Structure and health status of the sand crab, Emerita taiwanesis Hsueh, 2015 from Sangchan Beach, Thailand: The histopathological approach

Although the impacts of environmental problems on aquatic organisms have been broadly reported in Thailand, the literature has not covered the sand crab, Emerita taiwanesis Hsueh, 2015. In this study, we focused on the structure and health status of E. taiwanesis, an economically important crab species, living close to human activity areas in Sangchan Beach, Rayong Province, Thailand. A total of 60 individuals were collected from the conservation and restoration of coastal resource project in Ban Rue Leg Kao Yod-based participatory during December 2016 - January 2017. We identified histopathological changes in the gill structure, but not in other vital organs, including ganglion, stomach, intestine, hepatopancreas and muscular bundles. The histological alterations in the gill include hematocyte infiltration, pyknotic nuclei and degeneration of pillar cells in the gill (50% prevalence), suggesting that the gill is a sensitive organ to environmental changes. Our observation provided a better understanding of E. taiwanesis morphology and its overall healthy state on Sangchan Beach. Additionally, we suggest that the sand crab would be a suitable sentinel species for monitoring the environment of coastal areas in Thailand.