基于矢耳石形态的平鲉属（Sebastes）鱼类鉴别及研究方法比较

摘要

The sagittae morphological characteristics of three species Sebastes hubbsi ,S.nigricans and S.schlegelii from Jiaozhou Bay,Qingdao,were analyzed to test the hypothesis that the three Sebastes species could be identified by their sagittae morphology and to find out which method was more appropriate.Eight otolith shape indices and 37 elliptical Fourier coefficients (eFcs)were analyzed,and results showed that the difference in the sagittae mor-phology between S.hubbsi and S.schlegelii were the largest,and those between S.hubbsi and S.nigricans were the least.In the discriminant analyses of the three species,discriminating rates of more than 95% were obtained and they were clearly sorted in scatter plots when using the otolith shape indices,the eFcs,as well as a combination of the two.When applied to the three species of which otolith was 4 to 7 mm and those were more than two years old,the species identification based on the otolith morphology was proved to be feasible:when only using the eFcs, a 100% of discriminating rate was obtained but this method couldn't quickly locate the shape which was tiny in fact but significant difference among the sagittae of the three Sebastes in statistics.Combing otolith shape indices and the eFcs could not only obtain a high classification rate of about 99%,but also identify the differences in the rectan-gularity,form-factor and surface density among the three Sebastes sagittae.The results showed that combing shape indices analysis and elliptical Fourier analysis was the effective method for species discrimination of genus Sebastes and it can find out the differences of the sagittae of the three Sebastes.%分析了青岛胶州湾铠平鲉（Sebastes hubbsi ）、花斑平鲉（Sebastes nigricans ）和许氏平鲉（Sebastes schlegelii ）3种平鲉属鱼类的矢耳石形态特征，探究基于矢耳石形态鉴别 3种鱼类的可行性。以8个耳石形状指标和37个椭圆傅里叶系数进行的单因素方差分析结果基本一致，显示铠平鲉与许氏平鲉的耳石形态差异最大，铠平鲉与花斑平鲉间差异最小。利用耳石形状指标、椭圆傅里叶系数、耳石形状指标与椭圆傅里叶系数相结合的方法，对 3种鱼类的综合判别率均可达95％以上，判别分析散点图可明显将 3种鱼类区分开。耳石长介于4～7 mm 的 3种鱼类小规格组与2龄及以上成鱼组耳石样本的判别结果一致，表明针对不同发育阶段平鲉属鱼类，基于耳石形态的种类鉴别均是可行的；仅使用椭圆傅里叶系数鉴别 3种鱼类时综合判别率虽高达100％，但难以快速定位 3种鱼类耳石形态间，在统计上差异显著而实际上微小的形状差异所在；而使用耳石形状指标和椭圆傅里叶系数联合判别，综合判别率亦高达99％，且能快速找出 3种鱼类耳石在矩形趋近率、形态因子、面密度等的形态差异。研究表明，耳石形状指标和椭圆傅里叶分析联合判别是平鲉属鱼类种类鉴别及耳石形态差异分析的有效手段。