点篮子鱼形态特征及其相关性参数分析

对捕捞自琼海海域的560 ind体重0.3~551.3 g、体长2.3~24.7 cm的野生点篮子鱼外部形态、可量可比性状、可数性状和内部结构进行了研究,分析了形态特征参数间相关关系。结果表明:(1)体呈椭圆形,侧扁;侧线完全,位高,与背缘平行,向后延伸至尾鳍基部;体侧有许多橙黄色斑,背鳍、胸鳍和腹鳍黄色,臀鳍、尾鳍浅灰褐色;背鳍末端下方有一圆斑,为该鱼明显特征。(2)属Y型胃,幽门部肌肉发达,具有4~6个指状粗大的幽门盲囊;消化道、肠道长度分别为体长的2.53±0.36、2.17±0.28倍,肠道长Li与体长Lb的关系式为Li=2.693 1Lb0.903 4(R2=0.879 4)。(3)可量可比性状表明,全长/体长变动范围最小,线性相关性最好,其相关方程为Lt=1.134 5Lb+0.493 6(R2=0.998);体长与体重关系为:W=0.037 6Lb2.893 3(R2=0.991 7);点篮子鱼的b值为2.893 3,小于3,为负异速生长,体长快于体重的增长。(4)分析各形态特征参数与体长关系发现,测定的12个参数均与体长显著相关(P0.01);进而控制体长的影响,分析这12个参数间的偏相关关系,显示与其它参数存在最多偏相关性的是头高,其与除体重外的其它8个参数间均显著相关(P0.01);而尾柄长与其它参数的偏相关性最差,其只与头高、体重显著相关。

Biological characteristics and correlation analysis of morphological characteristics in Siganus guttatus

The external morphology,internal structure and characters of 560 ind Siganus guttatus with body weight ranging from 0.3 to 551.3 g and body length ranging from 2.3 to 24.7 cm were studied through observation,measurement,dissection,data collection and analysis.The relations among morphological characteristic parameters were also carefully investigated.Results demonstrated that:(1) The body shape of S.guttatus was elliptical,compressiform,lateral line complete,parallel to the dorsal brim extending to caudal fin base,with lots of orange spots on the body,and the color of dorsal fin,pectoral fin and pelvic fin was yellow while the color of anal fin and tail fin was light brown,and there was a special circular spot at the end of dorsal fin;(2) the gastric type of S.guttatus was Y-type,with highly developed muscle in pylorus.The number of pyloric caeca was 4 to 6,the ratio between alimentary tract length and body length was 2.53±0.36,the relationship between the intestinal length and body length could be described as Li=2.693 1Lb0.903 4(R2=0.879 4),and the ration between them was 2.17±0.28;(3) the variation between full length and body length was the smallest,the linear correlation was the best and could be described as Lt=1.134 5Lb+0.493 6(R2=0.998).The relationship between body length and body weight was W=0.037 6Lb2.893 3(R2=0.991 7).The value of b was 2.893 3,close to 3,which meant that the growth type of S.guttatus was negative allometric,but it was close to isomeric growth;(4) Head height had the partial correlations with other 8 parameters except body weight when the body length was maintained.The caudal peduncle length had a significant partial correlation with head height and body weight while it was not the case with other parameters.