Seasonality in some tropical harpacticoid copepods (Crustacea) from West African coastal river

Abstract

Studies on the occurrence and seasonality of some harpacticoid copepods (crustacean) from a West African coastal river were carried out.  An all year round sampling was made to cover the twelve months of the year, using plankton nets of 55µm and 100µm mesh sizes.  Three species of harpacticoid copepods were identified, namely:  Nannopus palustris, Diarthrodes cf major and Bryocampus minutes.  While Nannopus palustris showed peaks in the dry season months of January and February, Diarthrodes cf major and Bryocamptus minutes showed peaks in the rainy season months of July and August.  Thus these crustaceans exhibit seasonality due to dry and rainy season months in the tropical coastal waterbody.  The seasonal abundance of these zooplankton is very important to the pelagic clupeids such as the “bonga” fish, Ethmalosa fimbriata and Sardinella species which feed largely on them.