Distributions and habitations of African Pike Hepsetus odoe (Bloch, 1794), in Oba Reservoir, Ogbomoso, Nigeria (Actinopterygii: Hepsetidae)

Abstract : Population size structure of Hepsetus odoe was investigated during the rising and falling water levels in Oba Reservoir, Ogbomoso, Nigeria. The species was common in grassy, middle and open water microhabitats. The studied fish exhibited a wider size distribution in terms of space and time; the size of adults H. odoe changed from rising water means of 220.7 mm (S.D=28.2) to a falling water means of 216.9 mm S.D=51.6, t(long-transformed S.L)=30.32, D.F=132, P<0.0001. Also, all variables pertaining to males and females in microhabitats were significantly different (p<0.05). The sex ratios for inshore and offshore catches deviate from the same pattern as the deviation was significant in inshore and insignificant in offshore. Majority of the sampled fish inhabited inshore (56.4%), 46.62% occupied middle part and the total mean catch in micro habitats (grassy, middle and open waters) was less than 500 kg. The total mean catch for gillnets selectivity based on mesh sizes was less than 600 kg. Catch per unit effort (CPUE) increases with increased in fish size which correlates with increased net mesh size
Keyword : Hepsetus, Population size structure, microhabitats, inshore and offshore
Author(s) : , M. A. Adedokun, O. O. Fawole
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