嘉陵江下游白缘(鱼央)年龄与生长的研究

Studies on the Age and Growth of Liobagrus marginatus(Günther) in the Downstream of Jialing River

[目的]初步探讨嘉陵江下游白缘(鱼央)的年龄与生长。[方法]的以2003年采集于嘉陵江下游合川的白缘(鱼央)为对象,对其年龄和生长进行了研究。[结果]渔获物由1～5龄组成,以2龄鱼为主,占统计总量的62.27%;体长范围在40.5～72.0 mm,以55.0～65.0 mm为主,占标本总数的81.31%;体重范围为1.3～7.5 g,以2.5～5.5 g为主,占总标本数的85.50%。体长与体重的关系式为y=0.031 3x2.7568(r2=0.792 4),属于等速生长型。雌雄个体各龄的体长、体重生长不存在显著差异。雌性的肥满度较雄性大,且肥满度与年龄有关。雌、雄个体的肝指数存在显著差异。采用抛物线方程拟合白缘(鱼央)的生长方程所得体长、体重的生长方程分别为:y=0.037 4x2+0.332 7x+4.776 6;y=0.042 6x2+0.806 3x+1.912 0。[结论]为白缘(鱼央)的深入研究及资源保护和利用提供了理论依据。

[Objective] The aim was to explore the age and growth of Liobagrus marginatus（Günther） in the downstream of Jialing River.[Method] Age and growth of Liobagrus marginatus（Günther） which was collected in 2003 from the downstream of Jialing River were studied.[Result] The catch was consisted of 5 ages,among them the 2-age group was dominant,which accounted for 62.27% in catch of the fish.The body length varied from 40.5 mm to 72.0 mm,among them 55.0-65.0 mm accounted for 81.31% of all the specimen.The body weight varied from 1.3 g to 7.5 g,among them 2.5-5.5 g was dominant,which accounted for 85.50%.The relation formula between body length and body weight was：y = 0.031 3x2.756 8（r2= 0.792 4）,so L.marginatus belonged to the type whose every part grew equably,and there wasn＇t significant difference between male and female fish.The relative fatness of female fish was more than that of male fish,furthermore it was related to age.There was significant difference in liver index between male and female fish.The equations of body length and body weight were y =0.037 4x2 ＋0.332 7x ＋4.776 6 and y =0.042 6x2 ＋0.806 3x＋1.912 0,respectively.[Conclusion]The research provides theoretical basis for the further study on L.marginatus and the protection and utilization of resource.