Crustaceans                                                                                     home 
There are nearly 40,000 species of crustacea from the smallest microscopic plan tonic animals to the largest giant spider crabs having about a 10' or 5 metre leg span, and crayfish growing to around 40 lb or 20 kgs. Crustacean is also a common name for members of the mainly aquatic arthropod animals with jaws and two pairs of antennae, such as the crab, lobster, and shrimp.

Crustacean are also one of the most successful animals that dominat the sea, As much as insects dominate the land.

Crustaceans are found in every part of the oceans throughout the world from the shallow warm waters to the deeper cold waters. Their bodies are protected by a outer shell or skeleton.
Beleive it or not but barnacles, are crustaceans.

Usually crustacean have branched appendages but this is now not always true. They have a head, thorax and abdomen, and some have a tail this is used for swimming backwards.

Crustacean are the only arthropod with two pairs of antennae and the larger ones breath through gills; they also have three pairs of chewing appendages. Some also have their eyes on the end of stalks.

Some of the smaller crustacean such as the shrimps may be found amongst the tentacles of anemones and around sea urchins. This is two fold because the crustacean is able to eat food scraps and get some protection from the host.

The larger crustacean body skeleton serves as a suit or armour and helps protect them from predators such as eel's and other fish.

Having this outer body casing means that regularly they have to shed it to allow the animal to grow. This is done by the outer body splitting and the animal then squeezes out backwards leaving a smaller duplicate of itself.

When this happens the animal is soft and open to attack and so will seek out a hiding place during this time.

Some crustacean namely the crabs will seek out a old dead mollusc shell in which to live. They look for a shell that is just the right size so they have room to grow and latch onto it with special designed legs

Crustaceans are also play a major part in the food chain.

Some of them eat small plants and animals. Many of them strain small particles of food from the water, but the larger crustaceans such as shrimp and crabs are often omnivores, scavengers, or predators.

Several species are also parasites.

Crustaceans, in turn, are eaten by many animals, including us human beings, they are also rich in protein.

Any claws or legs lost on crustacean will re grow.