ASSESSMENT OF MACROINVERTEBRATES OF LAKE GERIYO, YOLA, ADAMAWA STATE, NIGERIA

Abstract

Macro-invertebrates composition of Lake Geriyo, Yola, Adamawa State, Nigeria were investigated from January to December, 2019. Macro-invertebrates samples were collected from three different sites using Van Veen Grab method. Three phyla of macro-invertebrates were encountered in the Lake. They were Arthropoda represented by nineteen genera such as Ameletus, Callibaetic, Baetis (Ephemeroptera); Diura, Ostrocera and Leuctra (Plecoptera); Hydrobius, Agabetes and Stelelmis (Coeloptera); Macrostermum, Hydroptica and Setodes (Trichoptera); Chaobrus, Simulium, Chelifera, Odontomesa and Chironomus (Diptera); Ischnura(Odonata)Hesperocorixa (Plecoptera); Annelida represented by four genera such as Biomphalaria , Volvata, Bulinus and Helisoma; Mollusca represented by six genera such as Eclipidrilus, Stylodrilus, Isochaetidefreyi L, imnodrilus, Potomothrix and Tubifex. A total of 993 macroinvertebrates were recovered. Twenty-nine taxa were recorded. The higher number of taxa (28) were recorded at site II and III. The abundance of individuals was highest at site III. Arthropoda have the highest percentage composition (68.49%) by number followed by Annelids (20.04%), while Mullusca was the least (11.48%) by number. Variations in distribution of these organisms could be as a result of differences in local environmental conditions. All the macrobenthic invertebrates represented were pollution-tolerant and clean water species.