Growth and production of Donax Sordidus Hanley on an Open Sandy Beach in Algoa Bay

Abstract

A population of Donax sordidus (Mollusca, Pelecypoda) has been studied for two years on an open sandy beach. There were summer and winter settlements each year with the former being larger. Growth was rapid, the animals reaching 20 mm length within one year. Few live longer than 17 months. Production averaged 168,7 mg dry matter m^-2y^-1 and the steady state P¯/B¯ was 1,30y^-1. Energy values averaged 17,84 kJg^-1dry tissue and had a seasonal cycle with maximum values before spawning.