exoskeleton, that protects and supports the muscles and organs within, and many rigid appendages that are adapted to a variety of purposes, including swimming, crawling, and attacking prey Most edible crustaceans are “decapods,” meaning they have five pairs of legs, one of which is sometimes greatly enlarged into claws The meat of crustaceans is mainly skeletal muscle like that of fish and our land livestock (Notable exceptions are the immobile barnacles, prized in Spain and South America.) Because they’re mobile, carnivorous, and often cannibalistic, crustaceans aren’t as easy to farm as molluscs The greatest success has come with the shrimps, thanks to their ability to grow rapidly on both plant feeds and very small animals Crustacean Anatomy All crustaceans share the same basic body plan, which can be divided roughly into two parts The forward portion, or cephalothorax, often called the “head” in shrimp, is the equivalent of our head and trunk put together It includes the mouth, sensing antennae and eyes, five pairs of manipulating and crawling appendages, and the main organs of the digestive, circulatory, respiratory, and reproductive systems The rear portion, or abdomen, usually called the “tail,” is mostly a large, meaty block of swimming muscle that moves the fin-like plates at the back end The major exception to this body plan is the crab, which seldom swims; its abdomen is a thin plate folded up underneath a greatly enlarged cephalothorax The most important organ in the crustacean is what biologists call the midgut gland or hepatopancreas, and what the rest of us usually call the “liver.” This is the source of enzymes that flow into the digestive tube and break down ingested foods; it’s also the organ in which fatty materials are absorbed and stored to provide energy during molting ...portion, or cephalothorax, often called the “head” in shrimp, is the equivalent of our head and trunk put together It includes the mouth, sensing antennae and eyes, five pairs of manipulating and crawling appendages, and. .. The most important organ in the crustacean is what biologists call the midgut gland or hepatopancreas, and what the rest of us usually call the “liver.” This is the source of enzymes that flow into the digestive tube and break down ingested foods; it’s also the. .. of manipulating and crawling appendages, and the main organs of the digestive, circulatory, respiratory, and reproductive systems The rear portion, or abdomen, usually called the “tail,” is mostly a large, meaty block of swimming