赤水河半年龄与生长

Age and Growth of Hemiculterella sauvagei from the Chishui Riverin the Upper Reaches of the Yangtze River

2011年7～12月在长江上游一级支流赤水河的赤水市河段采集371尾半Hemiculterella sauvagei样本,以鳞片为年龄鉴定材料,对其年龄结构与生长特征进行了研究。结果表明:半鳞片的年轮结构呈普通疏密型,年轮特征显著,可用于年龄鉴定。半样本的体长主要分布在80～120mm,占总数的86.8%;体重主要分布在5～25g,占总数的96.2%;年龄在1～4龄,其中以2～3龄居多,共325尾,占总数的87.6%。体长和鳞径关系雌雄群体间无显著差异,其表达式为:L=39.522R+25.403;体长和体重关系雌雄群体间无明显差异,其表达式为:W=2×10-5L2.872;其生长属于等速增长类型,生长规律可以用Von Bertalanffy生长方程表示为:Lt=176.1[1-e-0.275(t+1.13)];Wt=59.54[1-e-0.275(t+1.13)]2.872;体重生长曲线的拐点为2.706龄,其对应的体长和体重分别为114.78mm和17.41g。为保护赤水河半的鱼类资源,应该加强对其捕捞的管理,限制网目的大小。

Age and growth of Hemiculterella sauvagei were determined using 371 samples collected from the middle reaches of Chishui river, one of the first-order tributaries of the Yangtze River, China, from July to December 2011. The results showed that the fish scale is an appropriate material for age determination. The standard length of the samples mainly ranged from 80 - 120 mm, accounting for 86.8% of the total; total weight mostly ranged from 5 - 25 g, making up 96.2% of the total. Four age groups were identified; individuals of 2 - 3 years old were dominated, representing 87.6% of the total catch. The relationship between standard length and scale radius showed no significant difference between males and fe- males, which could be expressed as： L = 39. 522R ＋ 25. 403; the relationship between standard length and total weight also showed no significant difference between males and females, which could be expressed as： W=2×10^-5L2.87. The growth ofH sauvagei was in a constant speed which can be described with von Bertanlanffy equation： L1 = 176. 1 [ 1 -^e 0.2750＋1.13）] ; W, =59.54[ 1 -e^-0.275（t＋1.13）] 2.872. The growth inflexion point of total weight was at age 2. 706, with the corresponding standard length of 114.78 mm and total weight of 17.41 g. In order to better protect the resource of H. sau- vagei, measures such as strict ban to unreasonable catching and to restrict the size of fishing net should be enhanced.