The sediment characteristic and benthic macro-invertebrate fauna of some fish ponds in Ife north local government area (LGA), Nigeria

Abstract

This study investigated the sediment characteristics as well as the taxonomic composition of macrobenthic invertebrate faunae of some ponds in Ife north local government area,(LGA) Nigeria. The sediments were generally sandy, moderately acidic (pH range of 3.8 to 5.8) and well drained. The organic carbon of the sediment were within the usual range of 0.5 to 5% organic carbon while the nutrients (NO3-, PO43-, SO42-) varied from very low to moderate concentration in all the ponds. The failure for a buildup of organic material and nutrients to a very high level indicated that the wastes from the fish and exogenous feed were rapidly and completely broken down and thus does not develop to poor sediment characteristic. Macro-invertebrate fauna recorded were dominated by the molluscs typical of freshwater macrobenthic communities. Orders Architaeniaglossa and opisthobranchia were encountered with Melanoides (Melanoides) tuberculata of the order Architaeniaglossa being the most dominant taxon in the ponds. The abundance of pulmonates in these ponds showed that they were mesosaprobic – eutrophic water bodies that are slightly polluted and nutrient rich. Key words: Poor sediment, organic carbon, acidic pH, nutrients, macrobenthic invertebrate.