stage contributed to reduce the incidence of cannibalism and improved survival at the early juvenile stage, while enriching the compound diet improved growth. The expression level of genes involved in protein and carbohydrate digestion (ctr, amy) was higher in groups fed enriched Artemia despite that both enriched and non-enriched Artemia displayed similar proximate composition, suggesting that different dietary fatty acid profiles may modulate the expression of these digestive enzyme precursors. The group transitioning from enriched Artemia to non-enriched com

Trabajo realizado por investigadores de la Red LARVAplus y colaboradores. El mismo constituye un compendio sobre la información disponible de gran parte de especies autóctonas de peces que se cultivan en Iberoamérica, información que tiene como objetivo servir como referencia para instituciones públicas, universidades, centros de investigación, emprendedores y sector productivo para establecer sus programas y planes de desarrollo acuícola.

Pseudoplatystoma punctifer is a highly appreciated fish species native to the Amazon basin, whose commercial farming has been hampered by low survival during early life stages due to the high incidence of cannibalism and the low acceptability of compound diets at weaning. Dietary DHA is known to promote digestive system development and maturation and growth, whereas its deficiency induces stress. The aim of this study was to evaluate the effect of dietary DHA supplementation on the incidence of cannibalism, digestive physiology, and growth performance during the early life stages of P. punctifer to improve current feeding protocols. Four dietary treatments were generated using a commercial enrichment product with high DHA content. Fish larvae were fed non-enriched or enriched Artemia from 4 to 15 days post fertilization (dpf) and fed a non-enriched or enriched compound diet from 15 to 26 dpf, coinciding with the start of the juvenile stage. Growth, survival, incidence of cannibalism, proximate and fatty acid composition, histology of the intestine and liver, and quantitative gene expression of the main digestive enzymes (amy, try, ctr, pga, pla2, and lpl) were analyzed in the different dietary groups at the end of each feeding period. Results showed that dietary DHA supplementation influenced P. punctifer in a developmental stage-dependent manner. In particular, DHA-enriched Artemia provided during the larval stage contributed to reduce the incidence of cannibalism and improved survival at the early juvenile stage, while enriching the compound diet improved growth. The expression level of genes involved in protein and carbohydrate digestion (ctr, amy) was higher in groups fed enriched Artemia despite that both enriched and non-enriched Artemia displayed similar proximate composition, suggesting that different dietary fatty acid profiles may modulate the expression of these digestive enzyme precursors. The group transitioning from enriched Artemia to non-enriched com

Catfish (Siluriformes) are important species for aquaculture worldwide, with an annual production in 2018 of ca. 6 million t. This review focuses on reassessing larval development, first feeding, and early rearing practices of the most important farmed catfish species, along with some candidate species for aquaculture diversification: Pangasianodon hypophthalmus (Pangasiidae), Clarias gariepinus (Clariidae), Ictalurus punctatus (Ictaluridae), Pseudoplatystoma spp. (Pimelodidae), Heteropneustes fossilis (Heteropneustidae), Rhamdia quelen (Heptapteridae), Ompok bimaculatus (Siluridae), and Lophiosilurus alexandri (Pseudopimelodidade). These species are initially reared indoors from one day to two weeks and are then transferred to fertilised outdoor ponds where they either feed on natural zooplankton or compound feeds. With the exception of C. gariepinus, I. punctatus, R. quelen and P. hypophthalmus, consistent and reliable fry production is a bottleneck that limits the expansion of farming of other species, such as Pseudoplatystoma spp., H. fossilis, O. bimaculatus, and L. alexandri. Rearing systems (extensive, semi-extensive, intensive) and feeding protocols vary with species and geographical regions. Cannibalism and size heterogeneity are common, and these features create problems for larval and fry rearing of catfish species. Information about their nutritional requirements is required for the formulation of compound feeds that can guarantee high survival and good growth of catfish fries. However, such knowledge for most species is scarce, although some data are available for I. punctatus. Further genomic resources might allow fine-tuning rearing success. This review describes some successes in this field, and also highlights gaps in knowledge to guide future research that can promote the development of catfish aquaculture.

In European sea bass (Dicentrarchus labrax), as in many other fish species, temperature is known to influence the sex of individuals, with more males produced at relatively high temperatures. It is however unclear to what extent growth or stress are involved in such a process, since temperature is known to influence both growth rate and cortisol production. Here, we designed an experiment aiming at reducing stress and affecting early growth rate. We exposed larvae and juveniles originating from both captive and wild parents to three different treatments: low stocking density, food supplemented with tryptophan and a control. Low stocking density and tryptophan treatment respectively increased and decreased early growth rate. Each treatment influenced the stress response depending on the developmental stage, although no clear pattern regarding the whole-body cortisol concentration was found. During sex differentiation, fish in the low-density treatment exhibited lower expression of gr1, gr2, mr, and crf in the hypothalamus when compared to the control group. Fish fed tryptophan displayed lower crf in the hypothalamus and higher level of serotonin in the telencephalon compared to controls. Overall, fish kept at low density produced significantly more females than both control and fish fed tryptophan. Parents that have been selected for growth for three generations also produced significantly more females than parents of wild origin. Our findings did not allow to detect a clear effect of stress at the group level and rather point out a key role of early sexually dimorphic growth rate in sex determination.

In European sea bass (Dicentrarchus labrax), as in many other fish species, temperature is known to influence the sex of individuals, with more males produced at relatively high temperatures. It is however unclear to what extent growth or stress are involved in such a process, since temperature is known to influence both growth rate and cortisol production. Here, we designed an experiment aiming at reducing stress and affecting early growth rate. We exposed larvae and juveniles originating from both captive and wild parents to three different treatments: low stocking density, food supplemented with tryptophan and a control. Low stocking density and tryptophan treatment respectively increased and decreased early growth rate. Each treatment influenced the stress response depending on the developmental stage, although no clear pattern regarding the whole-body cortisol concentration was found. During sex differentiation, fish in the low-density treatment exhibited lower expression of gr1, gr2, mr, and crf in the hypothalamus when compared to the control group. Fish fed tryptophan displayed lower crf in the hypothalamus and higher level of serotonin in the telencephalon compared to controls. Overall, fish kept at low density produced significantly more females than both control and fish fed tryptophan. Parents that have been selected for growth for three generations also produced significantly more females than parents of wild origin. Our findings did not allow to detect a clear effect of stress at the group level and rather point out a key role of early sexually dimorphic growth rate in sex determination.

Pseudoplatystoma punctifer is an Amazonian catfish highly appreciated for its high flesh quality, size, and commercial value. Its aquaculture is pursued to satisfy the demands of an increasing population in the region. However, knowledge of the nutritional needs during the early life stages is necessary for improving growth and reducing the incidence of cannibalism, factors that limit the success of its commercial farming. This study aimed at evaluating the influence of four diets containing different protein and lipid levels (30:15, 30:10, 45:15, or 45:10 in %) in the digestive physiology and performance of early juveniles. The results showed that the dietary protein:lipid as well as carbohydrate levels and ratios influenced differently the whole-body proximate composition, the digestive physiology and development, and hence growth and survival. The 45:15 diet promoted the best growth, survival, and the most rapid development of the digestive system, as shown at histological (higher number of hepatocytes, goblet cells in the anterior intestine and enterocytes in all intestinal portions, and longer folds in the posterior intestine), molecular (highest amylase, lipoprotein lipase, phospholipase, trypsinogen, and pepsinogen gene expression), and biochemical (highest lipase and pepsin activities and higher alkaline phosphatase:leucine alanine peptidase activity ratio) levels. Lipids were favored over carbohydrates as source of energy, with lipids promoting a protein-sparing effect at adequate energy:protein ratio. Carbohydrate content higher than 25% was excessive for this species, leading to unbalanced lipid metabolism and fat deposition in the liver.

Skin pigmentation pattern is a species-specific characteristic that depends on the number and the spatial combination of several types of chromatophores. This feature can change during life, for example in the metamorphosis or reproductive cycle, or as a response to biotic and/or abiotic environmental cues (nutrition, UV incidence, surrounding luminosity, and social interactions). Fish skin pigmentation is one of the most important quality criteria dictating the market value of both aquaculture and ornamental species because it serves as an external signal to infer its welfare and the culture conditions used. For that reason, several studies have been conducted aiming to understand the mechanisms underlying fish pigmentation as well as the influence exerted by rearing conditions. In this context, the present review focuses on the current knowledge on endocrine regulation of fish pigmentation as well as on the aquaculture conditions affecting skin coloration. Available information on Iberoamerican fish species cultured is presented.

In European sea bass (Dicentrarchus labrax), as in many other fish species, temperature is known to influence the sex of individuals, with more males produced at relatively high temperatures. It is however unclear to what extent growth or stress are involved in such a process, since temperature is known to influence both growth rate and cortisol production. Here, we designed an experiment aiming at reducing stress and affecting early growth rate. We exposed larvae and juveniles originating from both captive and wild parents to three different treatments: low stocking density, food supplemented with tryptophan and a control. Low stocking density and tryptophan treatment respectively increased and decreased early growth rate. Each treatment influenced the stress response depending on the developmental stage, although no clear pattern regarding the whole-body cortisol concentration was found. During sex differentiation, fish in the low-density treatment exhibited lower expression of gr1, gr2, mr, and crf in the hypothalamus when compared to the control group. Fish fed tryptophan displayed lower crf in the hypothalamus and higher level of serotonin in the telencephalon compared to controls. Overall, fish kept at low density produced significantly more females than both control and fish fed tryptophan. Parents that have been selected for growth for three generations also produced significantly more females than parents of wild origin. Our findings did not allow to detect a clear effect of stress at the group level and rather point out a key role of early sexually dimorphic growth rate in sex determination.

Pseudoplatystoma punctifer is an Amazonian catfish highly appreciated for its high flesh quality, size, and commercial value. Its aquaculture is pursued to satisfy the demands of an increasing population in the region. However, knowledge of the nutritional needs during the early life stages is necessary for improving growth and reducing the incidence of cannibalism, factors that limit the success of its commercial farming. This study aimed at evaluating the influence of four diets containing different protein and lipid levels (30:15, 30:10, 45:15, or 45:10 in %) in the digestive physiology and performance of early juveniles. The results showed that the dietary protein:lipid as well as carbohydrate levels and ratios influenced differently the whole-body proximate composition, the digestive physiology and development, and hence growth and survival. The 45:15 diet promoted the best growth, survival, and the most rapid development of the digestive system, as shown at histological (higher number of hepatocytes, goblet cells in the anterior intestine and enterocytes in all intestinal portions, and longer folds in the posterior intestine), molecular (highest amylase, lipoprotein lipase, phospholipase, trypsinogen, and pepsinogen gene expression), and biochemical (highest lipase and pepsin activities and higher alkaline phosphatase:leucine alanine peptidase activity ratio) levels. Lipids were favored over carbohydrates as source of energy, with lipids promoting a protein-sparing effect at adequate energy:protein ratio. Carbohydrate content higher than 25% was excessive for this species, leading to unbalanced lipid metabolism and fat deposition in the liver.

Skin pigmentation pattern is a species-specific characteristic that depends on the number and the spatial combination of several types of chromatophores. This feature can change during life, for example in the metamorphosis or reproductive cycle, or as a response to biotic and/or abiotic environmental cues (nutrition, UV incidence, surrounding luminosity, and social interactions). Fish skin pigmentation is one of the most important quality criteria dictating the market value of both aquaculture and ornamental species because it serves as an external signal to infer its welfare and the culture conditions used. For that reason, several studies have been conducted aiming to understand the mechanisms underlying fish pigmentation as well as the influence exerted by rearing conditions. In this context, the present review focuses on the current knowledge on endocrine regulation of fish pigmentation as well as on the aquaculture conditions affecting skin coloration. Available information on Iberoamerican fish species cultured is presented.

In European sea bass (Dicentrarchus labrax), as in many other fish species, temperature is known to influence the sex of individuals, with more males produced at relatively high temperatures. It is however unclear to what extent growth or stress are involved in such a process, since temperature is known to influence both growth rate and cortisol production. Here, we designed an experiment aiming at reducing stress and affecting early growth rate. We exposed larvae and juveniles originating from both captive and wild parents to three different treatments: low stocking density, food supplemented with tryptophan and a control. Low stocking density and tryptophan treatment respectively increased and decreased early growth rate. Each treatment influenced the stress response depending on the developmental stage, although no clear pattern regarding the whole-body cortisol concentration was found. During sex differentiation, fish in the low-density treatment exhibited lower expression of gr1, gr2, mr, and crf in the hypothalamus when compared to the control group. Fish fed tryptophan displayed lower crf in the hypothalamus and higher level of serotonin in the telencephalon compared to controls. Overall, fish kept at low density produced significantly more females than both control and fish fed tryptophan. Parents that have been selected for growth for three generations also produced significantly more females than parents of wild origin. Our findings did not allow to detect a clear effect of stress at the group level and rather point out a key role of early sexually dimorphic growth rate in sex determination.

Pseudoplatystoma punctifer is an Amazonian catfish highly appreciated for its high flesh quality, size, and commercial value. Its aquaculture is pursued to satisfy the demands of an increasing population in the region. However, knowledge of the nutritional needs during the early life stages is necessary for improving growth and reducing the incidence of cannibalism, factors that limit the success of its commercial farming. This study aimed at evaluating the influence of four diets containing different protein and lipid levels (30:15, 30:10, 45:15, or 45:10 in %) in the digestive physiology and performance of early juveniles. The results showed that the dietary protein:lipid as well as carbohydrate levels and ratios influenced differently the whole-body proximate composition, the digestive physiology and development, and hence growth and survival. The 45:15 diet promoted the best growth, survival, and the most rapid development of the digestive system, as shown at histological (higher number of hepatocytes, goblet cells in the anterior intestine and enterocytes in all intestinal portions, and longer folds in the posterior intestine), molecular (highest amylase, lipoprotein lipase, phospholipase, trypsinogen, and pepsinogen gene expression), and biochemical (highest lipase and pepsin activities and higher alkaline phosphatase:leucine alanine peptidase activity ratio) levels. Lipids were favored over carbohydrates as source of energy, with lipids promoting a protein-sparing effect at adequate energy:protein ratio. Carbohydrate content higher than 25% was excessive for this species, leading to unbalanced lipid metabolism and fat deposition in the liver.

Skin pigmentation pattern is a species-specific characteristic that depends on the number and the spatial combination of several types of chromatophores. This feature can change during life, for example in the metamorphosis or reproductive cycle, or as a response to biotic and/or abiotic environmental cues (nutrition, UV incidence, surrounding luminosity, and social interactions). Fish skin pigmentation is one of the most important quality criteria dictating the market value of both aquaculture and ornamental species because it serves as an external signal to infer its welfare and the culture conditions used. For that reason, several studies have been conducted aiming to understand the mechanisms underlying fish pigmentation as well as the influence exerted by rearing conditions. In this context, the present review focuses on the current knowledge on endocrine regulation of fish pigmentation as well as on the aquaculture conditions affecting skin coloration. Available information on Iberoamerican fish species cultured is presented.

In European sea bass (Dicentrarchus labrax), as in many other fish species, temperature is known to influence the sex of individuals, with more males produced at relatively high temperatures. It is however unclear to what extent growth or stress are involved in such a process, since temperature is known to influence both growth rate and cortisol production. Here, we designed an experiment aiming at reducing stress and affecting early growth rate. We exposed larvae and juveniles originating from both captive and wild parents to three different treatments: low stocking density, food supplemented with tryptophan and a control. Low stocking density and tryptophan treatment respectively increased and decreased early growth rate. Each treatment influenced the stress response depending on the developmental stage, although no clear pattern regarding the whole-body cortisol concentration was found. During sex differentiation, fish in the low-density treatment exhibited lower expression of gr1, gr2, mr, and crf in the hypothalamus when compared to the control group. Fish fed tryptophan displayed lower crf in the hypothalamus and higher level of serotonin in the telencephalon compared to controls. Overall, fish kept at low density produced significantly more females than both control and fish fed tryptophan. Parents that have been selected for growth for three generations also produced significantly more females than parents of wild origin. Our findings did not allow to detect a clear effect of stress at the group level and rather point out a key role of early sexually dimorphic growth rate in sex determination.

The aim of the study was to evaluate the functional ontogeny of the digestive system of Pseudoplatystoma punctifer through the analysis of the activity of the main intestinal (alkaline phosphatase, aminopeptidase N, maltase and leucine-alanine peptidase), pancreatic (trypsin, chymotrypsin, total alkaline proteases, bile-salt activated lipase and amylase) and gastric (pepsin) enzymes. Larvae were raised in triplicate in a recirculation system from 4 to 27 days post fertilization (dpf) at an initial density of 90 larvae L−1, 27.8 ± 0.7 °C and 0 L: 24D photoperiod. Larvae were fed from 4 to 17 dpf with Artemia nauplii and weaned onto an experimentally formulated feed (crude protein content ~ 45%; crude fat content ~ 10%; crude carbohydrate ~ 8%) within 3 days, then continued with the same diet until the end of the trial. P. punctifer showed an exponential growth pattern with two different growth rates: a slower one from hatching to 12 dpf followed by a faster one from 12 to 27 dpf. The specific and total activities of the pancreatic and intestinal enzymes were detected from hatching. The digestive system was functional at 12 dpf, indicating the transition from the larval to the juvenile stage (alkaline to acid digestion). Therefore individuals could be weaned from that day onwards. The variations observed in the enzymatic activity from 17 dpf reflected the adaptation of the enzymatic machinery to the new diet supplied. P. punctifer larvae showed a fast digestive system development with an enzymatic profile typical of a tropical and carnivorous species.

The aim of the study was to evaluate the functional ontogeny of the digestive system of Pseudoplatystoma punctifer through the analysis of the activity of the main intestinal (alkaline phosphatase, aminopeptidase N, maltase and leucine-alanine peptidase), pancreatic (trypsin, chymotrypsin, total alkaline proteases, bile-salt activated lipase and amylase) and gastric (pepsin) enzymes. Larvae were raised in triplicate in a recirculation system from 4 to 27 days post fertilization (dpf) at an initial density of 90 larvae L−1, 27.8 ± 0.7 °C and 0 L: 24D photoperiod. Larvae were fed from 4 to 17 dpf with Artemia nauplii and weaned onto an experimentally formulated feed (crude protein content ~ 45%; crude fat content ~ 10%; crude carbohydrate ~ 8%) within 3 days, then continued with the same diet until the end of the trial. P. punctifer showed an exponential growth pattern with two different growth rates: a slower one from hatching to 12 dpf followed by a faster one from 12 to 27 dpf. The specific and total activities of the pancreatic and intestinal enzymes were detected from hatching. The digestive system was functional at 12 dpf, indicating the transition from the larval to the juvenile stage (alkaline to acid digestion). Therefore individuals could be weaned from that day onwards. The variations observed in the enzymatic activity from 17 dpf reflected the adaptation of the enzymatic machinery to the new diet supplied. P. punctifer larvae showed a fast digestive system development with an enzymatic profile typical of a tropical and carnivorous species.

The aim of the study was to evaluate the functional ontogeny of the digestive system of Pseudoplatystoma punctifer through the analysis of the activity of the main intestinal (alkaline phosphatase, aminopeptidase N, maltase and leucine-alanine peptidase), pancreatic (trypsin, chymotrypsin, total alkaline proteases, bile-salt activated lipase and amylase) and gastric (pepsin) enzymes. Larvae were raised in triplicate in a recirculation system from 4 to 27 days post fertilization (dpf) at an initial density of 90 larvae L−1, 27.8 ± 0.7 °C and 0 L: 24D photoperiod. Larvae were fed from 4 to 17 dpf with Artemia nauplii and weaned onto an experimentally formulated feed (crude protein content ~ 45%; crude fat content ~ 10%; crude carbohydrate ~ 8%) within 3 days, then continued with the same diet until the end of the trial. P. punctifer showed an exponential growth pattern with two different growth rates: a slower one from hatching to 12 dpf followed by a faster one from 12 to 27 dpf. The specific and total activities of the pancreatic and intestinal enzymes were detected from hatching. The digestive system was functional at 12 dpf, indicating the transition from the larval to the juvenile stage (alkaline to acid digestion). Therefore individuals could be weaned from that day onwards. The variations observed in the enzymatic activity from 17 dpf reflected the adaptation of the enzymatic machinery to the new diet supplied. P. punctifer larvae showed a fast digestive system development with an enzymatic profile typical of a tropical and carnivorous species.

The influence of dietary vitamin D-3 (VD3) on survival, growth and morphogenesis during the larval development of European sea bass (Dicentrarchus labrax) was evaluated until 45 days post hatching. Diets contained 4% of the standard vitamin mix (VM) recommended by the National Research Council (NRC) and incorporated 0, 19.2, 38.4, or 140 IU of VD3 per gram of diet to give VD-0, VD-1, VD-2 and VD-3 dietary treatments, respectively. The present study revealed for the first time an impact of dietary VD3 on the sea bass digestive system ontogenesis that consequently conditioned the ossification process and morphogenesis. All dietary VD3 levels were in the "adequate range" based on larval survival. Nevertheless, growth, intestinal maturation and ossification at the end of the larval stage were harmed by the minimum dose of VD3 tested and resulted in the appearance of malformations. VD-2 and VD-3 groups showed satisfactory growth and ossification levels at the end of the larval period. However, results of enzymatic activity and expression of genes involved in the VD3 pathway (bone morphogenetic protein 4, osteocalcin, vitamin D receptors and transient receptor potential cation channel-subfamily V. member 6-) gave evidence of complications during the ossification process as revealed by the high percentage of deformed larvae. A VD3 level of 19.2 IU/g diet appeared necessary to obtain harmonious larval morphogenesis. (C) 2009 Elsevier B.V. All rights reserved.

The influence of dietary vitamin D-3 (VD3) on survival, growth and morphogenesis during the larval development of European sea bass (Dicentrarchus labrax) was evaluated until 45 days post hatching. Diets contained 4% of the standard vitamin mix (VM) recommended by the National Research Council (NRC) and incorporated 0, 19.2, 38.4, or 140 IU of VD3 per gram of diet to give VD-0, VD-1, VD-2 and VD-3 dietary treatments, respectively. The present study revealed for the first time an impact of dietary VD3 on the sea bass digestive system ontogenesis that consequently conditioned the ossification process and morphogenesis. All dietary VD3 levels were in the "adequate range" based on larval survival. Nevertheless, growth, intestinal maturation and ossification at the end of the larval stage were harmed by the minimum dose of VD3 tested and resulted in the appearance of malformations. VD-2 and VD-3 groups showed satisfactory growth and ossification levels at the end of the larval period. However, results of enzymatic activity and expression of genes involved in the VD3 pathway (bone morphogenetic protein 4, osteocalcin, vitamin D receptors and transient receptor potential cation channel-subfamily V. member 6-) gave evidence of complications during the ossification process as revealed by the high percentage of deformed larvae. A VD3 level of 19.2 IU/g diet appeared necessary to obtain harmonious larval morphogenesis. (C) 2009 Elsevier B.V. All rights reserved.

The influence of dietary vitamin D-3 (VD3) on survival, growth and morphogenesis during the larval development of European sea bass (Dicentrarchus labrax) was evaluated until 45 days post hatching. Diets contained 4% of the standard vitamin mix (VM) recommended by the National Research Council (NRC) and incorporated 0, 19.2, 38.4, or 140 IU of VD3 per gram of diet to give VD-0, VD-1, VD-2 and VD-3 dietary treatments, respectively. The present study revealed for the first time an impact of dietary VD3 on the sea bass digestive system ontogenesis that consequently conditioned the ossification process and morphogenesis. All dietary VD3 levels were in the "adequate range" based on larval survival. Nevertheless, growth, intestinal maturation and ossification at the end of the larval stage were harmed by the minimum dose of VD3 tested and resulted in the appearance of malformations. VD-2 and VD-3 groups showed satisfactory growth and ossification levels at the end of the larval period. However, results of enzymatic activity and expression of genes involved in the VD3 pathway (bone morphogenetic protein 4, osteocalcin, vitamin D receptors and transient receptor potential cation channel-subfamily V. member 6-) gave evidence of complications during the ossification process as revealed by the high percentage of deformed larvae. A VD3 level of 19.2 IU/g diet appeared necessary to obtain harmonious larval morphogenesis. (C) 2009 Elsevier B.V. All rights reserved.

The purpose of this study was to examine the impact of graded levels of dietary vitamin A on sea bass larval performances and to determine optimal retinol levels at different larval stages to avoid specific skeletal malformations. Retinol was incorporated into larval feeds at 0, 5,10,15, 25, 35 and 70 mg kg(-1) dry matter (giving rise to RET0, RET5, RET10, RET15, RET25, RET35, RET70 groups, respectively). Analysis of the several types of deformities affecting the skull, vertebral column or fins of the fish were observed depending on experimental groups. On one hand, the incidence of skull malformations affecting the maxillary and premaxillary bones. dentaries, operculum, branchiostegal rays and glossohyal was lower for the RET0 and RET5 groups. On the other hand, the frequency of vertebral (slight fusions and kyphosis of the anterior five vertebrae, over-mineralization and lordosis of the haemal vertebrae, the transformation of the last pre-haemal vertebra into haemal) and fin (deformations of the dorsal and anal pterygiophores, deviations of the related rays, modifications of the anatomy of the caudal supporting elements, partial to complete lack of the pelvic fins) deformities were lower for the RET5-70 groups. In the RET0 group, lower level of Hoxd-9 expression coincided with partial or complete lack of pelvic fin. Our results suggest that the optimal level of retinol for harmonious ontogenesis fluctuate along sea bass larvae development and that inadequate dietary retinol levels alters morphogenesis through the modulation of Hox gene expression, at least for the pelvic fin. (c) 2009 Elsevier B.V. All rights reserved.

It is known in vertebrates that endothelin-1 (ET-1) plays a key role ill morphogenesis whose expression level greatly influences the development of craniofacial malformations. In the Present study, the complete cDNA fragment encoding a precursor of endothelin-1, the preproendothelin-1 (PPET1), was cloned by RACE-PCR from European sea bass. The cDNA encoded a 199 amino acid polypeptide that was composed of the "mature" and "big" ET-1. Relative ET-1 expression levels were investigated in European sea bass larvae fed microparticulate diets containing the standard amount (0.08 g retinol/kg diet: group N) or all excess of retinoic acid which induces skeletal malformations (0.5 g retinol/kg diet: group RA). Real-time reverse transcriptor polymerase chain reaction analysis revealed that PPET1 mRNA levels were sensitively reduced in the RA group during early development (days 10 and 15 post hatching). Regulation of ET-1 gene expression in larvae fed the teratogenic level of vitamin A confirmed the involvement of ET-1 in the molecular mechanism involved in craniofacial deformities. These results suggest that the expression level of ET-1 may be used as a precocious molecular marker to predict malformations during European sea bass development. (c) 2008 Elsevier B.V. All rights reserved.

The purpose of this study was to examine the impact of graded levels of dietary vitamin A on sea bass larval performances and to determine optimal retinol levels at different larval stages to avoid specific skeletal malformations. Retinol was incorporated into larval feeds at 0, 5,10,15, 25, 35 and 70 mg kg(-1) dry matter (giving rise to RET0, RET5, RET10, RET15, RET25, RET35, RET70 groups, respectively). Analysis of the several types of deformities affecting the skull, vertebral column or fins of the fish were observed depending on experimental groups. On one hand, the incidence of skull malformations affecting the maxillary and premaxillary bones. dentaries, operculum, branchiostegal rays and glossohyal was lower for the RET0 and RET5 groups. On the other hand, the frequency of vertebral (slight fusions and kyphosis of the anterior five vertebrae, over-mineralization and lordosis of the haemal vertebrae, the transformation of the last pre-haemal vertebra into haemal) and fin (deformations of the dorsal and anal pterygiophores, deviations of the related rays, modifications of the anatomy of the caudal supporting elements, partial to complete lack of the pelvic fins) deformities were lower for the RET5-70 groups. In the RET0 group, lower level of Hoxd-9 expression coincided with partial or complete lack of pelvic fin. Our results suggest that the optimal level of retinol for harmonious ontogenesis fluctuate along sea bass larvae development and that inadequate dietary retinol levels alters morphogenesis through the modulation of Hox gene expression, at least for the pelvic fin. (c) 2009 Elsevier B.V. All rights reserved.

It is known in vertebrates that endothelin-1 (ET-1) plays a key role ill morphogenesis whose expression level greatly influences the development of craniofacial malformations. In the Present study, the complete cDNA fragment encoding a precursor of endothelin-1, the preproendothelin-1 (PPET1), was cloned by RACE-PCR from European sea bass. The cDNA encoded a 199 amino acid polypeptide that was composed of the "mature" and "big" ET-1. Relative ET-1 expression levels were investigated in European sea bass larvae fed microparticulate diets containing the standard amount (0.08 g retinol/kg diet: group N) or all excess of retinoic acid which induces skeletal malformations (0.5 g retinol/kg diet: group RA). Real-time reverse transcriptor polymerase chain reaction analysis revealed that PPET1 mRNA levels were sensitively reduced in the RA group during early development (days 10 and 15 post hatching). Regulation of ET-1 gene expression in larvae fed the teratogenic level of vitamin A confirmed the involvement of ET-1 in the molecular mechanism involved in craniofacial deformities. These results suggest that the expression level of ET-1 may be used as a precocious molecular marker to predict malformations during European sea bass development. (c) 2008 Elsevier B.V. All rights reserved.

The purpose of this study was to examine the impact of graded levels of dietary vitamin A on sea bass larval performances and to determine optimal retinol levels at different larval stages to avoid specific skeletal malformations. Retinol was incorporated into larval feeds at 0, 5,10,15, 25, 35 and 70 mg kg(-1) dry matter (giving rise to RET0, RET5, RET10, RET15, RET25, RET35, RET70 groups, respectively). Analysis of the several types of deformities affecting the skull, vertebral column or fins of the fish were observed depending on experimental groups. On one hand, the incidence of skull malformations affecting the maxillary and premaxillary bones. dentaries, operculum, branchiostegal rays and glossohyal was lower for the RET0 and RET5 groups. On the other hand, the frequency of vertebral (slight fusions and kyphosis of the anterior five vertebrae, over-mineralization and lordosis of the haemal vertebrae, the transformation of the last pre-haemal vertebra into haemal) and fin (deformations of the dorsal and anal pterygiophores, deviations of the related rays, modifications of the anatomy of the caudal supporting elements, partial to complete lack of the pelvic fins) deformities were lower for the RET5-70 groups. In the RET0 group, lower level of Hoxd-9 expression coincided with partial or complete lack of pelvic fin. Our results suggest that the optimal level of retinol for harmonious ontogenesis fluctuate along sea bass larvae development and that inadequate dietary retinol levels alters morphogenesis through the modulation of Hox gene expression, at least for the pelvic fin. (c) 2009 Elsevier B.V. All rights reserved.

It is known in vertebrates that endothelin-1 (ET-1) plays a key role ill morphogenesis whose expression level greatly influences the development of craniofacial malformations. In the Present study, the complete cDNA fragment encoding a precursor of endothelin-1, the preproendothelin-1 (PPET1), was cloned by RACE-PCR from European sea bass. The cDNA encoded a 199 amino acid polypeptide that was composed of the "mature" and "big" ET-1. Relative ET-1 expression levels were investigated in European sea bass larvae fed microparticulate diets containing the standard amount (0.08 g retinol/kg diet: group N) or all excess of retinoic acid which induces skeletal malformations (0.5 g retinol/kg diet: group RA). Real-time reverse transcriptor polymerase chain reaction analysis revealed that PPET1 mRNA levels were sensitively reduced in the RA group during early development (days 10 and 15 post hatching). Regulation of ET-1 gene expression in larvae fed the teratogenic level of vitamin A confirmed the involvement of ET-1 in the molecular mechanism involved in craniofacial deformities. These results suggest that the expression level of ET-1 may be used as a precocious molecular marker to predict malformations during European sea bass development. (c) 2008 Elsevier B.V. All rights reserved.

During the larval period, marine teleosts undergo very fast growth and dramatic changes in morphology, metabolism, and behavior to accomplish their metamorphosis into juvenile fish. Regulation of gene expression is widely thought to be a key mechanism underlying the management of the biological processes required for harmonious development over this phase of life. To provide an overall analysis of gene expression in the whole body during sea bass larval development, we monitored the expression of 6,626 distinct genes at 10 different points in time between 7 and 43 days post-hatching (dph) by using heterologous hybridization of a rainbow trout cDNA microarray. The differentially expressed genes (n = 485) could be grouped into two categories: genes that were generally up-expressed early, between 7 and 23 dph, and genes up-expressed between 25 and 43 dph. Interestingly, among the genes regulated during the larval period, those related to organogenesis, energy pathways, biosynthesis, and digestion were over-represented compared with total set of analyzed genes. We discuss the quantitative regulation of whole-body contents of these specific transcripts with regard to the ontogenesis and maturation of essential functions that take place over larval development. Our study is the first utilization of a transcriptomic approach in sea bass and reveals dynamic changes in gene expression patterns in relation to marine finfish larval development.

During the larval period, marine teleosts undergo very fast growth and dramatic changes in morphology, metabolism, and behavior to accomplish their metamorphosis into juvenile fish. Regulation of gene expression is widely thought to be a key mechanism underlying the management of the biological processes required for harmonious development over this phase of life. To provide an overall analysis of gene expression in the whole body during sea bass larval development, we monitored the expression of 6,626 distinct genes at 10 different points in time between 7 and 43 days post-hatching (dph) by using heterologous hybridization of a rainbow trout cDNA microarray. The differentially expressed genes (n = 485) could be grouped into two categories: genes that were generally up-expressed early, between 7 and 23 dph, and genes up-expressed between 25 and 43 dph. Interestingly, among the genes regulated during the larval period, those related to organogenesis, energy pathways, biosynthesis, and digestion were over-represented compared with total set of analyzed genes. We discuss the quantitative regulation of whole-body contents of these specific transcripts with regard to the ontogenesis and maturation of essential functions that take place over larval development. Our study is the first utilization of a transcriptomic approach in sea bass and reveals dynamic changes in gene expression patterns in relation to marine finfish larval development.

During the larval period, marine teleosts undergo very fast growth and dramatic changes in morphology, metabolism, and behavior to accomplish their metamorphosis into juvenile fish. Regulation of gene expression is widely thought to be a key mechanism underlying the management of the biological processes required for harmonious development over this phase of life. To provide an overall analysis of gene expression in the whole body during sea bass larval development, we monitored the expression of 6,626 distinct genes at 10 different points in time between 7 and 43 days post-hatching (dph) by using heterologous hybridization of a rainbow trout cDNA microarray. The differentially expressed genes (n = 485) could be grouped into two categories: genes that were generally up-expressed early, between 7 and 23 dph, and genes up-expressed between 25 and 43 dph. Interestingly, among the genes regulated during the larval period, those related to organogenesis, energy pathways, biosynthesis, and digestion were over-represented compared with total set of analyzed genes. We discuss the quantitative regulation of whole-body contents of these specific transcripts with regard to the ontogenesis and maturation of essential functions that take place over larval development. Our study is the first utilization of a transcriptomic approach in sea bass and reveals dynamic changes in gene expression patterns in relation to marine finfish larval development.