ICHTHYOFAUNA DIVERSITY AND MORPHOMETRIC ANALYSIS IN ANTHROPOGENICALLY STRESSED WATER BODY DOWNSTREAM OF JEBBA DAM, NIGERIA

Abstract

Fishery resources are on the decline due to incessant and unregulated tishery activties practtced in most parts of the globe. This study investigated the fish composton of an anthropogenically stressed vwater body in Nigeria (Downstream Jebba Dam). Samples were collected using standard methods and procedures. A total of 6,850 fish belonging to 17 famulies and 25 pecies were collected from the sampled stations. Fish composition shows the Mocho.dae famly wth the most dominant specics at 29.33%o and represented Synodontis batensoda, which was well distrbuted in all the study stations but highest in the station with 934 indıviduals, while the Gymnarchsdae family was the least recorded with 0.16% and represented Gymnanhus ntlotrus Length-Weght relationship (LVR) value ranged between 0.0018 8 and 0.215 (b <3) fior the domnant fish species, inicating negative allometric growth as the fish spccies grows in length taster when compared to the weight. In terms of mean condition factor (K of the dominant fish species of Downstream Jebba Dam, Gyuothrissa mento had the highest with 10.09, followved by Orocbramts nilotcns 9.82, Mugil cephalus (9.02), Labeo conbie (3.72), Bagyus bayad (0.90), Aestes marolepidotus (0.52). Caroe laticeps (0.31), Monyrus rune (0.26), Clarias gariepinus (0.19) and Citharinns atharus 0.16). The high condition factor (>1) observed in some fish indicates that these tish species were phystologicaly stable and successful well, while those with less than (<1) mean value implied that it was physiologically unstable, as showed in some species. Overall, the mediur abundance of fish species in this study is an indication of an impaired water system