Life History traits of Silver Roughy Hoplostethus ntediterraneus (Cuvier) (Family: Trachichthydae) from the Continental Slope of South West Coast of India

Abstract

Distribution, abundance, sex ratio, food and feeding, maturation and spawning and length-weight relationship of Hoplostethus mediterraneus (Cuvier) inhabiting the continental slope of south west coast of India were studied. The data for the present study was collected from the deep sea exploratory fishing surveys conducted onboard FORV Sagar Sampada in the Arabian sea between 7° N latitude and 14° N latitude during 1999 - 2002. H. mediterraneus was found to be distributed in the depth range 280 - 682m. Depth wise distribution was found beyond 300m and at 8° to 10° N, it was found only in the depth zone 301 - 400m. While at 11° to 13° N, its occurrence was registered only beyond 400m. It showed a wider bathymetrical distribution (300 - 682m) in the latitude 10° -110 N. Length related chi square analysis of sex ratio in H. mediterraneus revealed that males skewed in all length groups as well as in all seasons. Spawning season of H. mediterraneus coincided with pre-monsoon and monsoon seasons. Feeding intensity was found to be very less and found to be feeding on myctophids, Aristeus spp., Heterocarpus spp., squids etc. LWR obtained for the depth zones 301 - 400 m and 401-500 m are Log W = -1.06 + 2.3 Log L and Log W = -0.88 + 2.12 Log L respectively