Aquatic Insects Diversity and Water Quality of a Tropical Freshwater in Federal University of Education, Ondo, Nigeria

Abstract

Aquatic insects are regarded as one of the very important components of the freshwater ecosystem because of the various ecological purposes which they serve. The insects are also the most impacted when surface waters are disturbed. As such, analyzing the structure of assemblage has become a veritable yardstick in the assessment of biodiversity and water quality. This research effort applied the combination of aquatic insect composition and physico-chemical characteristics in assessing the ecological status of Oju Awo stream. Aquatic insects and water samples were collected once in every two months covering a period between December, 2021 and October, 2022 using sweep nets and1L sterilized bottle respectively. The results obtained for the physical and chemical parameters of the water as well as the aquatic insect assemblage showed that the investigated reaches of the stream did not differ widely except for water temperature which showed significant variations (p < 0.05) along the reaches of the waterbody. A total of 242 aquatic insect specimens represented by three (3) orders (Hemiptera, Odonata and Coleoptera) and sixteen (16) taxa were recorded. Hemiptera was the dominant and most abundant taxa as it accounted for about 90.91% of the total insect collection. The dominance of pollution tolerant species, the absence of sensitive insects’ species and poor water quality as revealed by the physico-chemical parameters indicated deteriorating water quality conditions in the stream.