The Ecological Diversity and Distribution of Brachyuran Crabs in the Mangroves of Kalibhanjadia, Bhitarkanika National Park, Odisha

This study aims to investigate the diversity and distribution of brachyuran crabs living in the mangrove swamps of Kalibhanjadia Island, located within the Bhitarkanika National Park in Odisha, India. The research spanned two years, from January 2018 to December 2019. A total of twelve species of crabs from six distinct families were recorded. The families represented include Sesarmidae (Episesarma versicolor, Episesarma mederi, and Parasesarma plicatum), Varunidae (Metaplax dentipes, M. distincta, and Varuna litterata), Grapsidae (Metapograpsus latifrons, also known as M. maculatus, and M. messor), Ocypodidae (Uca annulipes and U. rosea), along with one species each from Gecarcinidae (Cardisoma carnifex) and Portunidae (Scylla serrata). The results reveal a clear distribution pattern of brachyuran crabs across varying salinity gradients, underscoring their ecological adaptability. Specifically, grapsid, sesarmid, and ocypodid crabs mostly inhabit riverbank regions with low to moderate salinity, while varunid crabs, with the exception of Varuna litterata, are predominantly found in areas characterized by medium to high salinity within the upper tidal zones.