Effects of the Ampfitude and Frequency of Salinity Fluctuation on the Body Composition and Energy Budget of Juvenile Tongue Sole （Cynoglossus semilaevis）

• Published in: 中国海洋大学学报：英文版 2015 (1), p.127-134
• Main Author: Sachin Onkar KHAIRNAR TIAN Xiangli FANG Ziheng DONG Shuanglin
• Format: Article
• Language: English
• Subjects: 体成分; 半滑舌鳎; 少年; 比生长速率; 波动频率; 盐度; 能量代谢; 预算
• ISSN: 1672-5182; 1993-5021

Effects of the amplitude （±2, ± 4, ± 6, and± 8） and frequency （2, 4, and 8 d） of salinity fluctuation on the body composi- tion and energy budget of juvenile tongue sole （Cynoglossus semilaevis） were investigated in a 64-d experiment. Results showed that the amplitude and frequency of salinity fluctuation had significant interaction and both substantially affected the final weight and specific growth rate of juvenile tongue sole. The tongue sole exhibited better growth in treatments with moderate amplitude and fre- quency of salinity fluctuation （amplitude ±4-6; frequency 4-8 d） than in other treatments and the control. In terms of energy budget, salinity fluctuation strongly affected the proportions of energy components, including those deposited for growth and lost in respira- tion, feces, and excretion. Moderately amplitude and frequency of salinity fluctuationg that favored the growth of tongue sole parti- tioned more energy for growth and less energy for metabolism than the constant and other amplitude and frequency of salinity fluc- tuation. Average energy budget for tongue sole at moderately fluctuating salinity was determined to be 100C （food）= 30.92G （growth） ＋ 10.30F（feces） ＋ 6.77 U（excretion） ＋ 52.01R （respiration）. Energetic advantage at moderately fluctuating salinity, including increased energy intake, high assimilation efficiency, reduced metabolism expenditure, and more energy partitioned into growth, might account for the enhancement of tongue sole growth. Commercial farmers are recommended to rear juvenile tongue sole with moderate salin- ity fluctuations for better growth performance of this species.