Diet of late larval Japanese anchovy Engraulis japonicus in the Kii Channel, Japan

摘要

The diet of late larval (standard length 17.0–24.9 mm) Japanese anchovy Engraulis japonicus collected from the Kii Channel between April 2007 and March 2008 was analyzed. The main prey items found in the gut were copepods, and the composition of the gut contents changed on a monthly basis. The most important prey items were Calanoida (unidentified) from June to August and in October–November, Oncaea in March, April, and September, and Oithona in December and January. The prey selectivity analysis demonstrated that the selectivity for a particular prey category was not consistent throughout the months. It was considered that late larval anchovy may actually have no preference for a particular prey category. The major size (body width) of the prey items consumed fell within the range of 0.10–0.40 mm throughout almost the whole year. Late larvae tended to select relatively larger prey items from the environment. The relationship between the seasonal variabilities in diet and the fishery catch of anchovy “shirasu” (larvae of anchovy) is also discussed. Keywords Copepod - Gut contents - Prey selectivity - Season - Zooplankton