Here we report novel data on the ecology and diversity of West African estuarine biological communities, with emphasis on the opisthobranch gastropod, Haminoea orbignyana. Macrofaunal samples were obtained from five intertidal flats within Bodo Creek in the lower Niger Delta during two years (May 2006–April 2008) to investigate diversity and community assemblages of epimacrofauna. A total of 601 individuals belonging to 18 species were recorded, with density varying between 4 ind.m−2 and 660 ind.m−2. Gastropods (predominantly Pachymelania aurita and H. orbignyana) accounted for 92.3% of the community abundance, followed by malacostraca crustaceans (7.7%). Diversity varied (P < 0.05) between locations, with the mangrove swamp station having higher richness, diversity and evenness values than the open intertidal flat locations. The species H. orbignyana was only found on downstream sampling sites reaching a maximum density of 52 ind.m−2. The species seems to recruit during November/December and likely attains a maximum life span of about 18 months.
