Diversity assessment of benthic macroinvertebrate communities in Banco National Park (Banco Stream, Cote d'Ivoire)

In the present study, a first inventory of benthic macroinvertebrates in the Banco Stream, Cote d'Ivoire, and the correlations between environmental variables and taxonomic richness were analysed. Seven stations were sampled monthly over a 1-year period, using a hand net (10 similar to X similar to 10 similar to cm, 250 similar to mu m mesh, 50 similar to cm length). One hundred and thirty-two macroinvertebrate taxa were recorded. These taxa were distributed among 74 families and 15 orders belonging to Insecta (118 taxa; 89% of total richness), Oligochaeta (seven taxa), Crustacea (five taxa) and Mollusca (two taxa). KruskalWallis test revealed significant difference (at least P similar to<similar to 0.05) in macroinvertebrate richness between upstream stations (S1 and S2) and stations S4, S5 and S6. Chironominae and Tanypodinae (Insecta) were the two very frequent taxa in all the stations. Lumbriculidae (Oligochaeta), Desmocaris trispinosa (Crustacea) and Eurymetra sp. (Insecta) were frequently found in the samples. Hierarchical cluster analysis revealed three groups of sampling stations according to taxonomic similarity. Taxonomic richness was significantly and negatively correlated with conductivity, while it was significantly and positively correlated with substrate types (woody debris and gravel). Due to the fact that Banco stream is the locality type of an endemic shrimp species (Macrobrachium thysi), this basin is of high conservation priority.