碧流河水库鲢、鳙的年龄、生长和资源量的研究

The Age ,Growth and Resources of Silver Carp(Hypophthalmichthys molitrix)and Bighead Carp(Aristichthys nobilis )in Biliuhe Reservoir

根据１９８９～１９９１年间对碧流河水库鲢、鳙的取样调查分析，对该水库渔获物中鲢、鳙的年龄、生长和可捕群体的资源量进行了初步研究。渔获物中鲢、鳙均以Ⅳ、Ⅴ、Ⅵ龄为主，ＶｏｎＢｅｒｔａｌｌａｎｆｆｙ生长方程适合描述其生长过程。鲢的可捕群体资源量为２．９９×１０￣５ｋｇ，鳙为３．７５×１０￣５ｋｇ。

This paper deals with the age composition ,growth and catchable group resources of silver carp and bighead carp in Biliuhe reservoir.The two species are largely composed of age groups Ⅳ,Ⅴ and Ⅵ in catches. The relationship between the body length and scale radius can be expressed by the etluation L=.85 +18. 07R for silver carp,L=2. 71+16. 23R for bighead carp. The reIationship be- tween body weight and body length can be expressed as W=2.3794× 10￣(-5)L ￣2.9583 for silver carp,w=3. 627×10￣(-5)L￣2.8752 for bighead carp. The results show that the growth patterns of the two species can be described by Von Bertalanffy growth equation pretty well,the parameter values of which for silver carp are L_∞=70. 43 cm,W_∞=6.96kg,k=0.2285,t_0=-0.4773yr,t_r=4.4yr; and those forbighead carp are L_∞=94.05cm,W_∞=17.11 kg,k=0.1915,t_0=-0.04yr,t_r=25. 7 yr.The catchable group resources of silver carp and bighead carp are 2. 99 ×10￣5 kg and 3. 75×10￣5 kg respectively.The aging of elder ones, the suitable catching number,the comparison of catching composition in difterent netting gears and the slow-growing ones are discussed.