Journal of Environmental Biology

Biological parameters of a silurid catfish Ompok bimaculatus

(Bloch, 1794) from River Ghaghara, India

S.K. Mishra¹, U.K. Sarkar^1*, S.P. Trivedi², J.I. Mir¹?and A. Pal¹

¹National Bureau of Fish Genetic Resources, Lucknow - 226 002, India

^2?Department of Zoology, University of Lucknow-226 007, India

*Corresponding Author email : usarkar1@rediffmail.com

 Publication Data

Paper received:

20 March 2012

Revised received:

27 November 2012

Re-revised received:

02 April 2013

Accepted:

25 April 2013

Abstract

The present study examined a total of 446 samples of Ompok bimaculatus and describes the condition factor, gonadosomatic index, length-length relationships, sex ratio, size at first maturity. The regression parameter ?b? ranged from 3.06 to 3.76 (r²?> 0.90). During the pre-monsoon, the allometric coefficient ?b? of the LWR was close to isometric value (b = 3.06) while that of overall was positive allometric (b = 3.31) although it suggested positive allometric growth in monsoon (b = 3.21), and post-monsoon (b = 3.76), periods. The values of condition factor ranged from 0.524 to 0.573. In the study, sex ratio ranged from 1:1.03 to 1:1.3. Males ranged from 14.0-26.6 cm while females varied from 11.2-29.0 cm in length. A significant difference in length at 50% maturity (p < 0.05) was found between both the sexes. First maturity stages in males and females were 22.3 cm and 23.2 cm, respectively. The smallest mature female was 22.0 cm L; the largest immature female was 26.8 cm L. The smallest mature male was 20.0 cm L; the largest immature male was 24.5 cm L. The results of the study could be useful to help in sustainable fisheries management in the Ghaghara River.

Key words

Ghaghara river, Ompok bimaculatus, Reproductive potential

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