南海中南部海域春秋季鸢乌贼繁殖生物学特征研究

以2012年9月(秋季)与2013年3月(春季)在南海中南部采集的4 016尾鸢乌贼(Sthenoteuthis oualaniensis)样本为基础, 对南海中南部鸢乌贼繁殖生物学特征进行研究分析。结果显示, 春、秋两季鸢乌贼雌雄个体比例均为1：1; 性腺发育为春季Ⅰ、Ⅱ期所占比例较高, 秋季Ⅱ、Ⅲ期所占比例较高; 性腺成熟度指数(GSI)表现为秋季高于春季, 雄性高于雌性的变化规律; 在成熟雌性个体中, 当胴长141 mm或 150 mm时, GSI 均随胴长的增长而升高, 其中121~140 mm胴长组GSI最高, 高达9.71; 春、秋两季鸢乌贼个体绝对繁殖力变动范围分别为63~97 074粒和24～60 378粒, 均值分别为8 635粒和10 234粒, 秋季鸢乌贼繁殖能力较春季强; 鸢乌贼个体绝对繁殖力与胴长、体质量、纯体质量均呈显著正相关关系(P0. 01)。鸢乌贼成熟卵径范围为400～1 200 m, 均值为(769261) m。结果表明, 鸢乌贼的卵径小, 属异步成熟、分批产卵类型, 具有较强的繁殖潜力。

Reproductive biology of purpleback flying squid (Symplectoteuthis oualaniensis) in the south-central South China Sea in spring and autumn

We studied the reproductive biology of Sthenoteuthis oualaniensis in the south-central South China Sea using a total of 4 016 specimens collected in September 2012 and March 2013. The sex ratio of S.oualaniensis was about1:1. The proportion of StageⅠand StageⅡ was higher in spring, while that of StageⅡ and StageⅢ was higher in autumn. Gonad somatic index (GSI) was higher in autumn and male. For mature female, when mantle length was less than 141 mm or more than 150 mm, GSI increased with increasing mantle length. The highest GSI was 9.71 when the mantle length was 121～140 mm. The individual absolute fecundity was 63～97 074 eggs and 24～60 378 eggs, the average was 8 635 eggs and 10 234 eggs in spring and autumn, respectively. The fecundity was stronger than that in autumn. The individual absolute fecundity was positively correlated with mantle length, body weight and net body weight very significantly (P0. 01) . The mature egg diameter distribution range was 400～1 200 mwith an average of (769 261) m. The results indicate that the reproductive strategy characteristics of S.oualaniensis were small eggs, asynchronous mature,batch spawning and high fecundity.