Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115, USA.
J Fish Biol. 2013 Jul;83(1):170-89. doi: 10.1111/jfb.12160. Epub 2013 Jun 17.
The diel vertical migration (DVM) of Pacific cod Gadus macrocephalus was examined using depth and temperature data from 250 recaptured archival tags deployed on G. macrocephalus in the eastern Bering Sea and in the Gulf of Alaska near Kodiak Island. DVM of two types, deeper during daytime (type I) and deeper during night-time (type II), occurred frequently (15-40% of all days) in G. macrocephalus released at all sites. Most individuals displayed both diel types, with each type of behaviour lasting up to 58 contiguous days, and day and night depth differences averaging c. 8 m. Despite high among-individual variability, the occurrence of DVM varied significantly with the release site, season (i.e. day-of-year) and bottom depth, with the trend in seasonal occurrence nearly opposite for type I compared to type II DVM. No significance could be attributed to G. macrocephalus fork length, sex or ambient (tag) temperature. Trends in the magnitude of G. macrocephalus depth change were observed, with increased movement often occurring during night-time, dawn and dusk, and at release sites where the bathymetry was more complex. Both type I and type II DVMs were attributed to foraging on prey species that also undergo DVM, and increased vertical movements of G. macrocephalus during crepuscular and night-time periods were attributed to more active foraging during dim-light conditions when G. macrocephalus can potentially exploit a sensory advantage over some of their prey.
我们利用在东白令海和科迪亚克岛附近的阿拉斯加湾的 250 个回收的档案标签记录的深度和温度数据，研究了太平洋鳕鱼 Gadus macrocephalus 的昼夜垂直迁移（DVM）。两种类型的 DVM（白天更深的类型 I 和夜间更深的类型 II）经常发生（所有天数的 15-40%），释放的 G. macrocephalus 各地点都有。大多数个体表现出两种昼夜类型，每种行为持续长达 58 天，白天和黑夜的深度差异平均约为 8m。尽管个体间存在高度的变异性，但 DVM 的发生与释放地点、季节（即一年中的天数）和底部深度显著相关，与类型 I 相比，类型 II DVM 的季节发生趋势几乎相反。G. macrocephalus 的叉长、性别或环境（标签）温度与 DVM 的发生没有显著关系。观察到 G. macrocephalus 深度变化幅度的趋势，夜间、黎明和黄昏以及底形更复杂的释放地点通常会发生更多的运动。类型 I 和类型 II DVM 都归因于捕食也经历 DVM 的猎物物种，G. macrocephalus 在黄昏和夜间期间的垂直运动增加归因于在微光条件下更积极的觅食，此时 G. macrocephalus 可能相对于其一些猎物具有感官优势。
