Freshwater migration and feeding habits of juvenile temperate seabass Lateolabrax japonicus in the stratified Yura River estuary, the Sea of Japan

Abstract

Juvenile temperate seabass Lateolabrax japonicus were sampled along the Yura River estuary from April to July 2008 to determine their distribution and feeding habits during migration within a microtidal estuary. Throughout the sampling period, juvenile seabass were distributed not only in the surf zone, but also in the freshwater zone, and they were particularly abundant in areas with aquatic vegetation in the freshwater zone. This distribution pattern suggests that the early life history of the temperate seabass depends more intensively on the river (freshwater) than previously considered. Small juveniles in the freshwater zone fed on copepods and chironomid larvae and upon reaching a standard length (SL) of approximately 20 mm did they fed on mysids. In contrast, juveniles (approx. 17–80 mm SL) in the surf zone fed mainly on mysids.