Annual cycles of growth rate, feeding rate, food conversion, plasma glucose and plasma lipids in a population of European sea bass (Dicentrarchus labrax
 L.) farmed in floating marine cages

AbstractIn 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.

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Vaccination of European sea bass Dicentrarchus labrax with avirulent Mycobacterium marinum (iipA::kan mutant)

Fish & Shellfish Immunology ◽

10.1016/j.fsi.2019.04.057 ◽

2019 ◽

Vol 90 ◽

pp. 317-327 ◽

Cited By ~ 1

Author(s):

Shay Ravid-Peretz ◽

Angelo Colorni ◽

Galit Sharon ◽

Michal Ucko

Keyword(s):

Dicentrarchus Labrax ◽

Sea Bass ◽

Mycobacterium Marinum ◽

European Sea Bass

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Understanding the Interaction Effects between Dietary Lipid Content and Rearing Temperature on Growth Performance, Feed Utilization, and Fat Deposition of Sea Bass (Dicentrarchus labrax)

Animals ◽

10.3390/ani11020392 ◽

2021 ◽

Vol 11 (2) ◽

pp. 392

Author(s):

Lydia Katsika ◽

Mario Huesca Flores ◽

Yannis Kotzamanis ◽

Alicia Estevez ◽

Stavros Chatzifotis

Keyword(s):

Growth Rate ◽

Body Weight ◽

Specific Growth ◽

Dicentrarchus Labrax ◽

Sea Bass ◽

Dietary Lipid ◽

Lipid Levels ◽

Final Body Weight ◽

Temperature Regimes ◽

Fish Group

This study was conducted to elucidate the interaction effects of temperature and dietary lipid levels (2 × 2 factorial experiment) on the growth performance, muscle, and liver composition in adult farmed European sea bass (Dicentrarchus labrax). Two groups of fish (190 g; 60 fish per group) were distributed in 12 tanks in triplicates and kept at two different temperature regimes; one starting at 23 °C and then changed to 17 °C for 61 days, and the other starting at 17 °C and then changed to 23 °C for 39 days. Two commercial diets containing both ~44% crude protein but incorporating different dietary lipid levels, 16.5% (D16) and 20.0% (D20) (dry matter (DM)), were fed to the fish to apparent satiation; the type of diet fed to each fish group remained constant throughout the experiment. Final body weight, weight gain, and specific growth rate were significantly higher for the fish group held at 23 °C compared to the fish group at 17 °C (before the temperature changes), while the dietary fat content did not have any profound effect in both groups. Furthermore, the different temperature regimes did not affect muscle or liver composition, but, on the contrary, dietary lipids affected hepatosomatic, perivisceral fat, and visceral indexes. Feed conversion ratio and specific growth rate were not affected by the dietary lipid level. An interaction of temperature and dietary lipid content was observed in daily feed consumption (DFC) and final body weight (FBW).

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