ABSTRACT As a detritus consumer, the presence of fiddler crabs (Uca spp.) is related to the environmental condition, including the mangrove condition in that crab’s habitat. A research aims to understand the structure of fiddler crab community in the mangrove ecosystem in the Mengkapan mangrove ecotourism area was conducted in January – February 2021. There was 3 stations in the study area…