Life tables for two field populations of soft-shell clam, Mya arenaria , (Mollusca: Pelecypoda) from Long Island Sound

Life tables were constructed for two populations of Mya arenaria from Long Island Sound, USA, based on schedules of age-specific fecundity and mortality determined under natural conditions. Mya arenaria shows a basic conservatism in general life history pattern. In both populations, fecundity increases with increasing female size; sexual maturity is attained at 1 year of age; a single annual breeding season occurs and survivorship curves approximate the type III of Deevey, which is characterized by extremely heavy mortality early in life followed by relatively constant mortality thereafter. Differences in the age-specific parameters for the two populations exist, however, for clams greater than 1 year of age, both age-specific fecundity and survivorship are significantly higher in the Stonington population.