Definition, Characteristics, Evolution, Facts - Britannica crustacean, any member of the subphylum Crustacea (phylum Arthropoda), a group of invertebrate animals consisting of some 45,000 species distributed worldwide Crabs, lobsters, shrimps, and wood lice are among the best-known crustaceans, but the group also includes an enormous variety of other forms without popular names
Characteristics of crustaceans | Britannica crustacean , Any member of the 45,000 arthropod species in the subphylum Crustacea Distributed worldwide, crustaceans are distinguished by having two pairs of antenna-like appendages in front of the mouth and other paired appendages near the mouth that act like jaws
Crustacean - Aquatic, Arthropod, Exoskeleton | Britannica The Crustacea as a whole shows great variation in the number of somites and the amount of fusion that has taken place In the class Malacostraca , which includes the decapods, there is a consistent body plan: the trunk (which follows the head) is divided into two distinct regions, an anterior thorax of eight somites and a posterior abdomen of
Malacostracan | Definition, Characteristics, Examples, Classification . . . malacostracan, any member of the more than 29,000 species of the class Malacostraca (subphylum Crustacea, phylum Arthropoda), a widely distributed group of marine, freshwater, and terrestrial invertebrates Lobsters, crabs, hermit crabs, shrimp, and isopods are all malacostracan crustaceans
Crustaceans Portal | Britannica Crustaceans are a group of invertebrate animals consisting of some 45,000 species worldwide Crabs, lobsters, and shrimps are all counted among the subphylum Crustacea Crustaceans are found primarily in water, as noted by Sebastian the crab in Disney’s “The Little Mermaid” (1989)
Crustacean - Evolution, Paleontology, Adaptations | Britannica In classifying the Crustacea, a variety of characters are important: the form and extent of the carapace, if present; the number of trunk somites, or segments, and how many fuse with the head or with the telson; the number and degree of specialization of the trunk limbs; the presence or absence of paired eyes and of a caudal furca—i e , a
Shrimp | Types, Anatomy Habitat | Britannica shrimp, any of the approximately 2,000 species of the suborder Natantia (order Decapoda of the class Crustacea) Close relatives include crabs, crayfish, and lobsters Shrimp are characterized by a semitransparent body flattened from side to side and a flexible abdomen terminating in a fanlike tail The appendages are modified for swimming, and
list of crustaceans - Encyclopedia Britannica This is a list of significant crustaceans, which are members of the subphylum Crustacea They are grouped taxonomically by class, with notable members of each class ordered alphabetically (See also invertebrate; shellfish ) class Branchiopoda
Shellfish | Mollusks, Crustaceans, Bivalves | Britannica shellfish, any aquatic invertebrate animal having a shell and belonging to the phylum Mollusca, the class Crustacea (phylum Arthropoda), or the phylum Echinodermata The term is often used for the edible species of the groups, especially those that are fished or raised commercially