Diversity and Community Structure of Benthic Insects in Fish Farm Ponds in Southern Côte d’Ivoire, West Africa

Abstract

Aims: The aims of this study were to determine diversity and community structure of benthic insects in fish farm ponds. Study Design: Monthly samplings have been conducted from December 2007 to November 2008 in five fish farms (Layo, Banco, Azaguié, Anyama I and Anyama II) in southern Côte d’Ivoire. In each farm, sediments were collected in three ponds using a van Veen grab. In each pond, environmental variables such as transparency, temperature, pH, dissolved oxygen and conductivity were measured in situ. Methodology: Samples were taken in six replicates which were pooled to constitute a sample for each pond. Results: A total of 31 taxa belonging to 18 families and 7 orders were recorded. Benthic Insects fauna is clearly dominated by Chironomid Diptera. Nilodorum fractilobus, Chironomus imicola, Stictochironomus sp., Tanypus fuscus and Ceratopogon sp. were the dominant taxa. Anyama II station recorded the maximum values of Shannon-Wiener diversity index and evenness. Insect community structure was visualized using Canonical Correspondence Analysis to show the affinities of each species for selected environmental parameters. Conclusion: The species reported for the first time contributed to the list of insects’ species from Ivorian aquatic ecosyste