21
Continental J. Agricultural Science 3: 21 - 26, 2009
© Wilolud Online Journals, 2009.
THE LENGTH - WEIGHT, LENGTH - LENGTH RELATIONSHIP AND CONDITION FACTOR OF Synodontis
resupinatus IN GBEDIKERE LAKE BASSA, KOGI STATE, NIGERIA.
*
Adeyemi, S.O,
1
Adikwu, A.I
1
and Bankole, N.O
2
1
Department of Biological Sciences, Benue State University, Makurdi.
2
National Institute For Freshwater, Fisheries
and Research, New Bussa, Niger State.
ABSTRACT
Length-weight, length-length relationships and condition factor of male, female and combined
sex of Synodontis resupinatus Gbedikere Lake Bassa, Kogi State was studied. One hundred
and forty three fish samples of total length ranging from 8.20cm to 16.60cm and weight
between 2.25g and 76.05g collected between July and December 2007 were analyzed. Results
showed that the isometric growth for male, females, combined sex and juveniles had
regression coefficient (b-value) of 3.02, 3.23, 3.13 and 2.19 respectively. Both male and
females exhibited positive allometric growth, juveniles on the other hand showed negative
allometric growth. The regression coefficient (b-value) for the length-length relationship was
1.5645, 2.8050, 1.9768 and 0.9668 for males, females, combined sex and juveniles body
growth respectively while the condition factor of all the sampled population varied from 1.03
to 2.55, females were in better condition than males and there was no significant difference
(P>0.05) between them. Gbedikere Lake is a good environment for growth, reproduction and
survival of the fish species.
Keywords: Length weight relationship, condition factor, Synodontis resupinatus, Gbedikere
Lake, Kogi State.
INTRODUCTION
Fish found in tropical and sub-tropical water system experience frequency growth fluctuations due to factors such as
food composition changes, environment changes, rate of spawning to mentioned but a few, length weight, and
length-length relationship can be used to assess the influence of these factors in fish. Kulbicki et al, (1993) and King
(1966) reported that fish growth, mean weight of a given body length of fish estimation and the relative well being
in fish can be known through this relationships, length-weight, length-length relationships studies have been done in
different water bodies and on different fishes. Notably among these are the report of King (1996) on some Nigerian
fresh water fishes, Taiwo and Aransiola (2001) on Chrysichthys species in Asejire Lake, Fafioye and Oluajo (2005)
on five fish species in Epe Lagoon, Nigeria and Laleye (2006) on Oreochromis niloticus in Oeume River in Benin.
Synodontis accounts for important part of the commercial catches in Northern Nigeria and, according to Reed et al,
(1967), they are available throughout the year. In the River Niger, Synodontis accounted for 18.00% by number and
18.68% by weight of total fish caught (Mortwani and Kanwai, 1970).
The study present information on the length-weight, length-length relationships and the condition factor of this
valuable fish species is in order to aid its management in the lake.
MATERIALS AND METHODS
STUDY AREA
Lake Gbedikere is a natural lake located between Latitudes 3
0
24
0
and Longitudes 5
0
14
E
and is about 10km to the
East of Oguma the Head quarter of Bassa Local Government Area of Kogi State.
Water enters the Lake from tributaries that run from River Benue during rainy or flood season. When the season is
over, the Lake separates out. The Lake is about 450m north of Gbedikere village. The water body covers about 400
– 450m and a depth of 10 – 14m deep, depending on the season.
The pond water is only used for fishing; consequently most of the settlers around the Lake are fishermen (Upper
Benue River Basin Development Authority, 1985). The lake experience two seasonal