太平洋双色鳗鲡(Anguilla bicolor pacifica)与其它3种鳗鲡的形态差异分析

通过传统形态学数据和框架结构数据相结合,应用方差、聚类、判别和主成分等4种多元分析方法,分析了太平洋双色鳗鲡与日本鳗鲡、美洲鳗鲡和花鳗鲡的形态差异。结果表明:(1)太平洋双色鳗鲡背鳍前端与臀鳍前端之间的垂线距离占全长的1.4%,属短鳍型鳗鲡。(2)太平洋双色鳗鲡与其它3种鳗鲡形态差异显著。在可数性状中,太平洋双色鳗鲡的总脊椎骨数显著小于日本鳗鲡,显著大于美洲鳗鲡和花鳗鲡,背鳍前脊椎骨数显著大于其它3种鳗鲡;在可量性状中,太平洋双色鳗鲡的吻长显著小于美洲鳗鲡和花鳗鲡,显著大于日本鳗鲡;在框架结构性状中,太平洋双色鳗鲡有6项性状与其它3种鳗鲡差异显著。(3)太平洋双色鳗鲡的背鳍起点与其它3种鳗鲡相比最靠后,背鳍起点在鳗鲡分类研究中可作为重要的框架结构定位点。本研究可为太平洋双色鳗鲡的合理引进和种质保护提供资料。

MORPHOLOGICAL VARIATIONS ANALYSIS BETWEEN ANGUILLA BICOLOR PACIFICA AND THE OTHER THREE SPECIES OF EELS

Eels are one of most importance culture species in the world aquaculture, which have high nutritional value and delicious flavour. Unfortunately, natural resources of Anguilla japonicus elvers have been declining in recent years; and the supply of the elver is far insufficient to meet the demand from aquaculture. A. bicolor pacifica having high survival rates and excellent growth performance, A. bicolor pacifica has been chosen for aquaculture as the best substitute of A. japonicus. In this paper, traditional morphological data and truss network data were combined to conduct four multivariation analysis methods, including variance analysis, cluster analysis, discriminant analysis, and principal component analysis, to study the morphological variations between A. bicolor pacifica and other three species of eels, including A. japonicus,A. rostrata, and A. marmorata. The results show: (1) As the proportion of the distance between verticals from origin of dorsal fin and anal fin to the total length is 1.4%, A. bicolor pacifica were classified as short-finned eel. (2) Morphological variations between A. bicolor pacifica and other three species of eels are significant. As a meristic character, the number of total vertebra of A. bicolor pacifica was significantly less than that of A. japonicus, but A. rostrata, and A. marmorata were just opposite. Meanwhile, the number of predorsal vertebra of A. bicolor pacifica was significantly greater than those of other three species of eels. The snout length of A. bicolor pacifica was significantly shorter than that of A. rostrata and A. marmorata, but A. japonicus, longer. Among all the truss network characters, six were significantly different between A. bicolor pacifica and other three. (3) The origin point of dorsal fin of A. bicolor pacifica was the rearest among all the eels, which is an important indicator in the classification of eels. This research may provide basic data for reasonable introduction and germ plasma resources protection of A. bicolor pacifica.