IDENTIFICATION CHARACTERISTICS OF CRUSTACEANS
The crustaceans purchased for troop issue by DOD are defined as exoskeletal.
The body is covered with a hard outer shell that is divided into segments that are joined
together (for example, shrimp and spiny lobsters). Shrimp and spiny lobster have the
same basic anatomical structure. It is important that the food inspector be
knowledgeable of the anatomy of shellfish as each has a bearing on specification and
product utilization. In the case of oysters, the entire body is eaten. Only the flesh of
peeled and deveined shrimp is retained; the rest is discarded. More shrimp are bought
by the military services than any other of the shellfish.
ANATOMICAL FEATURES OF SHRIMP
a. External Features of Shrimp. The external features of a shrimp consist of
two major parts--the head, which is discarded, and the tail, which is saved. See Figure
(1) The head. The head contains the antennae, horn, eyes, and walking
legs. The head section is inedible because it contains 75 percent of the natural
bacteria. Since heads have no food value, they are usually removed at sea and
(a) Antennae. Antennae are sensory organs much like the nerve
under the lateral line of fish.
(b) Rostrum. The rostrum is a horn-like structure above the eyes that
has no particular function.
(c) Walking legs. The walking legs are used for movement on the
Figure 2-5. External Features of Shrimp.