Graham's Crayfish Snake

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MDC Staff

Family:

Colubridae (nonvenomous snakes) in the order Squamata (lizards and snakes)

Description:

Graham's crayfish snake is a medium-sized, dull-colored, semiaquatic snake known from prairie streams, marshes, and ponds. The ground color is brown or yellowish brown above, with yellowish-tan stripes along the sides. There may be a faint tan stripe along the middle of the back. The belly is cream colored or light yellow, with a faint central row of gray or light brown dots and a zigzag pattern of dark brown along both edges. If captured, these snakes generally do not bite but usually release a foul-smelling musk mixed with feces.

Similar species: This and other snakes that live around water are often confused with the venomous western cottonmouth. The true cottonmouth is more heavy-bodied with a larger, chunky head; has a facial pit between the nostril and eye on either side of the head; is darker; and has a light line from each eye to the corner of the mouth. Also, no western cottonmouths are known to occur north of the Missouri River in our state.

Size:

Length: 18 to 28 inches.

Habitat and conservation:

Active from April through early November, this reclusive snake often takes shelter under rocks, logs, or in crayfish burrows along the edges of slow-moving prairie streams, marshes, sloughs, or ponds. In spring and early summer, it basks among branches overhanging water. In hot weather, it becomes nocturnal. In winter, it takes shelter in crayfish burrows. Like most other snakes associated with water, this species is often misidentified as a cottonmouth and needlessly killed.

Foods:

True to its name, this snake feeds mainly on freshly molted crayfish (which temporarily have soft bodies), as well as tadpoles and frogs.

Distribution in Missouri:

Statewide, except for the Ozarks.

Life cycle:

Mating occurs in April and May. This species bears live young instead of laying eggs. The young are born from late July through September. An average litter numbers 16 but may contain from 4 to 39 young. The coloration of juveniles is similar to that of adults.

Human connections:

Although, in its general color and appearance, this snake looks nothing like a cottonmouth, it is often misidentified as one and summarily slain. Crayfish snakes are harmless to us. Our many misconceptions about snakes arise from fear that we acquire at an early age. Knowledge corrects our prejudice.

Ecosystem connections:

As predators, crayfish snakes control populations of the crayfish and frogs they consume. As with many other predatory species, they can be preyed upon themselves by larger animals, including mammals and predatory birds. The eggs and young are especially vulnerable.