东黄海外海蓝点马鲛的耳石生长形态变化分析

Variation of otolith growth and morphology of Scomberomorus niphonius off East China Sea and Yellow Sea

鱼类耳石外部形态变化与生长有着密切的关系。利用2017年9月—2018年3月间在东、黄海外海采集的335尾蓝点马鲛样本,以耳石长、耳石宽、背长、背宽、腹喙长和基叶长为基本形态学参数,运用函数拟合、方差分析及小波分析等方法,研究蓝点马鲛耳石与生长之间的关系。结果显示,蓝点马鲛耳石呈乳白色,近似长方形,背面外凸、正面内凹,外部有较多突起的小齿,呈锯齿状,整体弯曲呈现瓦状。左右矢耳石没有显著性差异。蓝点马鲛耳石质量及6项形态参数指标均与叉长有着显著的关联,均为幂函数拟合结果最优。随着蓝点马鲛生长,该鱼耳石形态特征随叉长变化差异显著,耳石的总长度不断增加,而背区和腹区不断向耳石中心缩小,后区长度增加,翼长也不断增加,总体上呈现纵向缩小,横向增长的趋势且在350~400 mm时的生长与其他叉长组有着显著的不同。

Using the 335 Scomberomorus niphonius samples collected from off East China Sea and Yellow Sea from September 2017 to March 2018,the relationship between otolith and growth was studied by means of function fitting,variance analysis and wavelet analysis,taking TL,TW,DL,DW,VL,and WL as the basic morphological parameters.Based on the samples of 335 Scomberomorus niphonius collected off East China Sea and Yellow Sea between September 2017 and March 2018,the relationship between the ontogenetic shape changes of otoliths and growth was studied by the basic morphological parameters of otolith length,otolith width,dorsal length,dorsal width,ventral length and wing length,using the methods of function fitting,the ANOVA,the Least Significant Difference(LSD)analysis and wavelet analysis.The results showed that the otolith of Scomberomorus niphoniusis milky white,approximate rectangular,the back convex,the front concave,the outside had more protruding small teeth,serrated,the overall bending to show the tile shape.There was no significant difference between the left and right sagittal otolith.The weight of the otolith and 6-item morphological parameters were significantly correlated with the fork length,and all of them were the best fit results of the exponentiation function.With the growth of Scomberomorus niphonius,the morphological characteristics of the otolith varied significantly with the fork length,and the total length of the otolith was increasing,and the dorsal and ventral regions continued to shrink to the center of the otolith.The length of the posterior region increased,and the wing length increased,with the overall appearance of vertical shrinkage and horizontal growth trend.