智利外海茎柔鱼耳石生长特性的性别差异研究

Sexual Differences in Growth Characteristics of Statolith from Dosidicus Gigas in the High Sea Waters off Chile

根据2007年1～6月和2008年1～5月我国鱿钓船在智利外海调查期间采集的茎柔鱼耳石样本,测量了503枚耳石外部形态参数(雌性348枚,雄性155枚),结合耳石日轮,对耳石生长特性的性别差异进行了研究。结果表明,耳石总长(TSL)、耳石半径(SR)、吻侧区长(RLL)、翼长(WL)及最大宽度(MW)可作为茎柔鱼耳石形态的表征参数。雌雄个体间耳石的生长在5个形态参数上均存在显著性差异,雌性个体TSL与日龄间关系最适为指数函数,SR和RLL为幂函数,MW和WL则为线性函数;雄性个体的TSL、SR和RLL与日龄间的关系最适为幂函数,MW和WL为线性函数。雌性个体TSL、SR、MW、RLL、WL的相对生长率和SR、RLL绝对生长率均随着日龄的增加而先增加后减小,TSL、MW绝对生长率随着日龄的增加而增加,WL绝对生长率则随着日龄增加而呈现波动趋势;雄性个体TSL、SR相对生长率和MW、RLL、WL绝对生长率随着日龄增加先增加后减小,而MW、RLL和WL相对生长率和TSL、SR绝对生长率则随日龄增加呈现波动趋势。研究认为,茎柔鱼耳石生长存在性别差异,通常雌性生长较雄性快。

The statolith samples of Dosidicus gigas were collected by Chinese squid fishing vessels in the high sea waters off Chile from January to June 2007 and Janurary to May 2008. The statolith morphological parameters of 503 individuals （348 for females and 155 for males） were measured, and the statolith growth characteristics were studied combined with the age data. The results showed that the total statolith length （TSL）, statolith radius （SR）, rostrum lateral dome length （RLL）, wing length （WL） and the maximum width （MW） were considered as the feature parameters of squid statolith. The growth of main parameters of statolith between male and female individuals were significantly different. For female squid, the relationship between TSL and age was the best for the exponential function, SR-age and RLL-age followed the power function, MW-age andWL-age were described by the linear function. While for the male squid, the relationships of TSL-age, SR-age and RLL-age were described by the power function, MW-age and WL-age were linear function. For female squid, the relative growth rates of TSL, SR, MW, RLL and WL, and the absolute growth rate of SR and RLL increased with age firstly and then decreased. The absolute growth rates of TSL and MW increased with age, and the absolute growth rate of WL fluctuated with increase of age. While for the male squid, the relative growth rate of TSL and SR, and the absolute growth rates of MW, RLL and WL increased with age firstly and then decreased, the relative growth rates of MW, RLL and WL, and absolute growth rate of TSL and SR fluctuated with age. The results suggested that the statolith growth of Dosidicus gigas had the sexual differences and the growth rate of males was larger than that of males in general.