Diversity of reef fishes in hook and line fishery at Mandapam, Gulf of Mannar, southeast coast of India

Reef fishes landed by hooks and lines at Mandapam landing centre for a period of four years from October 2008 to May 2012 were studied based on fortnightly sampling. The hook and line fishing is seasonal in Gulf of Mannar and it last for six months annually from Oct-Nov to Apr-May as this area remains rough during the rest of the period. On an average 171 t/year was landed during the study period with a maximum of 295 t during 2008-09. After that the landings showed a decline. A total of 32 species of reef fishes belonging to 14 families were landed. Among them, Sphyraena barracuda contributed the maximum with a share of 42% followed by Caranx heberi (15%). Family wise landings indicated the dominance of Sphyraenidae (46%). Biodiversity studies were made using PRIMER 6 software. Different indices of conventional diversity as well as that of taxonomic distinctness based on dominance plot, dendrogram and funnel plots of delta+ and lambda+ are presented and discussed.