Crayfish can be found in
just about any body of fresh water which isn't overpolluted.
This includes streams, rivers, lakes, ponds, and sometimes
even water-filled ditches.
Crayfish are very common
in Northern Virginia, but they are difficult to identify.
There are three common genera:
Cambarus, Orconectes, and Fallicambarus. Most of our
crayfish are Cambarus.
Crayfish can usually be
found by turning over rocks in small streams and creeks; the
larger the rock, the larger the crayfish. Crayfish are
nocturnal,
so they do most of their hunting at night.
Copyright, Keith
Crandall
Copyright, John
White
Crayfish are Crustaceans, and are
closely related to lobsters, crabs, and shrimp. They have ten legs;
the front two have developed large claws called "Chellae." Be
careful! Crayfish are easy to catch, but a large one can pinch hard.
Crayfish use their chellae not only to defend themselves, but also to
attack prey,
move small objects such as stones, and to pick things up.
After crayfish mate, the female
carries a cluster of eggs attached to her swimmerets. Swimmerets are
the feathery things under the crayfish's abdomen. After the baby
crayfish hatch, they will stay on their mother's body for protection
until they are big enough to be on their own.
Crayfish are omnivorous,
so they eat both plants and animals. They are also scavengers
and will eat dead things, as long as they are relatively fresh. Some
favorite foods of crayfish are worms, insects, insect
larvae,
and the eggs of fish, frogs, toads, and salamanders.
Crayfish will create a home for
themselves under a rock or a bank by moving smaller items around.
They are agressive and defend their territories.
Larger crayfish dominate smaller crayfish. How big they get, and how
fast they grow, depends on many factors, such as water quality,
temperature, and how much food is available. When a crayfish is
threatened, it will escape by flipping its abdomen
and swimming backwards.
Crayfish have many
predators,
including raccoons, opossums, snakes, and muskrats.
Crayfish are a popular animal for
children to catch, and often the first "dangerous" animal they come
into contact with. Only very large crayfish can do any damage, but
even a smaller crayfish's pinch can hurt, so kids learn how to be
careful picking them up.
Many people eat crayfish. They are
also used by fisherman as bait.
Crayfish help humans in other
ways, such as cleaning up dead animal and plant matter from the
bottom of streams, and by controlling populations of insects and
other animals.
