Ray fishery by trawlers off Chennai and some aspects of biology of the scaly whipray Himantura imbricata (Bloch & Schneider, 1801)

Kizhakudan, Shoba Joe and Mohanraj, G and Batcha, Hameed and Rajapackiam, S (2010) Ray fishery by trawlers off Chennai and some aspects of biology of the scaly whipray Himantura imbricata (Bloch & Schneider, 1801). Journal of the Marine Biological Association of India, 52 (1). pp. 92-95.

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Abstract

Rays are important components in the elasmobranch landings by different gears at Chennai fisheries harbour, contributing about 75.4% to the annual average elasmobranch landings. The annual average catch of rays during 2002-‘07 was 588.3 t and the maximum catch of 1297.4 t was recorded in the year 2002. Eleven species contributed a major portion to the landings of rays by trawlers at Chennai, among which Himantura jenkinsii dominated the catch, forming 38.6% and H. imbricata, 8.0%. The disc width (DW) range of H. imbricata in the landings was 110-229 mm and 130-289 mm for males and females, respectively. The annual average mean size was greater in females. The annual average sex ratio (M:F) was 1:1.11. The disc width-weight relationships were W = 0.00022DW2.676 and W = 0.00005DW2.965 for male and female, respectively. Analysis of covariance showed that the slopes differed significantly, at 5% level, between the sexes. More than 95% of fishes sampled were in wellfed condition. Analysis of gut contents revealed H. imbricata to be a benthic carnivore feeding mostly on small crustaceans, cephalochordates, molluscs, polychaetes and small fishes.

Item Type:Article
Uncontrolled Keywords:Chennai; ray fishery; Himantura imbricata; disc width-weight relationship; gut contents
Subjects:Elasmobranch Fisheries
Demersal Fishes > Ray fisheries
Divisions:CMFRI-Madras (Chennai)
ID Code:5841
Deposited By:Geetha P Mrs
Deposited On:29 Oct 2010 16:52
Last Modified:12 Jul 2011 13:29

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