The global marine ornamental fish trade is a multibillion dollar industry. About 90% of the marine ornamental fish species are collected from the wild, mainly from coral reefs and adjacent habitats. Keeping this in view, a survey was undertaken to study the biodiversity of marine ornamental fish species with special reference to labrids (wrasses) in Gulf of Mannar. Of the 113 ornamental fish species recorded, 16 species belong to the family Labridae showing a rich biodiversity. Seasonal occurrence of labrids was investigated in five fish landing centres viz. , Thoothukudi, Vallinokkam, Mandapam, Vembar and Chinna Erwadi and six reef islands namely Kuswari, Villangu Shuli, Kariya Shuli, Nallathanni, Musal and Krusadai along the Gulf of Mannar coast. The study revealed that 11 species are distributed along Thoothukudi coast, followed by Vallinokkam coast (7 species), Mandapam coast (4 species) and Vembar (2 species). No labrid was recorded from Chinna Erwadi during the study period. Of the 16 species, Xyrichtys pavo , Cheilinus chlorurus and Thalassoma hardiwicki were recorded from all the 6 islands, whereas  Cheilinus undulatus was from 5 islands except Musal island. However, the remaining 11 species were observed only from 1 to 3 islands. From the study on food and feeding habits of labrids of Gulf of Mannar, it was learnt that they are carnivorous and feeding mainly on coral polyps, molluscs, crustaceans, fishes, polychaetes, seaurchin etc., showing their dependency over the coral reefs. Among the 11 species, X. pavo was found to occur in large numbers, constituting a minor fishery mainly along Thoothukudi coast. Asymptotic length (L) and Growth Co-efficient  (K) of X. pavo were estimated to be 42.53 cm and 0.27 respectively. Age and growth of X. pavo was also studied. Spawning and recruitment of X. pavo were found to occur throughout the year with a peak in April and August in the Gulf of Mannar.

 Wrasse, labridae, ornamental fish, Gulf of Mannar.