鲇鱼形态特征参数与体长关系及变异分析

Phenotypic Variation in Chinese Catfish(Silurus asotus Linnaeus)

本研究对嘉陵江鲇鱼(Silurus asotusL innaeus)形态特征参数测量分析后发现:鲇鱼的头长、体高、臀鳍长、臀鳍高和尾鳍高均随体长的增加呈线性增加;而体重、口裂宽和尾鳍长随体长增加呈指数上升。根据各参数与体长相应拟合方程计算得到去除体长影响后的各参数值,并对各参数值间的相关关系分别进行回归分析,结果表明:头长和口裂宽呈正相关(r=0.703,p<0.001);体高与头长(r=0.366,p<0.05)和口裂宽(r=0.392,p<0.05)也呈正相关;而体重分别与体高(r=0.560,p<0.001)、头长(r=0.532,p<0.001)和口裂宽(r=0.363,p<0.05)呈正相关,与臀鳍长则呈负相关(r=-0.421,p<0.05);依变异系数由大到小排列,各形态特征参数依次分别为:体重(2.01)、臀鳍高(1.64)、头长(1.62)、尾鳍高(1.60)、口裂宽(1.57)、体高(1.28)、尾鳍长(1.27)和臀鳍长(0.87)。

The head length, body height, anal fin length, anal fin height and tail fin height linearly increase with body length in Chinese catfish. The body weight, mouth width and tail fin length increased exponentially with body length. The relative value of head length is positively related with that of mouth width （ r = 0. 703, p 〈 0. 001 ）. The relative value of body weight is positively related with those of body height （ r = 0. 560, p 〈 0.001 ）, head length （ r = 0. 532, p 〈 0. 001 ）, mouth width （ r = 0. 363, p 〈 0.05 ）, and negative related with that of anal fin length （ r = - 0. 421 ,p 〈 0.05 ）. Body height is positively related with head length （ r = 0. 366, p 〈 0. 05 ） and mouth width （ r = 0. 392, p 〈 0.05 ）. The magnitude of variation coefficient of body weight, anal fin height, head length, tail fin height, mouth width, body height, tail fin length and anal fin length are 2.01, 1.64, 1.62, 1.60, 1.57, 1; 28, 1.27 and 0. 87, respectively.