MORPHOMETRY AND DIET OF Chrysichthys nigrodigitatus (Lecepede) IN MAJIDUN RIVER, IKORODU, LAGOS STATE, NIGERIA.

Abstract

The study was conducted to investigate the sustainability and availability of Chrysichthys nigrodigitatus one of
the most commercial fish found in Majidun River, Ikorodu between October, and December 2020. Fifty (50), fish
specimens were collected from fishermen at the landing site, the major fishing methods employed by the fishermen
were cast netting and set netting. The total length ranged from 11.00 to 30.00cm (mean size 19.67 ± 4.56cm) while
the standard length ranged from 8.30 - 24.50cm (mean size 15.09 ± 3.39cm). The length weight relationship was
described by the equation: Log W = 1.6373 + 2.88 LogSL and the condition factor ranged from 1.49 – 3.60. The
results were obtained from the study of the stomach contents of the specimens in the laboratory using visual and
microscopic examinations. Analysis of the stomach content were done by combination of frequency of occurrence
methods and numerical methods were used to study the food. The diets revealed five (5) identified food items and
unidentified mass. Sediments was the most abundant food items by occurrence (34.70%) followed by unidentified
mass (19.80%) while crustaceans, molluscs, fishes, and insects were the least abundant with 17.82%, 16.83%,
6.93% and 3.92% respectively. Considering the numerical method, mollusks was the most abundant (97.4%),
while insects was the least (0.23%).