剑尖枪乌贼个体生长年间差异及其影响因素

根据2017-2020年拖网渔船在东海北部外海采集的剑尖枪乌贼(Uroteuthis edulis)调查数据,分析剑尖枪乌贼的生物学特征,并利用广义加性模型(generalized additive models ,GAMs)研究该海域剑尖枪乌贼的生长特性与环境的关系。结果表明,在4年采样期间,剑尖枪乌贼的优势胴长和体质量组雌性分别为80-160mm和10-170g,不存在显著性差异(P>0.05)；雄性分别为60-180mm和10-170g,存在年间显著性差异(P<0.01)。协方差分析表明,2017、2020年个体体质量-胴长关系差异显著(P＜0.05),2018、2019年个体差异不显著(P＞0.05)。性成熟胴长与性腺成熟度存在年间差异,且雌雄性成熟胴长均随水温存在相同的变化趋势。GAMs结果表明,包含25m深处水温(交互)、年份和季节的GAM模型是最优模型,整体来看雄性个体生长过程较雌性更容易受外界环境的影响,年份对于雄性个体的影响更大,而雌性个体相对受25m深处水温的影响较大。因此,剑尖枪乌贼的生长与周围环境变动密切相关,在不同年间水温是重要的影响因子,受环境变动影响和个体生存机制的制约,剑尖枪乌贼雄性较雌性在160mm胴长处存在更明显的形态不同的大小个体群。探究剑尖枪乌贼的生物学特性及环境对它的影响有助于渔业资源的管理和保护,为渔业资源评估做进一步研究。

Interannual variability of the swordtip squid (Uroteuthis edulis) and its relevant impact factors

Based on the survey data of swordtip squid (Uroteuthis edulis) collected by trawlers off the northern East China Sea from 2017 to 2020, the biological characteristics of U. edulis were analyzed, and the relationship between the growth characteristics of U. edulis and the environment in this sea area was studied using generalized additive models (GAMs).The results showed that during the four-year sampling period, the dominant dorsal mantle length and body weight groups of the U. edulis are 80-160mm and 10-170g for females respectively, with no significant differences (P>0.05); and 60-180mm and 10-170g for males respectively, with significant differences between years (P<0.01). Covariance analysis showed that there are significant differences in body weight-dorsal mantle length relationship in 2017 and 2020 (P<0.05), but no significant differences in 2018 and 2019 (P>0.05). There are inter-year differences in dorsal mature length and sexual maturity stages, and both males and females show the same trend of variation with the sea temperature. The results of GAMs showed that the GAM model including water temperature at 25m depth (interaction), year and season is the optimal model. Overall, the growth process of male individuals is more susceptible to the external environment than females, and year have a greater impact on male individuals, while females are relatively more influenced by the sea temperature at 25m depth. Therefore, exploring the biological characteristics of the U. edulis and the influence of the environment on it can help the fishery resources management and conservation, and can make further studies for the assessment of fishery resources.