北太平洋长鳍金枪鱼年龄与生长初步研究

北太平洋长鳍金枪鱼(Thunnus alalunga)是金枪鱼渔业的主要捕捞对象之一,其资源的养护和管理日益受到各方关注,鱼类年龄鉴定是渔业资源研究的重要内容之一。根据2013~2014年北太平洋长鳍金枪鱼探捕所采集的227个脊椎骨样本,用不同的染色方法分成4组进行年龄的鉴定,选用线性模型、指数模型和幂指数模型对叉长和脊椎骨半径进行拟合,最后选出结果最好的鉴定组和拟合模型,通过年龄鉴定估算长鳍金枪鱼的Von Bertalanffy生长方程。研究结果表明,北太平洋长鳍金枪鱼的叉长范围为52~104 cm,优势叉长组为81~90 cm,占总数的83.1%;年龄组成以5、6龄较多,占样本总数的80.86%。最终得到北太平洋长鳍金枪鱼生长方程为:Lt=109.180 21-e~(-0.258 783(t-1.991 28))],t_(tp)=2.25。

Preliminary study on age and growth of north Pacific albacore Thunnus alalunga

The north Pacific albacore Thunnus alalunga is one of the main target species of tuna fisheries,the conservation and management of its resources has caught increasing attention by regional tuna management organizations.The fish age identification is an important content of fishery resources research.There is a need for a simple practical and accurate aging method to document the population structure,age and growth of the north Pacific albacore.We collected 227 vertebrae samples of albacore in the North Pacific between 2013 and 2014,divided them into four groups for age identification in the experiment by different dyeing methods and then used linear model,exponential model and power index model to fit the relationship between the fork length and radius of vertebrae,the best historical and fitting model was chosen to calculate the Von Bertalanffy growth equation for the North Pacific albacore.Results indicated that the fork length of albacore ranged from 52 cm to 104 cm,with the average fork length of 84.79 ±4.951 cm,the dominant fork length (83.1%)was between 81 -90 mm.The fork length of female albacore ranged from 63 cm to 104 cm,with the average fork length 84.43 ±5.274 cm and the dominant length (81.82%)was between 81 -90 mm.The fork length of male albacore ranged from 52 cm to 96 cm,with the average fork length 85 .23 ±4.642 cm and the dominant fork length(80.86%)was between 81 -90 mm.The 5 and 6 age class accounted for 80.86% of the total number sampled .The single factor analysis of variance showes that there is no significant difference among four experiments in the identification of albacore age.However,the AIC index model of experimental group is lower than other three test groups,and it shows that the experimental group can better fit age-fork length relationship for albacore tuna. The Von Bertalanffy growth function is,Lt =109.180 2 1 -e -0.2587 83(t-1.991 28)],ttp=2.25.