Ecology, Environment and Conservation Paper

BIOINDICES AND REPRODUCTIVE BIOLOGY OF BOMBAYDUCK, HARPADON NEHEREUS (HAMILTON, 1822) ALONG SUNDERBAN REGION OF WEST BENGAL, INDIA

V. Vinaya Kumar, A. Devivaraprasad Reddy, R. Avinash,R. Prasad Naik, Samuel Moses,T.S. Nagesh1 and Sudhir Kumar Das

Abstract

Bombay duck, Harpadon nehereus is a major contributor in commercially exploited fishery resources in India. Promising catches were landed from Sunderban region of West Bengal, having fresh domestic and dry export market value. The present study is dealing with aspects related with biology ofBombay duck, H.nehereus for the period of twelve months (August, 2008 to July, 2009) along Sunderban area of West Bengal. The range of hepato-somatic index varied from 0.254 to 0.452 and 0.345 to 0.796 for male and female, showing significant difference (P<0.05) between sexes and months. Gastro-somatic index reflects feeding intensity of fish. Significant difference (P<0.05) was observed in GaSI between sexes during different months. It was recorded the relative length of gut of fish,in the size group I (less than 260 mm total length) varied from 0.474-0.594 value with average of 0.524. But in size group II (more than 260 mm total length) the RLG value ranged between 0.500-0.602 with the average value of 0.544. The range of gonado-somatic index varied from 0.162 to 0.628 and 2.158 to 8.173 for male and female respectively. Significant difference (P<0.05) was observed between sexes and no significant difference was found between different months. The length at first maturity of female H.nehereus was observed to be 260 mm of total length. The minimum fecundity was recorded in length group of 210-220 mm (18,156) and that of maximum in length of 280-290 mm (92,012) size group. Current study yields up gradation of biological information of Bombay duck stock along North-East coast of India.