Temporal Variation in the Relationship Between Size, Numbers, and an Allele-Frequency in a Population of Mytilus edulis

Abstract

Shell-length and Lap-genotype were monitored in samples from a site off Orient Point, on the northeastern tip of Long Island, over a thirteen-month period. The changing relationship between Lap94 frequency and size was exploited to infer growth rates, times and nature of recruitment, and mortality characteristics. Specifically, growth appeared to total about 25 mm per year, being maximal in the summer; recruitment involved young mussels substantially larger than newlymetamorphosed spat; two episodes of recruitment of substantial numbers of 20-25 mm mussels are inferred. Death occurs mainly in the largest size-class, and the adult life span averages somewhat less than two years. The number of individuals on the site seems to remain remarkably constant, in spite of growth.