Distribution of recent benthic Ostracoda around, Appa Island, Gulf of Mannar, India

The present work reports the distribution of Ostracoda from the surface sediments around Appa Island in the Gulf of Mannar, Tamil Nadu, southeast coast of India. In total, 33 surface sediment and bottom-water samples were collected for this study. In the study area, 34 Ostracoda species belonging to 30 genera, 17 families, 4 superfamilies, 3 suborders, 2 orders and 2 subclasses have been identified. Distribution of species as abundant, common and rare, for every station is being recorded. Among the identified 33 ostracod species, 5 are abundant, 4 are common and the remaining 24 are rare. The total population is higher in the southern part of the island, whereas the northern part of the island has a lower population comparatively. The Ostracoda are indicative of high energy, oxygenated environments in the study area, not conducive for juvenile forms. The ratio of carapaces to open valves of Ostracoda indicates a relatively moderate rate of sedimentation.