There are more than 375 species of crayfish found in the United States and more than 600 total known species in the world. Crayfish are found in a variety of different colors, including brown, white, grey, red and blue.
Crayfish are freshwater members of the crustacean family, which also includes shrimp, crabs and lobsters. Although crayfish are usually much smaller, they share most of the same body structures as lobsters. This includes their large, powerful claws, which are used for defense, catching prey and moving pebbles or other small items. One exception to this rule is the Shrimp Crayfish, which gets its name from the fact that it looks almost exactly like a shrimp.
In addition to being differently colored, another major difference between the various species is the shape and size of their claws. Some species have long and skinny claws, while Digger Crayfish and other species have extremely short and broad claws. Other species with notable claws include the strong, striped claws of the Bigclaw Crayfish and the weak, nearly nonexistent claws of the Shrimp Crayfish.
Despite their claws, crayfish are actually omnivorous and eat a quite varied diet consisting of aquatic and land plants, snails, fish and insects. They are also scavengers, as they frequently eat both dead plants and animals.