Crayfish Report

Crayfish are close relatives of the Lobster and resemble a small shrimp. They live in freshwater habitats in North America and Europe.

The Crayfish has a joined head, thorax, and a segmented body. They range in colors for yellow, green, red, and brown. Crayfish are around 3 inches long.

The Crayfish has two pairs of sensory antennae. The eyes are all long pieces of skin that allow the eyes to move. The appendages of the thorax have four pairs of walking legs which are also used to help find food. Crayfish also own one pair of pinchers, which used for cutting, capturing food, attack, and defense. The crayfish also has several pairs of food handling "legs," bailers to cycle water over the gills, and five pairs of swimmerets which are under the abdomen. All of these legs can grow back if broken off.

Crayfish have a hard outer skeleton. This exoskeleton provides protection and allows movement, but limits growth. As a result, the crayfish regularly gets too big for its skeleton, sheds it, and grows a new larger one. This is called molting and it can happen six to ten times during the first year of rapid growth. For a few days following each molt, crayfish have soft exoskeletons and are more vulnerable to predators.

Crayfish often conceal themselves under rocks or logs. They are nocturnal animals and they feed largely on snails, algae, insect larvae, worms, and tadpoles. Adult Crayfish are active from dusk to dawn, and young crayfish are active from dawn to dusk. Their movement is always a slow walk, but crayfish also use rapid flips of their tail to swim backwards and escape danger.

Most crayfish have short life span that is less than two years. Crayfish have high-volume reproduction with a short gestation period, is important for the species to survive. The Crayfish mating season is from October to November, however the egg doesn't become fertilized until the spring. The predators of the Crayfish include alligators, burbots, chicken turtle, painted turtle, otters, and grackles.

Like all crustaceans, a crayfish has a fairly hard exoskeleton that covers its body. As shown in the diagram on the next page, its body is divided into two main parts, the cephalothorax and the abdomen. The cephalothorax consists of the cephalic (or head) region and the thoracic region.

The part of the exoskeleton that covers the cephalothorax is called the