哥斯达黎加外海茎柔鱼个体与耳石间生长关系研究

Relationship between individual growth and statolith increment of jumbo flying squid(Dosidicus gigas) in the waters off Costa Rica

根据2009年7-8月哥斯达黎加外海采集的茎柔鱼样本,利用多种统计方法分析了茎柔鱼耳石与个体生长之间的关系。研究认为,耳石各形态参数与胴长（ML）关系显著（P〈0.01）,其中背侧区间长（DDL）、耳石总长（TSL）与其相关性最大。耳石生长存在两个阶段,当ML小于26~30 cm时,其耳石生长迅速,之后耳石生长减慢。在生长过程中,耳石背区长（DL）、吻区内长（R IL）、DDL生长快于TSL,背侧区夹角（DDA）、吻侧区夹角（RDA）、吻区夹角（RA）则随着ML的增大出现减小趋势,侧区、吻区形态变化显著（P〈0.05）。耳石形态先于生长速度发生显著性变化,同时各形态参量发生显著性变化时间不同,但形态特征变化主要发生在ML为23~29 cm个体中,之后趋于稳定。耳石生长及形态显著性变化与茎柔鱼栖息水层改变相关,茎柔鱼与中上层头足类耳石特征相符。研究亮点：分析了茎柔鱼耳石与个体生长之间的关系。耳石各形态变化与胴长关系显著。当胴长小于26~30 cm时,其耳石生长迅速,之后减慢。同时推测耳石生长及形态的显著性变化与其栖息水层改变密切相关。

The growth relationship between statolith and individual of the jumbo flying squid（Dosidicus gigas） sampled in waters off Costa Rica from July to August in 2009 was studied with multiple statistical methods.It was found that the growth relationship between statolith and mantle length（ML） was significant（P0.01）,and the biggest coefficient were ventral dorsal dome length（DDL） and total statolith length（TSL）.Statolith growth contained two phases,rapid growth of statolith before ML was smaller than 26-30 cm,and after that there has a slow growth of statolith.The dorsal length（DL）,rostrum inside length（RIL） and DDL grew faster than the TSL,but the ventral dorsal dome angle（DDA）,rostrum lateral dome angle（RDA） and rostrum angle（RA） were reduced during the growth process.So the morphology of lateral dome and rostrum were changed significantly（P0.05）.Although the significant changes of statolith morphology preceded the growth changes and the significant changes of various parts in morphology were not synchronized,the morphological changes mainly occurred in individuals with 23-29 cm ML,after that the morphology kept stabilized.The significant changes of growth and morphology were associated with habitat changed of water layer,and the jumbo flying squid statolith was coincided with the characteristics of pelagic cephalopods.