北太平洋东部柔鱼群体角质颚生长特性分析

Growth characteristics analysis of Ommastrephes bartramii beaks in eastern North Pacific

角质颚是头足类重要的硬组织,蕴含着丰富的生态信息。本文根据2010年5~6月和2012年5~7月我国鱿钓船在北太平洋海域(170°E^172°W、38°N^41°N)采集的柔鱼(Ommastrephes bartramii)样本,对柔鱼东部群体的角质颚形态特征进行分析,并结合利用耳石推测的柔鱼日龄建立其生长方程。主成分分析认为,上头盖长(UHL)、上脊突长(UCL)和上侧壁长(ULWL)为柔鱼上颚的主要形态参数,下喙长(LRL)、下喙宽(LRW)和下侧壁长(LLWL)为柔鱼下颚的主要形态参数。AIC(Akaike’s information criterion)准则认为,6项角质颚主要参数与日龄的关系均以自然对数建立的生长方程为最适。分析发现,上颚生长方程的系数均大于下颚,说明上颚的生长速度大于下颚,而喙部生长方程的系数相近且最小,说明喙部生长速度较慢;上下颚比较发现,上颚头盖脊突较下颚的生长快,而喙部和翼部的生长相似。

Beaks are important hard tissues in cephalopods,they contain a lot of ecological information. In this paper,based on samples of neon flying squid collected by Chinese jigging vessels from May to June in2010 and May to July in 2012 in eastern North Pacific（ 170° E-172° W,38° N-41° N）,we analyzed morphological characteristics of neon flying squid beaks and established growth equations based on age in days. Results of principal components analysis showed that UHL,UCL and ULWL were main morphological parameters of upper beak and LRL,LRW and LLWL were main morphological parameters of lower beak.According to Akaike ＇s information criterion,the optimum growth equations for all 6 main morphological parameters of beaks were based on natural logarithm. Results showed that coefficients of growth equations in upper beak were larger than that in lower beak,meaning that the growth of upper beak was faster than that of lower beak. Similarly,growth of rostrums were the slowest in both upper and lower beaks. Comparing upper and lower beaks,we found that growth in upper hood was faster than that in lower hood.