what is crustacea ?

Question

what is crustacea ?

Answer 1

Crustacea is the only group of arthropods that is primarily marine, though there are many fresh water species also. There are some semi-terrestrial species, but these are not, in general, well adapted for life on land. In contrast with other members of the phylum Arthropoda, most notably insects, crustaceans have not been very successful on land. This can be attributed to a number of CONSTRAINTS.



However, Crustacea have exploited every habitat of the marine environment, and in so doing have become a very diverse group, from the very large Japanese Spider Crab (look at the specimen in the museum), to the tiny planktonic water flea Daphnia sp.



The Crustacea can be divided into six major groups and after a brief introduction to their common body plan, a description of each follows on the remaining unit pages. To revise Key Features refer to those listed in the Arthropoda unit.

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Answer 2

Crus·ta·ce·a

n. pl.

[Neut. pl. of NL. crustaceus pert. to the crust or shell, from L. crusta the hard surfsce of a body, rind, shell.]

(Zoöl.) One of the classes of the arthropods, including lobsters and crabs; -- so called from the crustlike shell with which they are covered.



Note: The body usually consists of an anterior part, made up of the head and thorax combined, called the cephalothorax, and of a posterior jointed part called the abdomen, postabdomen, and (improperly) tail. They breathe by means of gills variously attached to some of the limbs or to the sides the body, according to the group. They are divisible into two subclasses, Entomostraca and Malacostraca, each of which includes several orders.

Answer 3

A CLASS WITH LOBSTERS,CRABS, AND SHRIMP....