湘江永州段湖北圆吻鲴和似鳊年龄及生长特性

A Study of Ageand Growth Characteristics of Distoechodon hupeinensis and Pseudobrama simoni in Yongzhou Section of the Xiangjiang River

2016年4-6月在湘江永州段沿岸收集湖北圆吻鲴和似鳊标本共275尾,并进行了湖北圆吻鲴和似鳊的年龄和丰满度等生物学特征的研究。结果表明:湖北圆吻鲴和似鳊的最大年龄均为3+龄。湖北圆吻鲴1+和2+龄鱼为优势群体,似鳊1+龄鱼为优势群体。湖北圆吻鲴的优势体长在150-190 mm之间,占总数的63.42%。似鳊的优势体长在80-110 mm之间,占总尾数的65.13%。湖北圆吻鲴的体重集中分布在50-90 g,占总尾数的65.04%,似鳊的体重优势集中分布在0-30 g,占总数的79.61%。体长(L)与体重(W)回归方程分别为:湖北圆吻鲴:W=5.73×10^-5L2.764 7,R2=0.892 2;似鳊:W=4.67×10^-6L3.290 9,R=0.952 3。其幂指数都偏离于3,为异速生长鱼类。湖北圆吻鲴丰满度在0+-3+龄之间变化较大,3+龄丰满度值较低;似鳊的丰满度值随年龄增长有变小的趋势。

In April-June 2016,a total of 275 specimens of Distoechodon hupeinensis and Pseudobrama simoni were collected along the Yongzhou section of Xiangjiang River to study the biological characteristics such as age and fullness.It was found that the population of Distoechodon hupeinensis and Pseudobrama simoni was comprised of 4 age classes ranging from 0+ to 3+.The length of Distoechodon hupeinensis was dominant from 150 mm to 190 mm,representing 63.42% of the samples.The length of Pseudobrama simoni was primarily between 80 mm to 110 mm,representing 65.13% of the samples.The weight of Distoechodon hupeinensis is concentrated between 50 g and 90 g,accounting for 65.04% of the total mantissa.The weight advantage of Pseudobrama simoni is concentrated between 0-30 g,accounting for 79.61% of the total.The regression equation between body length(L) and body weight(W) was describe as W=5.73×10^-5L2.764 7,R2=0.892 2 for Distoechodon hupeinensis and W=4.67×10^-6L3.290 9, R=0.952 3 for Pseudobrama simoni.Their powers were deviation in 3,and were the allometric growth fish.The fullness of the Distoechodon hupeinensis changed greatly between 0+ and-3+,and the fullness of 3+ was lower.The fullness of the Pseudobrama simoni tends to decrease with age.