Diel activity and vertical distribution of Lysianassoid amphipods dominant in Onagawa Bay, north-eastern Japan
Diel activity and vertical distribution of Lysianassoid amphipods dominant in Onagawa Bay, north-eastern Japan
复制标题
日本东北部女川湾优势的 Lysianassoid 片脚类的昼夜活动和垂直分布
DOI：
10.1111/j.1444-2906.2004.00896.x
复制
发表时间：
2004
影响因子：
1.9
通讯作者：
M. Omori
中科院分区：
文献类型：
--
作者：
A. Takekawa;K. Sasaki;M. Omori
采用诱捕法，对日本东北部女川湾3种优势食蚜类片足类（Scopelocheirus onagawae, Anonyx omorii, Anonyx abei）的昼夜活动和垂直分布进行了研究。这三个物种是该海湾最具优势的小型甲壳类食腐动物。大多数个体被放置在海底上方0.3米的陷阱捕获，这表明它们在靠近海底的层中活动。在物种或发育阶段之间没有发现栖息地隔离，表明这些食腐动物依赖于底部沉积物的食物供应。这三个物种在夜间收集的个体数量显著增加，表明摄食活动增加。两种无性系植物仅在夜间采集，而女川花以夜间采集为主。夜间活动似乎是为了减少被捕食的风险。然而，S. onagawae的幼鱼甚至在白天出现，这表明进食可能优先于避免捕食。用诱捕器捕获野蔷薇属的雌雌，但未收集到雌雄同体的雌；造成差异的原因无法确定。
: Baited traps were used over 24 h to reveal the diel activity and vertical distribution of three dominant lysianassoid amphipods (Scopelocheirus onagawae, Anonyx omorii, Anonyx abei) in Onagawa Bay, north-eastern Japan. The three species were the most dominant small crustacean scavengers in the bay. Most individuals were caught by traps deployed 0.3 m above the bottom, showing that they were active in the layers close to the sea bottom. No habitat segregation was found among species or developmental stages, suggesting that these scavengers rely on the food supply from bottom deposits. The three species increased remarkably in numbers of collected individuals at night, showing a rise in feeding activity. The two Anonyx species were collected only during the night, and S. onagawae was collected mostly during the night. The nocturnal activity appears to be an adaptation to reduce predation risks. However, juveniles of S. onagawae appeared even during the day, suggesting that feeding might take precedence over avoiding predation. Baited traps collected ovigerous females of S. onagawae but not of Anonyx species; the reason for the difference could not be determined.