Distribution and Growth of Flathead Flounder Hippoglossoides dubius off Tohoku Area

Abstract

In order to disclose the life history of flathead flounder off Tohoku area, we investigated the distribution, age and growth from 1997 to 2001. The flathead flounder occurred in the continental shelf and up to 750m depth in the continental slope. Distribution of the fish shifted to the deeper area with growth. Growth difference was found between sexes as SL=227×(1-exp(-0.481×(1-0.311))) for male, and SL=366×(1-exp(-0.184×(1-0.257))) for female obtained through the age determination observing otolith section. Age composition estimated using age-length key for the five years showed significant increase of young fish in 2001, suggesting higher abundance of 1999 and 2000 year classes.