MEPS 282:253-260 (2004)  -  doi:10.3354/meps282253

ABSTRACT: Stage duration and growth rate during the late larval stage can be key parameters of recruitment dynamics in the Japanese anchovy Engraulis japonicus in the Kuroshio-Oyashio transition region of the western North Pacific. The developmental rate was defined as a reciprocal of the duration in days of the metamorphosing stage, and was a positive function of the growth rate after the onset of metamorphosis. The growth rate after the onset of metamorphosis in the early juvenile stage fish corresponded with higher growth rates in the early metamorphosing stage fish. The results indicate that larvae with a faster growth rate during the late larval stage metamorphosed at a younger age than the larvae with a slower growth rate. Developmental and growth rates were faster in the southwestern waters than in the northern and eastern waters in the Kuroshio-Oyashio transition region. Survival during metamorphosis depends on the developmental and growth rates, and we conclude that the larvae with faster developmental and growth rates in the southwestern waters had a higher probability of successful metamorphosis and recruitment to the spawning stock, and constituted the major part of the population of E. japonicus in the Kuroshio-Oyashio transition region.

KEY WORDS: Developmental rate · Growth rate · Otolith · Metamorphosis · Japanese anchovy