MACRO- INVERTEBRATES STATUS OF OLUWA RIVER IN ONDO STATE, SOUTHWEST, NIGERIA.
MACRO- INVERTEBRATES STATUS OF OLUWA RIVER IN ONDO STATE, SOUTHWEST, NIGERIA. The macro-invertebrate fauna of Oluwa River, Ilaje Local Government Area,Ondo State, Nigeria were investigated for eighteen months (June, 2014 – November,2015) covering both the rainy and dry seasons. The major objective of the study was to provide baseline information on aspects of the biology (taxonomic composition, occurrence, distribution and abundance) of the benthic macro-invertebrates. The benthic macro-invertebrates made up of seventeen species belonging to three phyla; Arthropoda, Annelida and Mollusca. They consisted of five classes: Crustacea, Gastropoda, Insecta, Oligochaetae and Polychaetae Altogether a total abundance of 2,264 individual macro-invertebrates species were collected from the bottom sediment. The gastropoda were the most abundant and constituted 50% of the total benthic macro-invertebrates organisms encountered in Oluwa River. Pachymelanin aurita had the highest percentage (12.9%). The least amongst this group was Lanistes varicus (5.1%). Polychaetae accounted for 27% of the total benthic macro-invertebrates organisms in Oluwa River. In conclusion, on the basis of benthic macro-invertebrate taxa composition and abundance, Oluwa River can be inferred to be rich in fauna composition and therefore fairly polluted. Keywords: Benthic macro invertebrates, abundance, Oluwa River, Ondo State
Francis Olaniyan (Primary Presenter/Author), University of Ibadan,Oyo state,Nigeria, email@example.com;
Alex Ugwumba (Co-Presenter/Co-Author), university of Ibadan, firstname.lastname@example.org;