Diversity and distribution pattern of copepods in Palk Bay coastal waters of India

The aim of this study was to find the species abundance and composition of copepod zooplankton in four selected sites such as Karangadur, Thevipattinam, Athangarai and Mandapam in Palk Bay region during February 2022 to January 2023. There is no significant difference (P<0.05) in water temperature, salinity, DO and pH values between the sites during this study period. In this study, we have observed 46 species of copepods belongs to 30 genus, 20 families and four orders. The overall percentage of copepod species composition in the four collection sites was: Calanoida (58.7%), Poecilostomatoida (17.4%), Harpacticoida (15.2%) and Cyclopoida (8.7%). In Athangarai site, a maximum of 40 copepod species were recorded. In Karangadu site, 34 species, in Devipattinam site, 28 species and in Mandapam site only 25 species were observed. In calanoid copepods, Acartia, Calanopia and Temora was the dominant genus which representing three species. In Poecilostomatoida order, four families, seven genus and eight species were observed. Out of the seven genus, Corycaeus was the dominant genus which comprises two species such as Corycaeus crassiusculus and C. speciosus. In Harpacticoida order, six families, six genus and seven species were recorded. Among the six genus, Longipedia represents two species (Longipedia coronata and L. weberi). The order Cyclopoida, has only one family, two genus and four species. Among the genus, Oithona was the dominant genus which contains three species. Among the 20 families, Pontellidae was the dominant one includes six species.