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养殖条件下的性早熟、个体小型化是影响曼氏无针乌贼(Sepiella japonica)的养殖效益的重要因素。为探讨养殖条件下曼氏无针乌贼性早熟的可能因素,本文探讨了3种不同光照周期(23D:1L;12D:12L;1D:23L)对其繁殖性能及个体生长的影响。结果表明:光照周期对曼氏无针乌贼的繁殖性能总体影响不大,除长光照周期(1D:23L)下,睾酮(T)、雌二醇(E2)等激素水平有较显著的降低外(P<0.05),光照对乌贼繁殖时间、性腺重及性腺发育指数等指标均无明显影响。但光照周期对曼氏无针乌贼生长却有明显影响,在胴长、体重、瞬时生长率(IGR)及肥满度等生长指标上均呈现出短光照组>中光照组>长光照的趋势。短光照组雌乌贼在体重、瞬时生长率和肥满度,雄乌贼在胴长等指标上,均显著优于长光照组(P<0.05)。该结果表明光照周期可作为影响曼氏无针乌贼生长性能的重要因素,在今后的养殖条件优化中应加以考虑。
Precocious puberty and individual miniaturization under culture conditions are important factors affecting the breeding efficiency of Sepiella japonica. In order to explore the possible reasons for the precociousness of Manchurian squid, the effects of three different photoperiod (23D: 1L; 12D: 12L; 1D: 23L) on the reproductive performance and individual growth were investigated. The results showed that the photoperiod had no significant effect on reproductive performance of Pinnacle squid, and the hormone levels of testosterone (T) and estradiol (E2) decreased significantly under long photoperiod (1D: 23L) (P <0.05). The illumination had no significant effect on reproduction time, gonad weight and gonadal development index of squid. However, the photoperiod had a significant effect on the growth of Pinnacle squid, and showed the trend of short light group> medium light group> long light on growth index such as body length, body weight, instantaneous growth rate (IGR), and plumpness . Short-light group female squid in weight, instantaneous growth rate and fatness, male squid in the carcass length and other indicators were significantly better than the long light group (P <0.05). The results showed that the light cycle can be used as an important factor affecting the growth performance of Pinnacle squid, and should be considered in the future optimization of farming conditions.