RELATIONSHIP BETWEEN BASIC MORPHOMETRIC MEASUREMENTS AND CROSS CARCASS VARIATION IN THE BODY PARTS OF TRUNK FISH (MORMYRUS RUME) FROM AGAIE- LAPAI DAM, NIGER STATE, NIGERIA

Abstract

A total of 91 Mormyrus rume specimen of various sizes were collected from Agaie – Lapai dam (Niger State) Nigeria, fourth nightly using gill nets, hook and line and cast nets, to evaluate the relationship between basic morphometric measurements, growth pattern, proximate composition of the whole body and cross carcass variation in its body parts using length weight relationship (LWR), condition factor (K) and laboratory analysis. The result of the basic biometric measurement of the specimens showed that Mormyrus rume from Agaie–Lapai dam had mean standard length of 34.08±3.28cm, total length of 37.71±3.57cm with a corresponding body weight ranges between 279.25-520g. The growth pattern analysis depicted that the fish was negative allometric with b value of 2.57 and condition factor “K” ranged from 0.73 – 1.21 with a mean value of 1.00±0.09. The results of the whole body proximate composition and cross carcass composition of its body parts showed that there was an inverse relationship between the body lipid and moisture in the whole body composition and that moisture was highest in the fish body in October and lowest in July while lipid was highest in June and lowest in October. Cross carcass variation of various parts of the fish showed that moisture ranged between 56.67-70.49 and was significantly higher in the fillet than other regions examined, the crude protein value ranged between 17.83-25.26% and the skin had the highest significant value, the lipid and ash ranged from 7.29-10.32% ;and the ash ranged from 2.02-6.40%, while the head region having the highest significant value in both the lipid and the ash values. It could be concluded that the M. rume of Agaie-Lapai depicted a strong significant correlation between the length and weight and the growth exponent “b” indicated a negative allometric growth pattern with a (K) value index above 1. Proximate analysis showed that the lipid and moisture were inversely proportional in the body of the fish while other nutrients in the body of the fish did not fluctuate significantly over time and nutrients were not evenly distributed among the body parts.