Animals shellfish are invertebrates the body of which is rigid thanks to the shell which forms them. Shellfish are aquatic animals, except the wood louse which adapted itself to the ground life.
The animal is formed by stiff segments which replace the skeleton, because they are invertebrate animals. They are often classified near insects because they have an exoskeloten, antennas, and several pairs of legs.
The aquatic crustacean breathes by means of gills. Some, as the lobster, have a thorax and a tail which they can articulate to move in the water. The lobster has two claws which are of useful as it has to crush and to grab it's food. It has 5 pairs of legs to move.
Shellfish are equipped with two pairs of antenna which are of use to them for sensory instruments.
Both eyes rise on extensions and can be moved in a independently.
The food source of shellfish is filtering the water in the case of shrimp, or scavanging and the other food than they find in the bottom of the water for the crayfishe. They are animals which clean the water and the sea bed.
The lobster, the crayfish, the crab, the shrimp are used for our food and dining pleasure.
