I used to catch crawfish as a kid, but I don’t see them much anymore. Are they still around?

May 2007

Crayfish must molt to grow. Molting is also a time to repair injuries, allowing the regrowth of lost claws or legs. (Photo by Emmett Westbrook)

Crayfish must molt to grow. Molting is also a time to repair injuries, allowing the regrowth of lost claws or legs. (Photo by Emmett Westbrook)

Yes, these miniature lobster-like crustaceans are still hiding in creeks and mud banks, but they’ve taken a heavy hit. Non-native species, water pollution and dam building have dramatically decreased populations in the United States.

Called crawfish, crayfish, crawdads, mud bugs and ditch bugs, there are some 600 species of crayfish worldwide. Some are no bigger than the end of your finger. Others are the size of small lobsters. Colors and patterns differ to blend into local surroundings. A few species are eyeless, such as the cave-dwelling crayfish in Kentucky’s Mammoth Cave, which has also lost its color.

The southeastern United States is home to the world’s largest variety of crayfish, with about 40 species in North Carolina. Many of North Carolina’s crayfish are considered rare, and seven species are found nowhere else on Earth.

Crayfish live in just about every freshwater habitat – from lakes and rivers to ponds and roadside ditches. They are nocturnal, and some are more terrestrial than aquatic, digging burrows in marshes and wet fields. You might even find lumpy mud “chimneys” in your backyard.

Crayfish feed on snails, tadpoles, worms, fish eggs and dead plant or animal bits. To capture live prey, they sit in ambush with only their antennae moving to detect a passing meal. When a quarry wanders by, the crayfish snaps it up with its claws.

The crusty outer shell of crayfish protects its soft body, and, like their lobster cousins, their claws are used for capturing food and self-defense. They breathe with gills, and to evade predators they use a flip of their fan-shaped tail to shoot backward.

Crayfish mate in the fall, but females store the sperm until spring. They lay 10 to 800 eggs, depending on species, and attach them with sticky glue to swimmerets on their belly. The eggs hatch in a few weeks, but stay attached to the female for protection until the young go through their second molt. Crayfish molt 6 to 10 times their first year.

Crayfish have long been a popular food item. Otters, raccoons, herons, muskrats, snakes and fish like the crunchy snack, and humans eat them by the ton, either boiled, steamed or fried, as well as in soups, salads and pies.

No longer are all crayfish in our lakes and streams local. Exotic species have been introduced – both as escapees and accidentally – and are taking a toll on local species. In Europe, a crayfish from America brought along a deadly fungus that nearly wiped out local populations. In our state and many others, the aggressive rusty crayfish and red swamp crayfish have escaped from farms and fishermen and now threaten native crayfish which can’t compete.