Snake mackerel fishery of the Tuticorin coast of Gulf of Mannar with emphasis on population characteristics of the sackfish, Neoepinnula orientalis (Gilchrist & von Bonde 1924)

Snake mackerels form by-catch in deep sea trawls and gillnets with an annual average production of 106 t during 2004 - 2006 in Tuticorin area. Fishery occurred almost round the year with peak during November - March. Fishery and biology of the dominant species, Neoepinnula orientalis was monitored during 2004 - 2005. Peak spawning and recruitment of the species was during December - March period. Growth parameters, L∝ and K are estimated as 31.6 cm and 0.68/year respectively. K value indicates that fish growth is relatively slow. Natural mortality estimate (M) is 1.38, total mortality (Z) 1.59 and fishing mortality (F) 0.21. The exploitation ratio (E) is low being 0.132. These estimates indicate that the stock is at its early stage of exploitation and have large scope for future commercial exploitation. As a preliminary step in this direction, the extent of stock abundance, biomass and distribution of the stock needs to be assessed. Being a slow growing species in cold habitat, considerably long time is required for stock multiplication. These factors have to be taken into consideration while planning for exploitation of snake mackerels in future