MANGROVE CRAB UCA SPP (CRUSTACEA: DECAPODA: OCYPODIDAE). In Indonesia, many found the river estuary waters with mangrove forests are an important area for mangrove crabs. Crustacean fauna of the mangrove ecosystem is dominated by the crabs of Uca spp. this is often found in mud, forest floor, ponds and mangrove logging areas. Uca spp. is a type of crab that live in holes or soaking in the substrate and are permanent residents of mangrove forests. Crab Uca spp. can adapt well to dig holes because the water that is in the hole can help regulate body temperature through evaporation. Uca crab has important body parts as characters for identification that are: the size of the face of carapace (rostrum), orbital area (the area around the eyes), gonopode (male), gonopore (females), large claws (male) and small claws. While large claws on an adult male is a key character, so that its is very important.