Rusty Crayfish, thought
to be native to Ohio, Indiana, Illinois, Kentucky and Tennessee have been
introduced to many other north east and central states. The primary path
of introduction is thought to be through being used as live bait. However,
they are also sold to schools by biological supply houses. While most suppliers
include a warning not to introduce them into the wild, they are sometimes
given away to students. It is also possible, as with the red swamp crayfish,
that people hoping to develop a viable commercial harvest from local lakes
may have planted them.
The rusty crayfish does
not burrow, preferring to find cover among rocks, logs, and other debris
in pools or fast water streams. They feed on a variety of aquatic plants,
worms, snails, leeches, clams, aquatic insects, fish eggs and small fish.
Because they have a high metabolic rate, they tend to consume much more food
than native species. Although they have been observed eating the eggs of
bluegill, bass, and pike, the fact that they reduce the abundance and diversity
of aquatic plants and food such as mayflies, probably has a greater impact
on these species.
have also been sold locally in pet stores as aquarium species. It is very likely
that once they grow a bit and begin eating everything else in the tank they
may be released into the wild. Once introduced, control or eradication becomes
difficult, if not impossible. The best control is to prevent their introduction,
and educate the public about the threats they pose.