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Effects of a superoptimal temperature on aquacultured yellowtail Seriola quinqueradiata

Sotoyama, Yoshinori, Yokoyama, Saichiro, Ishikawa, Manabu, Koshio, Shunsuke, Hashimoto, Hiroshi, Oku, Hiromi, Ando, Tadashi
Fisheries science 2018 v.84 no.6 pp. 1063-1071
Seriola quinqueradiata, amino acids, body composition, body size, body weight, fish, growth performance, hepatosomatic index, juveniles, lipid content, protein content, rearing, water temperature
This study aimed to investigate the effects of a superoptimal temperature on growth, body composition, body size heterogeneity, and relationships among these factors in juvenile yellowtail. Fish (mean body weight = 24 g) were tagged individually and reared for 70 days under two different water temperature regimes [optimal (25 °C) and superoptimal (30 °C)]. After rearing, fish reared at 30 °C showed lower survival, less food, feed and protein utilization, significantly lower growth performance, and a lower hepatosomatic index than fish raised at 25 °C. Variations in body indices among individuals were larger for fish reared at 30 °C than for fish reared at 25 °C. Mean whole body protein content was significantly lower in fish reared at 30 °C than fish reared at 25 °C. In addition, several glucogenic and/or aromatic amino acids were lower in fish reared at 30 °C than in fish reared at 25 °C. Whole body lipid levels tended to be lower in fish with lower body weight reared at 30 °C. These results suggest that fish raised at 30 °C will have lower growth performance, and lower concentrations of specific amino acids. Moreover, heterogeneity in body size and body lipid content is expanded by a superoptimal temperature.