Seasonal Changes In Hydrographic Factors And Breeding In Two Populations Of Crassostrea Tulipa
The seasonal changes in breeding activity of two populations of Crassostrea tulipa (Lamarck) in Ghana, and some hydrographic factors of their brackishwater habitats were investigated between February 1988 and April 1989. Temperature and pH were relatively stable and their fluctuation patterns were similar in both habitats. Transparency and salinity fluctuations were less apparent in the lagoon, but a distinct seasonal pattern occurred in the estuary where high and low regimes corresponded with the dry and wet seasons, respectively. The variations in dissolved oxygen concentrations did not fit a well-defined seasonal pattern in both water bodies. The oysters bred continuously in the lagoon while the reproductive activity was seasonal in the estuary where the non-breeding season coincided with the period of low transparency and salinity. However, there was an apparent lack of direct relationship between individual hydrographic factors and the breeding of oysters in the lagoon.