Natural diets and length-weight relationship of Brycinus macrolepidotus in lower Ogun River, Akomoje, Ogun state

Abstract

The natural diets and length-weight relationship of Brycinus macrolepidotus in Lower Ogun River, Nigeria was studied. 124 fish samples were collected twice monthly from February-August, 2015 from catches landed by artisanal fishermen using cast nets and long line. The total length and total body weight of all fish captured were measured and then grouped into sizes. Length-weight relationship was determined using the formular W = aLb. Gut contents were determined using the frequency of occurrence and numerical method. Index of fullness was also determined. Result of stomach content suggests omnivorous feed habit as diet were of plant and animal materials. Stomach fullness was higher during the dry season and onset of the rains than at the peak of the rains. Mean total length and weight of specimens varied from 18.19 ± 1.59 cm and 71.21 ± 15.54 g (juveniles), 34.99 ± 2.80 cm and 142.25 ±34.05 g (sub-adults) and 24.45 ± 2.53 cm and 301.46±22.67 g (adults) respectively. Length-weight analyses showed negative allometry for all sizes (b