Spatio-temporal Distribution of Portunid Crabs within the Gulf of Mannar, Southeast Coast of India

Sahu, A.; Venkataramani, V.K.; Chandravanshi, S., and Chandran, S., 2024. Spatio-temporal distribution of portunid crabs within the Gulf of Mannar, southeast coast of India. Journal of Coastal Research, 40(5), 937–951. Charlotte (North Carolina), ISSN 0749-0208. To explore the variety of portunid crabs along the Gulf of Mannar coast, an intensive survey was conducted for 1 year from October 2021 to September 2022. The sampling was done biweekly, at four landing sites, i.e., Vedalai, Keelakarai, Therespuram, and Thiruchendur. The Gulf of Mannar has a rich diversity of portunid crabs, and bottom set gillnets are the primary method of capture. Twenty-seven species were recorded in the study area, representing five genera. The genus Charybdis recorded the highest number of species with 11 species, followed by the genus Portunus and the genus Thalamita with eight and four species, respectively. The genus Scylla and the genus Podophthalmus were represented by three and one species, respectively. To conduct the biodiversity assessment, the occurrence and abundance data of portunid crabs were collected for 12 months in all the selected landing centers in the Gulf of Mannar. The data collected were pooled together by month, station and season, which included summer (March-May); pre-monsoon (June-August); monsoon (September-November) and post- monsoon (December-February). From the collected occurrence and abundance data, 15 biodiversity indices were calculated using the PRIMER v7 computer software package.