西江广东肇庆段赤眼鳟的年龄鉴定及生长研究

Age and growth of Spualiobarbus curriculus from Zhaoqing Guangdong Section of Xijiang River

于2006年5月～6月和2008年5月在珠江的干流西江广东肇庆段采用刺网捕捞赤眼鳟(Spualiobarbus cur-riculus)标本296尾。采集赤眼鳟的鳞片材料进行年轮特征观察研究,并对赤眼鳟的生长情况进行分析。结果表明,渔获中3龄、4龄赤眼鳟占优势。3龄前体长的相对增长率较大,3龄以后生长缓慢。赤眼鳟体质量生长曲线拐点为8龄,应属衰老拐点。总死亡系数Z=0.337 9,自然死亡系数M=0.193 6,捕捞死亡系数F=0.144 3,开发率为E=0.427。为确保资源的可持续利用,可允许捕捞体长应不小于230 mm,体质量不小于220 g。

In base of the 296 specimens of Squaliobarbus curriculus captured by gill-net in the Zhaoqing Guangdong section of Xijiang River during May June, 2006 and May, 2008, we observed the annual rings on scales of S. curriculus and studied the growth of the fish. The results reveal that the individual catches of age 3 and age 4 are dominant. The relative growth rate of length is greater before age 3 and then decreases. The inflexion point of weight growth curve is aging inflection point at age 8. The total mortality coefficient Z is 0. 337 9 ; the natural mortality coefficient M is 0. 193 6 ; the fishing mortality coefficient F is 0. 144 3 ; the fishing mortality rate E is 0. 427. To protect the fishery resources, the capture specifications of length should not be less than 230 mm and the weight should not be less than 220 g.