External Morphology

Chitinous carapace saturated in mineral salts, and covered in vesiculous granules. Bilaterally symmetrical, body is segmented into metameres. Each metamere bears a pair of appendages. Head has five pairs of appendages; antennules and antennae, each with a sensory function, mandibles maxillules and maxillae. Body comprises a thorax and abdomen. The body is divided into the frontal, hepatic and branchial regions, each of which bears these granules. Carapace defined by anterior lateral margin and posterior lateral margin, by which a transverse ridge separates. The orbit, which is one of two sections of the anterior margin on the carapace that opens to accommodate for an eyestalk, is bordered by spines on both side and fine grooves behind; grooves that mark the beginning of the hepatic region. The anterior lateral margin exhibits five to six small spines. Carapace is formed of the endocuticle soft layer, and the exocuticle which is the rigid outer layer. Carapace protects mechanically as armour, chemically and metabolically. Walking appendages, known as ambulatory legs, are segmented; dactyl, carpus, merus and propodus. The outermost of these segments, the dactyl and propodus are hairy. Chelipeds, which are the anterior claws, are asymmetrical. E. sebana exhibits discontinuous growth via moulting. This process is very complex, and can last anywhere from minutes to hours, and is a very hazardous process for the crab.