Seasonal migrations of pregnant blue sharks Prionace glauca in the northwestern Pacific
Seasonal migrations of pregnant blue sharks Prionace glauca in the northwestern Pacific
复制标题
西北太平洋怀孕蓝鲨的季节性迁徙
DOI：
10.3354/meps13557
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发表时间：
2020
影响因子：
2.5
通讯作者：
M. Kai
中科院分区：
文献类型：
--
作者：
Y. Fujinami;K. Shiozaki;Y. Hiraoka;Y. Semba;S. Ohshimo;M. Kai
关于高度迁徙物种迁徙的信息对于了解它们的生态，包括栖息地利用、种群连通性和种群结构，以实施适当的管理和保护措施非常重要。蓝鲨Prionace gluca(Carcharhinidae)是高度迁徙、全球分布、具有重要生态和经济价值的顶端海洋捕食者之一；然而，怀孕雌性的迁徙模式尚不清楚。在这里，我们使用弹出式卫星档案标签来阐明怀孕的蓝鲨在西北太平洋的季节性迁徙。在24个标记的成年女性中，随后获得了21个个体的档案数据(尾前长度141.1-243.3厘米)。根据超声检查或性类固醇激素分析，其中17名女性在释放时被确认怀孕。带有小胚胎的雌性在秋季和次年春季向东北方向迁徙，从亚热带(10-30°N)进入温带(30-40°N)水域；其中2只雌性在春季和夏季返回亚热带水域。相比之下，雌性大胚胎在春秋季节向西南方向迁徙，从温带进入亚热带水域。被标记的鲨鱼在潜水行为上也表现出地区差异，反映了海洋环境中的热栖息地。我们的发现表明，怀孕的蓝鲨在一年内经历了从东北到西南的季节性迁徙，在多产的温带水域生下了幼崽。这是关于怀孕蓝鲨在全球海洋中季节性繁殖迁徙的首次报道。
Information on the movements of highly migratory species is important to understand their ecology, including habitat use, population connectivity, and stock structure, to implement appropriate management and conservation measures. The blue shark Prionace glauca (Carcharhinidae) is highly migratory, has a global distribution, and is ecologically and economically important as one of the most abundant apex marine predators; however, the migration patterns of pregnant females are unknown. Here, we used pop-up satellite archival tags to elucidate seasonal migration of pregnant blue sharks in the northwestern Pacific. Of 24 tagged adult females, archival data were subsequently obtained for 21 individuals (141.1-243.3 cm precaudal length). Based on ultrasonography or analysis of sex steroid hormones, 17 of these females were confirmed to be pregnant at the time of release. Females with small embryos moved in a northeasterly direction, from subtropical (10-30°N) into temperate (30-40°N) waters during autumn and the following spring; 2 of these females returned to subtropical waters in spring and summer. In contrast, females with large embryos moved in a southwesterly direction, from temperate into subtropical waters during spring and autumn. Tagged sharks also showed regional differences in diving behaviors, reflecting thermal habitats in the ocean environment. Our findings indicate that pregnant blue sharks undergo a seasonal northeast-southwest migration within a year to give birth to pups in productive temperate waters. This is the first report on seasonal reproductive migration of pregnant blue sharks in the global ocean.