Figure 23.30: Two Segmented Body Plans The bodies of crustaceans and insects are divided into three regions, the head, thorax, and abdomen. (A) In crustaceans, each body region bears specialized appendages, and a shell-like carapace covers the head and thorax. (B) The thorax of insects bears three pairs of legs, and in most groups, two pairs of wings. Unlike other arthropods, insects have no appendages growing from their abdominal segments.