We examined the distribution and feeding habits of the diel vertical migratory myctophid Myctophum orientale in the Kuroshio region of the western North Pacific in late winter. All 1985 specimens collected were in the juvenile stage, with a mean standard length (SL) of 29.9 mm. They occurred on the onshore side of the Kuroshio axis along the slope region off Japan, showing a typical pseudoceanic distribution. Juveniles <35 mm SL depended heavily on appendicularians, while juveniles ≥35 mm SL preyed on various species of copepods (predominantly Candacia bipinnata) and euphausiid calyptopis and furcilia stages. Based on estimated biomass (2.85 mg m^-3) and nighttime ration (10.5–13.8% of body weight d^-1), the predatory impacts of M. orientale on the biomass and production rate of the mesozooplankton were calculated to be 0.3–0.8% and 6.0–15.5%, respectively, in the surface layer. In the study area, M. orientale co-occurs with larvae and juveniles of Japanese sardine and mackerels, both of which also prey on appendicularians. Predatory impacts of M. orientale <35 mm SL on the biomass and production rate of appendicularians were estimated to be 2.5–7.4% and 4.7–14.1%, respectively. This suggests that M. orientale is a competitor for prey with the small pelagic fish on the onshore side of the Kuroshio axis during late winter.

我们在冬季末检查了北太平洋西部黑潮地区Diel垂直迁徙的Myctophum Orientale的分布和摄食习惯。1985年收集的所有标本均处于幼年期，平均标准长度（SL）为29.9毫米。它们发生在黑潮轴的陆上，沿着日本以外的斜坡区域，显示出典型的假洋分布。<35 mm SL的幼鱼严重依赖于阑尾虫，而≥35mm SL的幼虫则捕食各种pe足类动物（主要是Candacia bipinnata）以及长足的萼花ly和糠fur阶段。根据估计的生物量（2.85 mg m ^-3）和夜间比例（体重d ^-1的10.5–13.8％），捕食性动物的掠食性影响M.东方对浮游动物的生物量和生产速率被计算为分别0.3-0.8％和6.0-15.5％，在表面层中。在研究区域中，东方支原体与日本沙丁鱼和鲭鱼的幼虫和幼虫共存，它们都以阑尾虫为食。＜35 mm SL的东方支原体对掠食生物的生物量和生产率的掠食性影响估计分别为2.5–7.4％和4.7–14.1％。这表明，冬末时分东方侧M是一个竞争者，在黑潮轴的陆上一侧有小型浮游鱼类。