Bacteriological quality of some fishes and crab from rivers within Imo River Basin

Abstract

Bacteriological quality of diseased and apparently healthy fish and crabs from freshwater habitats within Imo River basin were investigated. Seventy seven, (20 diseased and 57 healthy) fishes: Clarias gariepinus, Clarias lazera, Oreochromis niloticus, Lates niloticus, Heterotis niloticus, Heterobranchus bidorsalis and crabs were examined physically for disease symptoms like necrotic lesions, fin and/or gill rot, abdominal dropsy and pop eye. Diseased and apparently healthy sample of each fish were asceptically dissected and samples of skin, gills and intestine of each sample were subjected to microbiological analysis using pour – plate and spread – plate techniques. The total aerobic heterotrophic bacterial and coliform counts of sample were determined using pour – plate technique as descried by Cheesbrough (1998). The findings of the study revealed that Gram – positive bacteria: Streptococcus faecalis, Staphylococcus aureus, Enterobacter aerogenes and Gram – negative species: Escherichia coli, Pseudomonas aeruginosa, Pseudomonas putrefaciens, Flavobacterium sp. Aeromonas sp. Proteus mirabilis, Proteus vulgaris Vibrio sp. and Myxococcus sp . were isolated from diseased fishes while Streptococcus faecalis , coagulase – negative Staphylococcus, Enterobacter aerogenes and Gram – negative species: Escherichia coli, Pseudomonas aeruginosa, Pseudomonas fluorescens, Flavobacterium sp. Aeromonas hydrophila and Vibrio sp . were isolated from healthy fishes. Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa , and Pseudomonas putrefaciens were isolated from crabs. This study revealed that heavy contamination of water bodies within Imo River basin affects the health of fishes and aquatic organisms. Keywords : bacteriological quality of fish and crab in Imo River basin Journal of Aquatic Sciences Vol. 21(1) 2006: 9-14