Question

What common traits do organisms share in group Crustacea?

Answer 1

Crustaceans are characterised by a hard exoskeleton, jointed legs and a bilaterally symmetrical segmented body.

Explanation:

Main features of crustaceans are :

• a hard exoskeleton made up of calcium.
• the head has two compound eyes, two pairs of antennae and
  three pairs of mouth parts.
• a pair of green glands excrete waste near the base of antennae.
• the abdominal segments have swimming legs.
• the sexes are separate
• the tail is fan shaped and ends in uropod and telons.
• the circulatory system is open. There is no heart and the blood is
  pumped into sinuses instead of a closed loop.
• the nervous system consists of a primitive ventral nerve cord and
  ganglia system.

Most crustaceans live in water, but some live on land. There are about 30,500 known species of crustaceans around and he world.