Gray-Speckled Crayfish

Photo of a gray-speckled crayfish.
Scientific Name
Faxonius palmeri (formerly Orconectes palmeri)
Cambaridae (freshwater crayfish) in the order Decapoda (shrimp, crabs, and lobsters)

The gray-speckled crayfish is gray or grayish-tan with numerous greenish-black speckles and blotches on the pincers, carapace, and abdomen. A pair of large blotches are present near the back of the head, and another pair occur near the junction of the carapace and abdomen. The fingers often have conspicuous cream-yellow tips. The carapace is not separated at its middle by a space (areola). The gray-speckled crayfish is the only common Faxonius in the southeastern lowlands. Other typical crayfish of the region have longer, more slender pincers, and none have the pattern of dark paired blotches described above.


Adult length: about 1½ to 2½ inches.

Where To Find
Gray Speckled Crayfish Distribution Map

This crayfish occurs widely in the lowlands of southeastern Missouri and penetrates into adjacent sections of the Ozarks along the major streams.

The gray-speckled crayfish is restricted to permanent-flowing waters in ditches and streams, occurring among submerged tree roots and around logs and other organic debris, and beneath roots and rocks, often along banks. It does not seem to occur in swamps, sloughs, and natural lakes. It comes out into the open at night and hides by day. It sometimes constructs short burrows into the banks, or sometimes the bottom, of streams.

Crayfish are generally omnivores, eating a wide variety of plant and animal materials.

Life Cycle

Most adults molt in late summer through fall, after which males are in breeding condition. The breeding season continues through spring. In about March or April, males revert to the nonbreeding condition, and females produce eggs. Egg-carrying females hide in areas of deep debris or beneath rocks. The young do not become completely independent of the female until after their third molt. Some can reach adult size by August; others overwinter as juveniles and mature the following spring.

Crayfishes are unusual animals by some human standards. Human civilization tends to ask the question, "What is this animal good for?" expecting an answer involving economic value or monetary profit. But one proud tradition in American philosophy responds: They are "good for themselves, and we need not begrudge them their share of life."

Crayfish are an important link in the food chain between plants and other animals, breaking down plant materials that are resistant to decay. They are an important food for many animals that occur around or in water, including fish, snakes, turtles, wading birds, raccoons, and mink.

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Similar Species
About Aquatic Invertebrates in Missouri
Missouri's streams, lakes, and other aquatic habitats hold thousands of kinds of invertebrates — worms, freshwater mussels, snails, crayfish, insects, and other animals without backbones. These creatures are vital links in the aquatic food chain, and their presence and numbers tell us a lot about water quality.