Impact of sand organic carbon and climatic changes on the population density and morphometric characters of Emerita asiatica in the East Coast of Southern India

Abstract

A population density of Emerita asiatica in relation to sand organic carbon in the Nemmeli beach, East coast, Kanchipuram District of Tamil Nadu was studied. Specimens were collected once in a fortnight from April 2017 to March 2018 by hand picking method in the intertidal region of Nemmeli beach. The total sand organic carbon level was recorded once in a fortnight. The population presented a smaller incidence of males in relation to females (48.66:51.34); however, in May 2017 an inverse pattern occurred (73:27). Ovigerous females were present in all samples with greater frequencies in October and November 2017 whereas, the highest juveniles were present in May and September 2017. The variation noted in a population of Emerita asiatica showed there is a relationship to sand organic carbon fluctuations; it can be determined that the sand organic carbon fluctuations have an influence on the population density of this species in Nemmeli beach. Hence, the rather stable sand organic carbon throughout the year and moderate changes in the sand may well be conducive to population biology of Emerita asiatica.