There are two forms of plain-bellied watersnakes in Oklahoma:

• Blotched water snake   (shown in all photos above)

Nerodia erythrogaster transversa

            The blotched water snake has dark blotches that run down the center of its back, with alternating spots down

            each side.

• Yellow-bellied watersnake

Nerodia erythrogaster flavigaster

Young yellow-bellied watersnakes have a pattern similar to the blotched water snakes.  Adults have no pattern or one that's very faint underneath the dark dorsal coloration.

The belly of both forms is yellow and there are dark markings on the outer edges of each belly scale.  The scales are heavily keeled, and the anal plate is divided. 

Size: 
Adults 30 - 48 inches (76 - 122 cm)

Prey: 
Fish, frogs, tadpoles, and salamanders

Reproduction: 
Mates April to June.  Females give birth to 5 - 25 babies in late summer and they are 7 - 12 inches (10 - 13 cm) long.

Habitat: 
Ponds, lakes, streams, rivers, wetland areas, and virtually any permanent body of water

Other Information: 
The blotched watersnake is found statewide except for extreme southeastern Oklahoma.

The yellow-bellied watersnake is found only in extreme southeastern Oklahoma.

Often confused with the venomous cottonmouth, this harmless snake is commonly seen basking on logs and rocks near water. When threatened it may emit a foul-smelling musk or even attempt to bite. When in the water, this snake will swim with the lower half of its body underwater and the upper half above the surface. (The cottonmouth swims with its entire body on the surface of the water)