Preliminary Study On The Aspects Of The Biology Of Snakehead Fish Parachanna obscura (Günther) In A Nigerian Wetland|
Bolaji, B.B.; Mfon, T.U.__PS & __Utibe, D.I.
Between October 2000 and March 2001, a preliminary study on the aspects of the biology of Parachanna obscura, was carried out. Sex ratio revealed female preponderance (÷2 = 4.733, df = 1, P < 0.05). There was no variation in sex ratio during the wet season but there were more females than males in the dry season (÷2= 4.735, df = 1, p = <0.05). A curvilinear plot was delineated in the regression of the total length (9.0-18.0 cm TL) and total weight (5.6-40.11g TW), where TW = 0.018621 TL2.697, n = 408, r = 0.869, ([p<0.001). Trophic spectrum of P. obscura size range 9.0-18.0 cm comprises ten food items. The items were re-classified into seven major groups consisting of detritus [coarse and fine detritus], fish [juvenile and remains of fish], insects (un-identified adult and remains of insects, macrophyte materials, mud, nematode, and biogenic sand. Fish, insects and nematodes were eaten as primary food items. There was a complete ingestion of the array of the dietaries by both sexes of Parachanna obscura. Exception of one item (coarse detritus), during the wet season, Parachanna obscura consumed all the dietaries during the seasons. Nevertheless, the later season increased in the ingestion of nine out of 10 items in conformity with optimal foraging theory. Parachanna obscura is considered a piscivore-insectivore-invertivore in feeding habits. In the wake of doubt about the viability and prospects of aquaculture, farming of P. obscura could be desirable. This species possesses a number of positive attributes when it comes to aquaculture. It is likely that efforts to culture this hardy carnivorous and fast-growing fish will spread in the coming years in Nigeria, if breeders and fish farmers will give it a chance. Further studies are, however, required to delineate the full biology of P. obscura in order to highlight its viability for domestication and cultivability. P. obscura is widely enjoyed by natives of its natural habitats all over the world as a source of protein.
Parachanna obscura, Biology, Economic Potentials, Nigeria