Thomas Metteef age 12 of Philadelphia, PA:

What are crustaceans?

In the animal kingdom the crustaceans are the crusty ones. The lobster is a crustacean so is the crab, Mr. Lobster lurks in his underwater cave, waiting to grab a passing fish, Mr. Crab keeps his pincers always ready to take a nip at your toe. These fellows are certainly crusty: crabby characters, And ‑ they both wear crusty coats, The family names Crustacea, refers to the crusty coats and not the crusty characters of these creatures,

For convenience the experts have sorted the animals into tribes and families, There are often many families in a tribe and there are different relatives in each family. The Crustacea family is part of the largest of all the animal tribes' It is the Arthropods. tribe$ meaning those with jointed feet. Its members outnumber all the other animals in the world by six to one,

To qualify as an arthropod, an animal must have special joints, Since he has no inside bones this is not easy. His soft inside body is supported in a tough outer coat. The joints are leathery rings where the rigid armor is bendable. Muscles attached to the inside straddle across these joints. The muscles can shrink and stretch and this is how an arthropod bends his joints, He may have five pairs of jointed legs jointed antennae and a jointed tail.

The soft body inside is filled with fluids. They are kept circulating by a simple heart. This heart is just a tube open at one end. It pumps away as fluids from the body drain into it through little pipes, The arthropod breathes oxygen though some may get it from the air and soma from the water. Air or water enters through holes in the armor along the arthropods sides. Of all places to have a nosei

By now you have guessed that the insect family is part of the Arthropoda tribe. Spiders and scorpions belong to another arthropod family and so do our crusty crustaceans. Our crusty ones are water breathing arthropods,

A crustacean must have all the qualifications of an arthropod, However he has important differences from an insect or a scorpion. His outer coat is usually made of a hard armor called chitin. The shell that covers his head and thorax is fused into one piece. He has no waist like a wasp, Most of the crustaceans have five pairs of legs and two pairs of antennae.

The giant of the family is the Japanese crab with a shell ten feet across. His smallest cousins are the water fleas that teem on the surface of the ocean. These midgets measure 100 to the inch and provide food for larger ocean dwellers: Most of the crabs are crustaceans, though not the king crab, Not all the members live in the ocean. Some enjoy life in swamps where the level of ground water is high. One of the cousins is very common in our streams, rivers, ponds and lakes. He is the crayfish, alias the crawfish a small fresh water copy of his big sea‑going cousins the lobster