World Bank assisted National Agricultural Research Project (NARP) - University of Port Harcourt
Abstract
A total of 135 specimens of Pagellus bellotti were randomly collected
from artisanal boats in August 2018. Study of sex ratio, gonad maturity
and size-structure of Pagellus bellottii is meagre in Sierra Leone, and
forms the basis of the present study. The study will contribute to
current knowledge and promote rational exploitation of the stock.
Length and weight were measured using a fish measuring board (cm) and
digital weight scale (g) respectively. Sex and gonad maturity were
macroscopically assessed. Results showed dominant males (71.9%) and
significant difference observed (1:2.6) and expected (1:1) female: male
sex ratios (p <0.05). Only 11.9% and 11.1% of male and female gonads
transcended to the developed stage (Stage IV). The length-frequency
distribution for combined sex was unimodal (modal class, 17cm-20.9cm).
Mean length and weight respectively were, 19.04\ub10.32cm and
98.85\ub15.08g for males and 17.43\ub10.54cm and 78.61\ub16.32g
for females. Growth exponent (b) for male, female and combined sex was
2.809, 2.928 and 2.850 respectively and the correlation coefficient for
all sex categories showed (r > 0.9). Indexes of condition were
greater than 1.0 (K > 1) for all sex categories. Results portrayed a
heterogeneous gender population of Pagelus bellottii and vast
similarity in reproductive strategies by both sexes. The fish comprised
of one size group and males may be growing larger than the females.
Growth pattern was near-isometric for females and negative allometric
for the males, and both sexes were in better condition (K >1.0). An
annual study could provide further insight