Diamond-backed Watersnake

One subspecies, Northern Diamond-backed Watersnake (N. r. rhombifer), occurs in the Mississippi and Tennessee River drainages in West Tennessee, and also known from the Cumberland River drainage in Stewart and Montgomery counties in Middle Tennessee.

Description: A large, keel-scaled, heavy-bodied snake (30.0 to 48.0 inches in length) with light patterns on the back that somewhat resemble diamond shapes.   These diamonds are created by dark brown chainlike markings extending over the body on a light brown or yellowish ground color.   

Belly is yellow with irregular rows of black “half-moons.”   Males have small raised bumps (papillae) under the chin.   Young are strongly patterned and have bright orange on their bellies.

Similar Species:  Cottonmouths are dark brown or black without the chainlike pattern on the back.

Habitat: Found in a variety of aquatic habitats, but usually in oxbow lakes, rivers, cypress swamps, marshes, and sloughs.

Diet: Eats slow-moving fish, frogs, toads, and salamanders.

Breeding information: Courtship and breeding occur in the spring. Males rub the small raised bumps under their chin along the backs of receptive females during courtship. Females give birth to 13-62 live young during the late summer or fall.

Status in Tennessee: Not a protected species. As with other watersnakes, Diamond-backed Watersnakes are misidentified as Cottonmouths and are needlessly killed.

Fun Facts:

  • Diamond-backed Watersnakes become more nocturnal as the weather becomes warmer.

Best places to see in Tennessee: Reelfoot Lake or any drainages of the Mississippi River in western TN.


Conant, R. and Collins, J. 1998. Peterson Field Guides: Reptiles and Amphibians (Eastern/Central North America). Houghton Mifflin Company, New York. 616pp.

Johnson, T.R. 2006. The Amphibians and Reptiles of Missouri. The Missouri Department of Conservation, Jefferson City, MO.