Ayaa Kojo Armah

Donax Pulchellus and Donax Rugosus on Sandy Beaches, Ghana Ayaa Kojo Armah

Donax species dominate the intertidal zone of coastal upwelling sandy beaches worldwide. The population dynamics of West African D. pulchellus and D. rugosus is still unknown. The population dynamics and ecology of surf clam Donax species, D. pulchellus and D. rugosus (Bivalvia: Donacidae), inhabiting two exposed sandy beaches of Ghana, were studied over 12 months period (August 2006 to July 2007). A total of 7,225 individuals of D. pulchellus, La beach and 2,452 individuals of D. rugosus, Chorko beach, were sampled. Two-way analysis of variance revealed a significant difference in the spatial and temporal distribution of the two species (p < 0.05). D. pulchellus attains first maturity at a mean length of 7.16 + 1.89 mm, and a maximum size of 11 mm while D. rugosus attains first maturity at a mean length of 20.94 + 6.98 mm, and a maximum size of 33.5 mm. Environmental factors namely, salinity, nitrate, and grain size modulate the growth in shell length of the two species. This book, provide new insight of Donax species as sedentary bivalves of sandy beach ecosystems. The book is useful for marine biologist, benthic ecologist, environmentalist, and chemical ecologist.