Survey of the present and fast disappearing fish species along two rivers in the Niger Delta

Fisheries resources are on the decline in Nigeria due to over exploitation and inadequate management of her coastal waters. For sustainability of these resources, an adequate knowledge of species composition, diversity and relative abundance of her water bodies must be understood and vigorously pursued. A survey was conducted to determine fish species diversity in Brass and Nun River, Niger Delta, Nigeria and the socioeconomic studies carried out to determine the status of endanger or level of disappearance of fish species study area. The survey identified 53 species from 18 families caught from Brass and Nun stations respectively. The fish diversity from typically freshwater fishes such as Tilapia and Clarias to brackish species such as Chrysichthys nigrodigitatus and Penaeus species. The most abundant family within catch were the Scianidae, Cichlidae and Clariidae. A checklist of economically important fast disappearing fish species along the two water bodies was generated. Oil spillage, discharges from industries (industrialization) and the domestic wastes from boundaries settlements (urbanization) and farming activities along the tributaries were among the factors identified to have contributed to low species diversity and fast disappearance of certain species. Data generated from this study would serve as baseline information for fisheries resource management

Helminth parasites in freshwater fish species from Jebba Lake and Bida Floodplain areas of River Niger, Nigeria

A total of 610 freshwater fish specimens comprising 7 scaly fishes (Sarotherodon, Oreochromis, Tilapia, Marcusenius and Brycinus) and 6 non-scaly catfishes (Clarias, Chrysichthys, Synodontis arid Physailia) belonging to 7 families and 9 genera, from Jebba Lake and Bida floodplain areas of River Niger, Nigeria, between June 2004 and May 2006, were sampled and examined parasitologically for helminth parasites. Nine species of 1331 helminth parasites comprising five nematodes Eustrongylides africanus, Procamallanus laeviconchus, Spironoura petrei, Cucullanus bavlisi and an unidentified species; cestodes Proteocephalus ambloplitis and Wenyonia virilis keinjii, and two trematodes Oiplostomum tragenona and Euclinosiomum heterostomum were obtained from 198 infected fishes. The distribution of the helminth parasites were 48.4%; 35.6%; 15.1 %; 0.3%; 0.2% and 0.1% respectively in the intestine; pyloric caeca (stomach); muscle; liver and gills, gut and kidney. There was statistically significant difference (P < 0.05) between the infection rate and sexes of the fish species. The examined fish population shows that the female fish species were more infected than the male. Higher infection rate, mean intensity and abundance were found in female than in males and statistically insignificant (P > 0.05).the nonscaly catfish species were more proned to helminth parasites infestation than the scaly fish species; this might be due to morphological features. The study was carried out to provide information on the types, check list and problems of helminth parasites affecting the freshwater fish species from Jebba Lake and Bida floodplain areas of River Niger, Nigeria in order to create awareness to fish handlers and/or culturists and to facilitate monitoring them when and if they occur in aquaculture