基于线性混合模型的不同群体柔鱼胴长体质量关系的异质性研究

Heterogeneity of mantle length-body mass relationship in different Ommastrephes bartramii populations based on linear mixed model

为研究不同群体柔鱼(Ommastrephes bartramii)生长的异质性,文章根据2016—2018年在北太平洋采集的柔鱼样本,对该物种胴长和体质量的性别和月间差异进行了分析。构建了广义线性模型(Generalized linear model,GLM)和9个线性混合模型(Linear mixed model,LMM),用于研究不同群体柔鱼的胴长和体质量关系(m=aLb)在性别及时间上的差异。结果显示,东、西部群体不同性别柔鱼胴长、体质量均存在极显著差异(P<0.01);各月份间也均存在极显著差异(P<0.01)。东部群体异速生长参数(b)的固定值(2.7634)小于3,表示其为负异速增长,肥满度随胴长增加而减少,胴体趋于细长;西部群体b的固定值(3.11719)大于3,表示其为正异速增长,肥满度随胴长增加而增大,胴体趋于宽厚。研究表明,性别和月份对不同群体柔鱼胴长和体质量关系均有显著影响,线性混合模型能将性别和月份的异质性通过随机效应在单个模型中更准确、方便地体现出来,进一步证实了此模型在个体生长异质性研究中的优势。

We had collected neon flying squid(Ommastrephes bartramii)samples from 2016 to 2018 in North Pacific,and studied their gender and monthly differences of mantle length-body mass relationship,so as to understand the heterogeneity in the growth of different O.bartramii populations.One generalized linear(GLM)model and nine linear mixed models(LMM)were applied to study the difference in gender and time for mantle length-body mass relationship(m=aLb).The results show that there was a significant difference in the mantle length and body mass between female and male O.bartramii of eastern and western populations(P<0.01).Moreover,there was a significant difference between different months(P<0.01).The fixed value of b(2.7634)was less than 3 in the eastern population,which indicates that O.bartramii was growing at negative allometry,and the degree of fullness was negatively related to mantle length,and the body tended to be slender.The fixed value of b(3.11719)was more than 3 in the western population,which indicates that O.bartramii was growing at positive allometry,and the degree of fullness was positively related to the mantle length,and the body tended to be thick.The study indicates that month and gender have a significant effect on the mantle lengthbody mass relationship for different O.bartramii populations.The LMM reflects the heterogeneity of gender and month more accurately and conveniently in a single model through random effects,thereby further confirming the advantage of this model in the study of heterogeneity in individual growth.