The devil, or coffin cutter crayfish, and the chimney crayfish are two species of burrowers that live in non-permanent water, or semi-aquatic conditions. They are known for building elaborate chimneys where there is heavy, low lying soil, especially near ponds and streams. They are commonly found in wet meadow environments, near farm ponds, on levees, in irrigation ditches, and even on golf courses and residential lawns. Crayfishes burrow down to the water table, which in some situations, can be more than 14 feet underground.
Crayfishes have two main body parts - the head and chest region, which is called the cephalothorax.....and the abdomen. The part of the crayfish which is often referred to as the tail is actually the abdomen. It contains a unique muscle structure that allows the crayfish to swim backward very rapidly through the water.
They have two large pincers, or claws which extend forward of the thorax. The claws can be regrown if lost, and primarily fulfill three roles: feeding, mating, and fighting.
Excluding the claws, crayfishes have four pairs of walking legs. The first two pairs of walking legs are tipped with small pincers which the crayfish uses for grooming, food manipulation, and movement.
The eyes of the crayfish are on stalks which extend above the head to provide a wide view of its surroundings. Each eye comprises thousands of tiny structures, each functioning like a separate eye in multi-tiled fashion to give the crayfish a mosaic view of its world, much like that of an insect.
The two antennae and shorter antennules are used for touch and smell.
Crayfishes come in a variety of stunning colors, shapes and sizes. Dwarf crayfishes, for example, rarely grow larger than an inch, or weigh more than a fraction of an ounce, while the red swamp crayfish can grow to 6 or 7 inches, and weigh around 2 ounces.
The hard outer shell, or exoskeleton of the crayfish is made of calcium carbonate extracted from the water and secreted in layers. This limestone suit of armor helps provide protection against predators.
If you're interested in acquiring a DVD of the program, America's Crayfish: Crawling in Troubled Waters, check out our DVD Gallery.
Scientists refer to crayfishes as "keystone species" because they play a key role in aquatic ecosystems, and serve as a vital link in the food chain.
The Smithsonian Institute offers a comprehensive dictionary with a Species Index listing non-scientific names usually associated with discrete crayfish species in a downloadable PDF file.
The different kinds of food sources that are eaten by crayfishes, and ultimately packaged as the animal itself, are channeled up the food chain to fish, and non-fish species such as bullfrogs, turtles, birds, racoons, and otters. In fact, there are very few animals that venture near, or live within a stream that don't eat crayfishes, including humans.
Also known as crawfish, crawdad, and mudbug, the crayfish is a freshwater crustacean which belongs to an important group of aquatic animals called decapods. That means having ten legs, and the group also includes shrimp, crabs, and lobsters. Crustaceans all have segmented bodies, outer shells, or exoskeletons, and paired, jointed limbs.
One of the richest diversities of crayfishes found in the world occurs in the United States, east of the Rocky Mountains, where some 320 species inhabit a wide range of freshwater environments, including lakes and streams...springs, swamps, and even underground waters, or aquifers where the elusive cave crayfish is sometimes found.
Crayfishes, like fish, breathe through gills, but they can live extended periods of time out of water as long as their bodies are damp, and their gills are wet. The average lifespan for crayfishes is about three years, although some cave crayfishes may live for a decade or more.
Crayfishes can reproduce after they reach three to six months of age depending on food availability and water temperature. They typically produce young once a year at the beginning of the growing season; it is an activity which is based on the climate where they live. In the northern part of the United States, mating occurs in the spring and summer months, whereas in the southern part of the country, it occurs during the cool months.
All crayfishes, crabs, and shrimp grow by shedding, or molting their exoskeletons. During the molting period, crayfishes are called softshells because their exoskeleton is somewhat soft and rubbery, but it soon hardens to its normal condition, which is when they are called hardshells. Molting is a very stressful time for crayfishes, during which they are most vulnerable to predation, and pollution. Crayfishes molt many times from when they are hatched through the first year of life, but as adults, they will molt only once or twice per year.