Freckled Crayfish

Cambarus maculatus


Photo of a freckled crayfish.
The freckled crayfish is largely restricted to the Courtois Hills section of the Meramec River basin.
Chris Lukhaup
Species of Conservation Concern

Cambaridae (freshwater crayfish) in the order Decapoda (shrimp, crabs, and lobsters)


This powerfully built, yellowish-tan crayfish has numerous conspicuous black spots on its pincers, carapace, and abdomen. The freckled crayfish is distinguished from all other species within its range by the pattern of conspicuous black spots over the entire dorsal (top) surface. As with many Ozark crayfish, the river system it occurs in is a big clue for identification.


Adult length: about 2 to 3¼ inches.

Habitat and conservation

The freckled crayfish lives in the very clear, high-gradient, spring-fed streams and small rivers of the Meramec Basin. Rarely seen in the open, it digs burrows in gravel beneath large rocks and stays there, probably emerging at night to feed. Where it occurs, it is not as abundant as the other crayfish that live in the same streams.


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

Freckled Crayfish Distribution Map
Distribution in Missouri

This crayfish occurs only in the Meramec River basin of the Missouri Ozarks, especially the eastern and central areas of the basin, the Courtois Hills.


The freckled crayfish has a very limited range within Missouri and occurs nowhere else in the world (it is endemic to our state). It is a Missouri Species of Conservation Concern, since it is vulnerable to extinction. It was first described scientifically as a new species in 1988.

Life cycle

Mating probably occurs in the fall, and females have been observed carrying eggs in May. Apparently they carry eggs about a month later than do female spothanded, golden, and saddlebacked crayfish, which often occur in the same areas. Freckled crayfish apparently can live to about 4 years of age.

Human connections

Crayfish are eaten by many types of wildlife, including species that humans hunt and fish. Crayfish are fascinating, colorful creatures in their own right, and part of our rich native heritage. Species of Conservation Concern, such as this one, are protected from harvest by state law.

Ecosystem connections

Crayfish are an important link in the food chain between plants and other animals, breaking down plant materials that are resistant to decay. Crayfish in turn are an important food for many other animals. Presence of crayfish in a stream or pond usually indicates good water quality.