The Effect of Birth Date on Growth of Juvenile White-spotted Charr Salvelinus leucomaenis

Abstract

An individual's growth opportunity may be influenced by the date on which it was born. To examine the effects of birth date on growth in juvenile (Age 0 +) white-spotted chart Salvelinus leucomaenis, individual birth dates were identified by counting the daily growth increments in the otolith. Significant linear relationships were found between fork length at catch and birth date; early-born individuals tended to be larger than late-born ones at a given time. About one quarter or half of the variability observed in fork length could be explained by birth date variation. Differences of birth date among individuals within a cohort may have a significant influence on later stages of life history, such as age at seaward migration.