Ecological survey of freshwater ecosystems of Ovia, Edo state Nigeria for gastropod molluscs

The survey for freshwater snails in streams, rivers and a lake in Ovia Southwest LGA of Edo State, Nigeria was carried out from June to November, 2013. Samples were collected by using sweep-net and by hand picking of snails within the open water habitat, at marginal areas and on submerged vegetation at edges of the habitats. A total number of 579 individual snails belonging to 6 families, Ampullariidae ( Lanistes varicus ), Mutelidae ( Aspatharia subreniformis ), Thiaridae ( Melanoides tuberculata ), Bulimlidae ( Bulimulus  teniussimus, Drymaeus multilineatus ), Bithyniidae ( Gabbiella humerosa ), Hygrniidae ( Monacha catiana ) were collected. In terms of number and distribution, the Lanistes varicus was the most dominant species consisting of 258(44.6%) of the total number of snails collected. 330(56.9%) number of snails were collected from the open water, 209(36.1%) in the marginal areas and 40(6.9%) on submerged vegetation. Keywords : Freshwater snails, Ampullariidae, Mutelidae, Thiaridae, Bulimlidae, Bithyniidae, Hygrniidae, Submerged vegetation, Ovia, Edo State, Nigeria