Of particular significance in Indo-Pacific mangrove areas is the mangrove, or mud crab, Scylla serrata, which is harvested for local consumption as well as commercially throughout its range. It may be harvested by hand picking, using a crab hook, nets, crab traps or pots, spearing, or long-handled scoop nets at night in combination with torches. Mud crabs are fairly large, and have a high yield of delicately flavoured meat. They are largely sedentary and have a restricted home range, so they are easily captured and are therefore susceptible to overexploitation (Brown 1993).

Mud crabs may be found on the mud among the mangrove roots, but they usually occupy burrows within the mud. They are especially confined to burrows when they are in the soft-shell stage of their moult cycle. This crab is an opportunistic, nocturnal feeder, scavenging whatever food is available, as well as preying on other crabs, barnacles and molluscs.

Another important crustacean found in Pacific mangrove forests is the mud lobster, Thalassina anomala. It is most common among the knee roots of Bruguiera, where it constructs conical mounds leading to a burrow system that penetrates to the water line. The mud lobster is not really a lobster at all in the usual sense of the word, but is rather a relative of the ghost shrimps of the genus Callianasa. Exactly how the mud lobster feeds is not known with certainty, but it probably strains food particles from the bottom of its burrow. Mud lobsters are widely harvested throughout the tropical Pacific, and a variety of techniques have been developed for catching them.