Biological aspects of the Ganges River sprat Corica soborna (Clupeidae) in the Mathabhanga River (SW Bangladesh)

Hossain M.Y., Leunda P.M., Ohtomi J., Ahmed Z.F., Oscoz J., Miranda R.

Date de parution: septembre 2008
Volume: 32
Number: 3
Pagination: 241-246
Editeur: Société Française d’Ichtyologie

The present study describes some biological parameters, including sex ratio, length-frequency distributions, size at sexual maturity, fecundity as well as length-weight (LWR) and length-length (LLR) relationship of the Ganges River sprat Corica soborna (Hamilton, 1822) (Clupeidae), an important target species for small scale fisheries in the Mathabhanga River in Bangladesh. A total of 135 specimens ranging from 30.6-48.9 mm TL (total length) and 0.22-1.20 g BW (body weight) were analysed. Sampling was done using traditional basket traps and funnel bag nets between January and December 2004. The sex-ratio showed no significant differences from expected value of 1:1 (χ= 0.07, p > 0.05). The size at sexual maturity (TL50) for C. soborna females was estimated to be 44.4 mm TL and the mean fecundity of the sampled population was 1,280 ± 870 eggs, ranging from 420 to 3,240. The allometric coefficient b values of the LWR indicated isometric growth (~3.0) for both males and females (2.946 and 2.968, respectively). The LLR analysis between TL and fork length (FL) showed a highly significant correlation in both sexes (r2 > 0.911, p < 0.001). The data presented in this study would be useful for the sustainable management of the Ganges River sprat fishery in the Mathabhanga River in Bangladesh and neighbouring countries.

Mots-clés: Bangladesh - Clupeidae - Corica soborna - Fecundity - Length-weight relationships - Mathabhanga River - Size at sexual maturity
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