Ecology of benthic macroinvertebrates in the depositional biotope of a river in southern Nigeria

Abstract

The ecology of benthic macroinvertebrates was studied in the depositional biotope of a river in southern Nigeria in two contrasting tidally influenced fresh and brackish water stations. Forty five taxa in nineteen families representing seven major groups of benthos were recorded. The molluscan families, dominated by Neridae, Hydrobiidae were restricted to the brackish water station 2 while the insect groups Baetidae and Chironomidae dominated the fresh water station 1. The dominant families, Chironomidae and Hydrobiidae, which are primarily deposit feeders, accounted for 41.2 and 58.8% individual organisms. The distribution of benthos was significantly influenced by season and salinity. The composition, distribution and seasonality of benthos in the study biotope are discussed.