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.: Home > Nature and Science > 2010 > Volume 8 Number 3 > *EMMANUEL B.E, GBESAN, K and OSIBONA, A.O

Morphology, Fecundity and diet of Galeoides decadactylus (Pisces: Polynemidae) (Bloch, 1795) off Nigerian coast

Department of Marine Sciences, Faculty of Sciences, University of Lagos Akoka, Lagos, Nigeria.
Abstract :


Galeoides decadactylus  (Bloch) is one of the three species of the family polynemidae 
commonly called the threadfins, found in warm tropical surface water of the Atlantic on the continental 
shelf of West Africa. They are important in the trawl fisheries of Nigeria. The specimens used for this 
study were collected off Nigerian coast from Lagos to Calabar between December, 2003 and 
November, 2004. In this study the length-frequency distribution, length - weight relationship, condition 
factor, sex ratio, fecundity, food and feeding habits of  Galeoides decadactylus were examined.  
Measurements recorded for each fish were standard length (SL) and total length (TL) to the nearest 
1mm and weight to the nearest 0.1g. Sexes of fish were determined by visual and microscopic 
examination of the gonads. Fecundity was estimated from the ripe ovaries (stage v) by the gravimetric 
method. The Gonadotropic Index (GI) and the Condition Factor (K) were calculated. Food items were 
quantified by two methods, the numerical and frequency of occurrence methods. The total length of 
259 specimens examined ranged between 12.0cm and 28.3cm (standard length 9.9cm to 20.8cm).  
Specimens exhibited negative allometric growth.  The condition factor increased with individual size.  
Females had a slightly higher condition factor than males.  The sex ratio was 1:0.46 (male:female). The 
number of eggs per female ranged between 58 001 and 279 279.  There was a negative correlation 
between log-fecundity and log-weight than between log-fecundity and log length.  The major food 
items were crustaceans, molluscs, pisces and annelids.  There were no distinctions in the feeding habits  of the species in relation to size.  The fish was euryphagus species and highly fecund. 
[Nature and Science 2010;8(3):15-23]. (ISSN: 1545-0740).
Keywords :
Galeoides decadactylus, fecundity, allometric growth, condition factor, euryphagus

Date Deposited : 12 Jan 2011 15:08

Last Modified : 12 Jan 2011 15:08

Official URL:

Volume 8, Number 3, March 2010 , ISSN 1545-0740

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