crustacean

/krəˈsteɪʃɪn/

/krəˈsteɪʃən/

Other forms: crustaceans

A crustacean is a member of a class of arthropods that live in water. Some of your favorite seafood comes from crustaceans — crabs, lobsters, and shrimp.

There are plenty of fish in the sea, and there are also plenty of crustaceans: strange-looking aquatic critters who usually have at least four pairs of limbs, plus a segmented body and a chitinous exoskeleton. If you think of a crust as being a little like a shell, that can help you remember crustaceans are essentially critters that have shells. Our word crust is from Latin crusta (shell or crust).

Definitions of crustacean

1. noun

   any mainly aquatic arthropod usually having a segmented body and chitinous exoskeleton
   types:

   malacostracan crustacean

   a major subclass of crustaceans

   decapod, decapod crustacean

   crustaceans characteristically having five pairs of locomotor appendages each joined to a segment of the thorax

   brachyuran

   typical crabs

   stomatopod, stomatopod crustacean

   a kind of crustacean

   branchiopod, branchiopod crustacean, branchiopodan

   aquatic crustaceans typically having a carapace and many pairs of leaflike appendages used for swimming as well as respiration and feeding

   copepod, copepod crustacean

   minute marine or freshwater crustaceans usually having six pairs of limbs on the thorax; some abundant in plankton and others parasitic on fish

   mussel shrimp, ostracod, seed shrimp

   tiny marine and freshwater crustaceans with a shrimp-like body enclosed in a bivalve shell

   barnacle, cirriped, cirripede

   marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces

   crab

   decapod having eyes on short stalks and a broad flattened carapace with a small abdomen folded under the thorax and pincers

   lobster

   any of several edible marine crustaceans of the families Homaridae and Nephropsidae and Palinuridae

   crawdad, crawdaddy, crawfish, crayfish

   small freshwater decapod crustacean that resembles a lobster

   hermit crab

   small soft-bodied marine crustaceans living in cast-off shells of gastropods

   shrimp

   small slender-bodied chiefly marine decapod crustaceans with a long tail and single pair of pincers; many species are edible

   prawn

   shrimp-like decapod crustacean having two pairs of pincers; most are edible

   tropical prawn

   edible tropical and warm-water prawn

   krill

   shrimp-like planktonic crustaceans; major source of food for e.g. baleen whales

   opossum shrimp

   shrimp-like crustaceans whose females carry eggs and young in a pouch between the legs

   mantis crab, mantis shrimp

   tropical marine burrowing crustaceans with large grasping appendages

   isopod

   any of various small terrestrial or aquatic crustaceans with seven pairs of legs adapted for crawling

   amphipod

   a kind of malacostracan crustacean

   daphnia, water flea

   minute freshwater crustacean having a round body enclosed in a transparent shell; moves about like a flea by means of hairy branched antennae

   fairy shrimp

   small freshwater branchiopod having a transparent body with many appendages; swims on its back

   Artemia salina, brine shrimp

   common to saline lakes

   tadpole shrimp

   a kind of branchiopod crustacean

   brit, britt

   minute crustaceans forming food for right whales

   cyclops, water flea

   minute free-swimming freshwater copepod having a large median eye and pear-shaped body and long antennae used in swimming; important in some food chains and as intermediate hosts of parasitic worms that affect man e.g. Guinea worms

   fish louse

   a kind of copepod

   Balanus balanoides, acorn barnacle, rock barnacle

   barnacle that attaches to rocks especially in intertidal zones

   Lepas fascicularis, goose barnacle, gooseneck barnacle

   stalked barnacle that attaches to ship bottoms or floating timbers

   type of:

   arthropod

   invertebrate having jointed limbs and a segmented body with an exoskeleton made of chitin
2. adjective

   of or belonging to the class Crustacea
   synonyms: crustaceous