异鳔鳅年龄结构、生长特性与生活史类型

2010年10月至2011年7月在长江上游宜宾至江津江段采集405尾异鳔鳅鮀(Xenophysogobio boulengeri)样本。以耳石作为主要年龄鉴定材料,研究了异鳔鳅鮀的年龄结构和生长特征,采用模糊聚类分析法推断了异鳔鳅鮀的生活史类型。结果表明:长江上游异鳔鳅鮀由4个年龄组组成,其中优势年龄组为1～2龄(占83.70%);体长(L)与体重(W)关系为W=5×10-6L3.294 3(r2=0.941 3,n=405,F=6 040.22,P0.01),体长与耳石半径(R)的关系为L=0.000 8R2-0.168 4R+42.504(r2=0.836 5,n=399,F=399.20,P0.01);von Bertalanffy方程描述的生长方程为Lt=179.49(1-e-0.249 8(t+0.289 8))、Wt=133.18(1-e-0.249 8(t+0.289 8))3.294 3,体重生长拐点年龄为4.48龄;异鳔鳅鮀属于r-选择类型鱼类。当前长江上游异鳔鳅鮀群体生长特征较2001～2002年已发生变化,因此有必要采取保护措施。

Age Structure, Growth Characteristics and Life-history Pattern of Xenophysogobio boulengeri

A total of 405 specimens of Xenophysogobio boulengeri were collected from October 2010 to July 2011 in the upper reaches of the Yangtze River. The age structure and growth characteristics were studied by otolith, then the life history pattern was concluded by the method of fuzzy cluster analysis. The results showed that,the catch consisted of four age groups and individuals of age 1 to 2 groups were dominant,occupying more (83.70%). The relationship between body length and weight was described by formula W=5×10^-6L3.294 3(r²=0.941 3, n=405, F=6 040.22, P<0.01). The body length and otolith radius could be expressed as L=0.000 8R²-0.168 4R+42.504(r²=0.836 5, n=399, F=399.20, P<0.01). The von Bertalanffy equations of the species were calculated by L_t=179.49(1-e^{-0.249 8(t+0.289 8)}), W_t=133.18(1-e^{-0.249 8(t+0.289 8)})^{3.294 3}. The age inflection point of body weight was estimated at 4.48 years. According to the typical characteristics of r and k selection and the results of fuzzy cluster analysis, it was concluded that the life-history pattern of X.boulengeri tended to r-selection. Compared with samples of this fish from the study area in 2001-2002, the growth characteristics of them have changed in the upper reaches of the Yangtze River, therefore it is urgent to take protective measures for this fish.