Gulf of Mannar Island coral reef associated gastropods assemblages:Distribution and diversity pattern

Objective:To study the spatial and temporal variations of the distribution and diversity pattern of coral reef associated gastropods assemblages in Gulf of Mannar Island and to clarify the relationship between gastropods and surrounding coral reef ecosystem.Methods:Gastropods were collected from three islands-Hare(Picnic spot),Vaan(Church Island)and Koswari(Karsuvar Island).The samples were taxonomically identified according to external structure of typical shells and classified according to their feeding habits.Statistical tool Primer(Ver.6.1.11)was employed to find the species diversity,richness and evenness.Results:A total of forty species of gastropods from 19 families were identified.The gastropods population density varied differently at stations,479 species from Vaan islands,390 species from Koswari islands and 254 species from Hare island were recorded.The gastropods species diversity,richness and evenness indices also varied differently at stations.The highest species diversity indice was recorded at Vaan Island(2.968),while both the highest richness and evenness indices were recorded at Hare Island with 0.937 and 0.942 respectively.Conclusions:The results of present study provides useful informtation for biodiversity conservation as well as the management of coral reef habitat in India.