池养条件下军曹鱼早期发育阶段的生长和摄食

研究了军曹鱼(Rachycentron canadum)早期阶段的生长和摄食特性。结果表明:1~29日龄间,全长与日龄之间呈指数函数相关:y=3.6922e0.0995x(R=0.9913);体重与日龄间呈指数函数相关:y=0.0002e0.276x(R=0.9830);体重与全长之间为幂函数相关:y=5×10-6x2.786(R=0.9957);口径与日龄的关系为直线函数关系:y=0.1034x-0.0044(R=0.9939)。鱼苗早期阶段的生长速度存在显著性差异。军曹鱼早期鱼苗在3~6日龄时主要摄食原生动物、单轮幼虫和轮虫;7~12日龄时主要摄食桡足类无节幼体;13日龄以后主要摄食桡足类成体。仔、稚鱼阶段,军曹鱼的摄食活动呈现明显的昼夜节律,其饱满度指数均在12时前后出现最高峰,日摄食率分别为57.36%和14.78%。

Growth and Feeding Habits of Rachycentron canadum During Postembryonic Development in Pond

The feeding and growth during the early life of cobia,Rachycentron canadum were studied. The results show that the relationship between the total length and day age of the cobia is expressed as y = 3.692 2 e 0.099 5 x (R = 0.991 3); that of the body weight and day age is y = 0.000 2 e 0.276 x( R = 0.983 0); that of the body weight and total length can be expressed by y = 5×10-6 x 2.786(R = 0.9957);that of the mouth gape and total length is y = 0.103 4 x - 0.004 4 ( R = 0.993 9). There is remarkable difference in the growth speed of the early life. The primary foods of the larval cobia are protozoan, trochophora and rotifer from 3 to 6 days; nauplius of copepod from 7 to 12 days; adult copepods after 13 days. The diurnal feeding rhythm of the Rachycentron canadum in early life history is observed apparently. The peak index of fullness lies at 12:00 in larval stage and juvenile stage. The daily feeding rates are 57.36% and 14.78% in larval and juvenile stage.