利用分位数回归法估算西北太平洋柔鱼生长率

Growth rate of neon flying squid in the northwest Pacific estimated by quartile regression

柔鱼(Ommastrephes bartramii)是西北太平洋重要的经济头足类,其生长率估算是渔业生物学研究的主要内容之一。本文根据2007年7～10月西北太平洋海域连续采集的柔鱼样本,利用分位数法对其生长率进行估算。结果表明,分位数τ分别为0.05、0.1、0.25、0.5、0.75、0.9、0.95时,雌性在时间上的分位数回归系数为0.010 3、0.012 6、0.029 7、0.056 6、0.108 7、0.111 7、0.121;雄性为0.018 0、0.022 3、0.033 4、0.063 0、0.080、0.079 0、0.086 5。分析发现,胴长分布随着时间的推移,下分位数对应的回归系数受到补充群体的影响较大,其生长率的数值较小;上分位数中95%分位数回归系数比较适合,其雌、雄生长率分别为1.21 mm/d和0.8 mm/d。研究认为,利用分位数回归方法来估算柔鱼的生长率是可行的。

The neon flying squid,Ommastrephes bartramii,is an important economic cephalopd in the northwest Pacific.The estimation of growth rate is one of the main objects in the study of fishery biology.According to the sampling squid,from July to October in 2007 in the northwest Pacific Ocean,the quantile method was used to estimate the growth rate.Results suggested that when Quantile τ =（0.05,0.1,0.25,0.5,0.75,0.9,0.95）,the quantile regression coefficients with time for the female was equal to 0.010 3,0.012 6,0.029 7,0.056 6,0.108 7,0.111 7 and 0.121,for the male was 0.018 0,0.022 3,0.033 4,0.063 0,0.080,0.079 0 and 0.086 5 respectively.Based on the distribution of mantle length varied with time,the lower quantile regression coefficients was greatly affected by the size of recruitment,and the growth rate was less.The 95% percentile of upper quantile regression coefficient was more appropriate compared with the lower quantile,and the growth rates were 1.21 mm/d for the female and 0.8 mm/d for the male.It is concluded that the quantile method can be feasibly used to estimate the growth rate of Ommastrephes bartramii in the northwest Pacific Ocean.