Ecological Diversity of Marine Copepods of Mandapam Region, Southeast Coast of India

Presently, an evaluation was made on the spatiotemporal variation of physio-chemical characteristics of sea water, and biodiversity of the copepod was studied at the Gulf of Mannar Region, Southeast coast of India. The monthly surface water and copepod samples were collected from February 2021 to January 2022. The physico-chemical characteristics of water were analysed. The collected copepods were identified based on morphological characters, and the diversity indices of copepods were estimated. The findings of the study inferred that the rainfall ranged between 0.4 and 351.1 mm and chlorophyll “a” varied from 0.01 to 1.42 mg/cm3. Atmospheric and surface water temperatures were found to range between 26.64 and 30.34ºC and 26.0 and 30.83ºC, respectively. The chemical parameters, including pH, salinity, and DO, were varied from 5.33–8.47, 25.33–38.17%, and 0.05–5.43 mg/L, respectively. The inorganic nutrients such as ammonia, nitrite, nitrate, phosphate, and reactive silicate were 2-10.82 µmol/L, 0.11-1.95 µmol/L, 0.07-1.816 µmol/L, 0.31-9.27 µmol/L, and 2.04-61.56 µmol/L, respectively. A total of 34 copepod species were recorded; among them, calanoid contributed 12 species, while both cyclopoid and harpacticoid contributed 11 species, respectively. The Mandapam coastal areas with an abundant diversity of copepods denote the main role of ecological connection in Palk Bay, Indian Ocean, and Gulf of Mannar, India. The present study favours a continuous analysis with further investigation of the distribution and diversity of open ocean and benthic copepods and their ecological importance in the Gulf of Mannar coastal region, Southeast coast of India.