Macroinvertebrate Fauna Of A Nigerian Freshwater Ecosystem

Abstract

A survey of macro invertebrate fauna of Anambra River was carried out for 22 months at Otuocha,Ogurugu and Nsugbe. The macro invertebrates were sampled using kick sampling technques and scoop nets. Sampled specimens were identfied to generic level. During the study a total of 21 genera of macroinvertebrates belongingto 13families were identified. The fauna was composed ofGyrinus sp. (29.2%), Macrobranchium sp. (19.6%), Ranatra sp. (13.2%) and Agabus sp. (3.5%). The margalef\'s index of fauna richness showed that Otuocha station had the highest species richness (12.70), followed by Nsugbe (7.01), and Ogurugu (6.80) stations. The least fauna diversity of 021 was registered at Nsugbe as against 3.15 at Otuocha and 0.86 at Ogurugu. The McNaughton community dominance index was more pronounced at Nsugbe (53.1) than at Otuocha (49.69) and Ogurugu (47.04). Jackson\'s fauna similarly index showed that the fauna at Otuocha and Ogurugu were more closely related (0.64) than the fauna at Nsugbe.

Keywords: Macroinvertebrates, Anambra River, Nigeria

Animal Research International Vol. 4 (1) 2007 pp. 611-616