两种无鳞高原鳅年龄鉴定方法探讨

分析了采自新疆克孜河174尾长身高原鳅(Triplophysa teunis)和258尾叶尔羌高原鳅(T.yarkandensis)的矢耳石及部分个体的背鳍条(n=11和12)、主鳃盖骨(n=20和25)和脊椎骨(n=38和45)的轮纹标志,探讨了用其鉴定年龄的可行性。结果显示,背鳍条磨片和主鳃盖骨均无明显可辨的年轮标志。小个体长身高原鳅的脊椎骨磨片年轮比较模糊,总的判别能力及鉴定吻合率分别为52.63%和70.00%。叶尔羌高原鳅脊椎骨磨片的年龄判别能力为93.33%,但5龄以下个体存在轮纹的断裂、分支和聚合现象,鉴定吻合率为78.57%。所有矢耳石磨片均有日生长增长、生长阻断和年轮等生长标记,年轮由宽而不透明的暗带和窄而透明的亮带组成。174尾长身高原鳅中有171尾矢耳石磨片能观察到年轮特征,判别能力及鉴定吻合率高达98.28%和94.74%。258尾叶尔羌高原鳅有244尾矢耳石磨片能观察到年轮特征,判别能力及鉴定吻合率也高达94.57%和93.44%。两位鉴定者对同一尾鱼的脊椎骨磨片和矢耳石磨片进行年龄计数,长身高原鳅的总吻合率分别为75.00%和80.00%,叶尔羌高原鳅的总吻合率分别为73.81%和83.33%,两鉴定者间无显著性差异(P0.05)。研究表明,矢耳石是两种无鳞高原鳅类最好的年龄鉴定材料,脊椎骨可作为高龄个体的辅助鉴定材料。

Discussion on Age Determination Methods for Two Esquamate Triplophysa Fishes

This paper analyzed the annuli characteristics of sagitta,part of dorsal fin ray(n=11 and 12),opercular (n=20 and 25) and vertebra(n=38 and 45) of 174 Triplophysa teunis samples and 258 T.yarkandensis samples collected from Kezi River in southern Xinjiang in May 2008,and assessed their usage in age determination.The results showed that dorsal fin ray and opercular were unsuitable for ageing,mostly because of the pseudoannuli and ambiguous annuli.The annuli characteristics on vertebra of T.teunis with body l...