(also known around the United States as “crayfish”, “crawfish”, “mudbugs”, “yabbies”)
GUESS THE FOLLOWING QUESTIONS BEFORE READING FURTHER (answers at bottom)
TRIVIA #1: Do crayfish swim forwards or backwards?
TRIVIA #2: Crayfish with equal size claws are female or male?
TRIVIA #3: A crayfish will typically DOUBLE it's size with every molt - true or false?
Crayfish are omnivorous...similar to most shrimp and lobsters. That means they will eat almost anything. Crayfish eat fish, shrimp, water plants, worms, insects, snails, plankton, dead plants and animals, cat food and hot dogs. (what???) They hold their food with their claws and are generally very messy eaters.
They breathe through feather-like gills and are found in bodies of water that do not freeze to the bottom; they are also mostly found in brooks and streams where there is fresh water running, and which have shelter against predators.
With proper care, a crayfish can live two years in captivity (although in the wild, some species have been known to live 20-30 years.)
Over 350 species of the 500 crayfish species of the world live in the United States.
The most common crayfish gets 3-4 inches long, but they can get much bigger in the wild, esp. in deep lakes.
These crustaceans have good eyesight and, like other related species, they can move their eyes independently from one another.
Crayfish molt at the end of June. They usually eat their old skeleton in order to recover the calcium and phosphates contained in it. In fact, on the sides of their stomach, crayfish have two limestone grains, filtered from the water, which serve for impregnating the newly forming skeleton with calcium.
Crayfish walk forward; but swim backwards (usually to flee from a threat) by quickly curling and uncurling their abdomen and utilizing their spinnerrets. A speed of 5 metres per second (11 mph) has been recorded. This is known as the caridoid escape reaction.
During the breeding season, males fight for the right to copulate and, in these competitions, they may lose a leg or claw. This is no problem, as the claw or leg will slowly grow back.
Besides humans, water birds, pikes and eels indulge on crayfish. They are also extremely sensitive to diseases.
The presence of crayfish in the water is a sign of lack of severe contamination. Crayfish cleanse the water of detritus and carrion. Lake Baikal, the deepest in the world (5,371 ft depth), has unusually clear waters. This is due to tiny crustaceans (1,000 weigh 1 mg), which feed on the algae and bacteria that make the water bloom.
#1: They swim backwards, but walk forward
#2: males will have one claw larger than the other.