Distribution and food habits of eggs and larvae of Hippoglossoides dubius in Funka bay and its offshore waters, Hokkaido [Japan]

Eggs, larvae, and juveniles of Hippoglossoides dubius were collected in Funka Bay and vicinity, Hokkaido, in 1989 and 1990. Distributions of the eggs of early developmental stages showed that the eggs ware spawned in the inner area of the bay. Before the exhaustion of their yolk, larvae initiated feeding on copepod nauplii, diatom, and invertebrate eggs. The proportion of copepod nauplii in the stomachs increased with growth. Juveniles fed on large sized plankton such as copepodids, larval euphausiids, and appendicularia. Copepod nauplii, the principal food for the larvae at the early developmental stages, increased in the bay after the invasion of the Oyashio Water. It is inferred that the mortality of H. dubius during the early life stages would be closely related to the movement of the Oyashio Water.