龙溪河张氏■生长与繁殖初步研究

基于2011年7-12月和2012年3-6月采集的样本,对长江上游支流龙溪河张氏■(Hemiculter tchangi)种群生长和繁殖特征进行研究。研究共采集张氏■样本227尾,采用鳞片鉴定年龄,测量鳞片半径,进行体长退算,选取成熟鱼卵描绘卵径分布,估算繁殖力,研究其年龄结构、生长特征和繁殖习性。结果显示:龙溪河张氏■体长101~187 mm,平均体长为(141±15) mm,体重12.5~82.8 g,平均体重为(39.3±13.2) g。群体雌雄性比为1.38∶1。群体年龄组成为1~5龄,其中3龄最多,占总样本的48.5%。群体体长与鳞径呈线性关系,雌雄无显著差异,其关系表达式为L=32.08 R+43.08;体长与体重的关系呈幂函数关系,其关系表达式为W=10-5×0.13.035。张氏■种群生长式型属于等速生长,生长方程表达式为:Lt=242.691-e-0.164(t+2.71)];Wt=170.661-e-0.164(t+2.71)]3.035。种群繁殖时间为4-8月,雌雄群体1龄达性成熟,其中雌性生物学最小型体长为110 mm,体重为28.7 g;雄性生物学最小型体长为105 mm,体重为14.6 g。龙溪河张氏■种群卵径为单峰型,平均卵径为(0.72±0.05) mm;种群绝对繁殖力平均为(32 688±11 426)粒;体长相对繁殖力FL平均值为(219±76)粒/mm;体重相对繁殖力FW平均值为(680±215)粒/g。

Preliminary study on growth and reproduction of Hemiculter tchangi Fang in the Longxi River

A total of 227 specimens of Hemiculter tchangi were collected in Longxi River from July 2011 to June 2012 to facilitate deeper research on its population conservation biology.Longxi River is the tributary of the upper reaches of the Yangtze River.We use scales for age identification,measuring scale radius to calculate back body length,oocytes diameter distribution was displayed through analysis oocytes histogram.The growth and reproduction characteristics of populations were analyzed.The results showed that the standard length ranged from 101 to 187 mm,with the average length of(141±15)mm,and the body weight range was 12.5~82.8 g,with the average weight of(39.3±13.2)g.The female/male ratio was 1.38:1.The age composition of the population was 1-5 years old,with 3 years old were the largest proportion(48.5%).There was a linear relationship between standard length and scale radius,and relationship expression was L=32.08R+43.08,but no significant differences were found between males and females.The relationship between standard length and weight was a power function,and the relationship expression was:W=10-5×0.13.035,while no significant differences were observed between males and females.The growth pattern of H.tchangi population was isokinetic,and the growth equation was:Lt=242.691-e-0.164(t+2.71)];Wt=170.661-e-0.164(t+2.71)]3.035.The fish spawning time was from April to August.Both males and females reached sexual maturity at the age of 1 year.The minimum sexual mature standard length and weight of females were 110 mm and 28.7 g,respectively.The minimum sexual mature standard length and weight of males were 105 mm and 14.6 g,respectively.The oocyte diameter of the H.tchangi population in Longxi River was unimodal,with an average oocyte diameter of(0.72±0.05)mm.The average absolute fertility was(32688±11426)eggs.The average standard length relative to the fertility FL was(219±76)eggs/mm.The average FW of body weight relative to fertility was(680±215)eggs/g.To scientifically and rationally protect the H.tchangi population resources in Longxi River,it is recommended to carry out scientific research on habitat protection and artificial breeding in population.