Population Ecology on the Yellowtail Seriola quinqueradiata in the Coastal Area of Japan. III. Growth of the Yellowtail Seriola quinqueradiata in the Japan Sea Coast in Recent Years.

Abstract

This paper deals with 815 samples of vertebral centrum of yellowtail caught in the Tsushima Warm Current area. Consequently, the following results were obtained: first, the rings of the vertebral centrum of young yellowtail appear between January and May. Second, the growth of yellowtail caught in the Tsushima Warm Current area in recent years is similar to that of fish caught in the Pacific Ocean in the mid-1960's. It is better than the growth of yellowtail caught in Wakasa Bay and Tsushima Islands around 1960. Third, the growth of young yellow-tail shows considerably different trends among coastal areas. That is, the growth in southern areas is better than that in northern areas, at least between the ages of one and three years old. Finally, the local groups of young yellowtail are expected to be more or less independent of one another among the coastal areas. Consequently, the present paper proposes the following hypothesis: the difference in the growth of young yellowtail results from the difference in temperature between the areas.