Crustacea is the personality of a large group of organisms called arthropods or hewar a vertebra. There are over 38,000 species of crustasea. Examples of the type crustasea are shrimp, lobster, and crab. There are so many other crustasea species such as wood lice, water fleas, and keritip. Crustasea has a strong outer shell called the exoskeleton that is useful to protect the soft tissue. All types crustasea legs and body have vertebra.
Only a few crustasea who live on land. Crustasea generally live in water, several types of crabs can live on the beach even Robber crabs can climb trees. Crustasea started life as an egg. Eggs will hatch into tiny larvae, the larvae formed millions of plankton will float on the sea. Many larvae crustasea are not similar to the adult animal. Barnacle larvae is an agile swimmer. However, when the larva becomes an adult, he glue himself to a stone and would not move anymore. When the larvae grew larger, she discards discard its shell and grow a new larger shell. The process of changing the shell is called moulting. Crustasea continue to change shells throughout their lives. During the switch shell crab is vulnerable to enemy attack.
Crab, lobster, and shrimp are all decapod. A pair of front legs adapt to the claw. Claw is used for multiple functions, namely to defend themselves, catch and tear food. Claw is also used to signal to others.