采用耳石研究印度洋西北海域鸢乌贼的年龄、生长和种群结构

Age,growth and population structure of squid Sthenoteuthis oualaniensis in northwest Indian Ocean by statolith microstructure

利用2004—2005年中国鱿钓渔船资源探捕期间在印度洋西北部采集的104枚鸢乌贼Sthenoteuthisoualaniensis耳石样本,对其年龄和生长进行了研究。鸢乌贼的生命周期约为1年,样本年龄为88-363 d,优势年龄组为180-270 d,占总体的81.3%。样本孵化日期为2004年1—11月,几乎为全年性,但存在两个峰值：3—5月和9—10月,分别占总体的57.8%和14.4%。根据孵化日期可将鸢乌贼分为春季和秋季两个产卵群体。两产卵群体胴长与年龄符合线性方程,而体重与年龄符合指数方程模式。各胴长组间的瞬时相对生长率和绝对生长率存在变化,不同群体之间的瞬时相对生长率和绝对生长率差异明显。

The age and growth of squid Sthenoteuthis oualaniensis were studied using 104 statoliths collected in the Chinese squid jigging surveys from October 2004 to January 2005. It was found that the squid had a life span of about one year, the samples being 88 to 363 day old, 81.3% ranging from 180 to 270 day old. The incubation samples were found almost throughout the year from January to November in 2004, with two peaks of March to May and September to October, accounting for 57.8% and 14.4% of the total, respectively. Two distinct spawning groups were observed in spring and autumn. The relationship between mantle length and age was described by the linear function and the relationship between body weight and age the exponent functions in the two spawning groups. The instantaneous relative growth rate and absolute growth rate were found to be varied with the sizes, with significant difference between the groups of squid with the same age.