International Journal of Marine Science, 2016, Vol.6, No.24, 1-8
1
Research Article Open Access
Length–Weight Relationship, Condition Factor and Sex-ratio of Fish Fauna in
Badagry Creek, Lagos, Nigeria
Adeboyejo O. Akintade
, Clarke O. Edwin, Ekele A. Simon
Department of Fisheries, Lagos State University, Lagos, Nigeria
Corresponding email
International Journal of Marine Science 2016, Vol.6, No.24 doi
Received: 06 Mar., 2016
Accepted: 01 Jun., 2016
Published: 01 Jun., 2016
Copyright
© 2016 This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Akintade A.O., Edwin C.O., and Simon E.A., 2016, Length – Weight Relationship, Condition Factor and Sex-ratio of Fish fauna in Badagry creek, Lagos,
Nigeria, International Journal of Marine Science, 6(24): 1-8 (do
Abstract
This study investigated the condition factor, growth pattern and sex ratio of fish species from Badagry creek, Lagos
lagoon complex, Nigeria. A total of one thousand and eight specimens (1008) belonging to twelve (12) species were studied. The
total length ranged from 12.85±1.54 – 27.49±4.75cm, and body weight ranged from 38.50±14.04 – 159.09±28.24g with
Marcusenius
senegalensis
having the highest and
Oreochromis
niloticus
having the least. All the fish species examined showed positive
allometric growth (b > 3) except
Marcusenius senegalensis and Gymnarchus niloticus
. 478 male and 530 female specimens were
caught representing 47.42% and 52.58% of the fish population respectively, giving the overall sex ratio of 1male:1.1 females.
Keywords
Fish biology; growth pattern; Badagry creek; condition factor and sex ratio
Introduction
Fishes are one of the cheapest sources of protein in the world which contains necessary and essential nutrition for
body. Due to increasing population in all countries, fish may play an important role in economic development of
countries in both aquaculture and the production of ornamental fish. No other group of invertebrate serves man in
so many forms as fishes. Morphometric analysis provides a powerful complement to genetic and environmental
stock identification approaches (Cadrin, 2000), length-weight relationships allow the conversion of
growth-in-length equations to growth-in-weight for use in a stock assessment model. Information about individual
body weight-length/width relationships in populations is important for estimating the population size of a stock,
specifically for the purpose of its exploitation.
The Lenght measurement is aimed at comparing body shape in fishes as well as the relationship existing between
these measurement in different species. These measurement include total lenght, standard lenght, body depth e.t.c.
From the lenght – weight relationship, it is possible to determine whether the growth is isometric (that is, whether
the lenght and weight of the fish are increasing at a proportional rate rate to the other) or allometric (that is,
whether the increase in lenght is relative with increasing body size). The condition factor expresses the relative
degree of robustness or wellbeing of fish and reflects the degree of nourishment and state of sexual maturity. Sex
of fish, age of fish, type of fish species, maturity stage and season are some of the factors that influence the
condition factor of fish, leading to variation in the condition factor (Anyanwu
et al.,
2007; William, 2000).
The assumption of the condition factor is that fish in better condition are heavier (Bagenal and Tesch, 1978). It
also provides information on the physiological state of fish relating to fish welfare from the reproductive and
nutritional perspectives and also provides useful information that can be used as age, growth and feeding intensity
indices (Oni
et al.,
1983).
Condition factor (K-factor) provides information when comparing two populations living in certain feeding density,
climate and other conditions (Weatherly and Gills, 1987). Thus, condition factor is important in understanding the
life cycle of fish species and it contributes to adequate management of these species, hence, maintaining the
