拉尼娜发生期东海太平洋褶柔鱼耳石生长特征

Growth characteristic of statolith of Todarodes pacificus in the East China Sea in the La Nina year

为研究拉尼娜与正常年东海太平洋褶柔鱼的耳石外形生长特征差异,对2020年间(正常年)和2021年间(拉尼娜年)2—4月我国灯光围网船在东海海域生产调查期间采集的太平洋褶柔鱼样本进行了分析。结果表明:耳石总长(TSL)、侧区长(LDL)、翼区长(WL)和最大宽度(MW)可作为描述东海太平洋褶柔鱼耳石外形生长特征的表征参数。不同气候年间、不同性别耳石的形态表征参数均具有显著性差异:正常年样本的耳石表征参数值均大于拉尼娜年;除拉尼娜年的TSL,其余表征参数均表现为雌性大于雄性。生长方程表明,不同气候年间雄性均较雌性耳石增长更快,正常年TSL、LDL和WL增长更快,拉尼娜年MW增长更快。太平洋褶柔鱼耳石的相对尺寸随个体生长均呈现逐渐减缓的趋势。

To investigate the differences on morphological growth patterns of statolith of Todarodes pacificus in the East China Sea during La Nina and normal years,we analyzed the samples of T.pacificus collected in the East China Sea by Chinese light purse seine fishery fleets from February to April in 2020(a normal year)and 2021(a La Nina year).The results showed that total statolith length(TSL),lateral dome length(LDL),wing length(WL),and maximum width(MW)could be used as characterization parameters to representing the morphological growth of statolith.The characterization parameters of statolith in T.pacificus differed significantly between different climate years and between different genders.The values of those characterization parameters of statolith were greater in normal year than those in La Nina year,which in both years were larger in females,except for TSL in males in La Nina year.The statolith growth of males were faster than that of females in different climate years.TSL,LDL,and WL increased faster in normal year,while MW increased faster in La Niňa year.The relative size of statolith gradually slowed down with the growth of individuals.