Plain-bellied Watersnake
Nerodia erythrogaster • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: N. erythrogaster
Found across the southeastern and central United States, from the Atlantic coast of North Carolina to the Florida Panhandle, west through the Gulf states to Texas and northern Mexico, and north through the Midwest to Michigan.
Look up Plain-bellied Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous
Danger Level
Harmless - low risk. While they may bite defensively if handled and secrete a foul-smelling musk, they pose no toxic threat to humans.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: N. erythrogaster
Conservation
Least Concern (IUCN). However, some populations, like the Copper-bellied subspecies (N. e. neglecta) in the Midwest, are federally listed as threatened due to habitat loss.
Physical Description
Dark brown to black or grey dorsal coloration. Heavily keeled scales are visible in the image. Although the belly (for which they are named) is typically solid red, orange, or yellow depending on the subspecies, this specimen appears quite dark. The head is relatively wide with large eyes and round pupils.
Size & Dimensions
Specimen in image appears to be a small juvenile or sub-adult (approx. 10-15 inches). Adults typically range from 24 to 40 inches (61-102 cm).
Habitat
Primarily semi-aquatic. Prefers river swamps, ponds, lakes, and marshes. Notable for spending more time on land than other watersnakes (Nerodia species), often found in woods or grassy areas near water.
Behavior & Temperament
Known for being quite defensive if cornered or handled; they will strike repeatedly and release musk. They are active both day and night depending on temperature and season.
Diet & Feeding
Primarily carnivorous, feeding on amphibians (frogs, toads, salamanders) and fish. They are active foragers that hunt both in water and on land.
Reproduction
Viviparous (gives birth to live young). Litters typically consist of 5 to 27 young, born between August and October.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with Cottonmouths (Agkistrodon piscivorus) due to their dark color and habitat, but can be distinguished by their round pupils, lack of heat-sensing pits, and different labial (lip) scale patterns.
Conservation Status
Least Concern (IUCN). However, some populations, like the Copper-bellied subspecies (N. e. neglecta) in the Midwest, are federally listed as threatened due to habitat loss.
Cultural Significance
Crucial for wetland ecosystem health by controlling amphibian and fish populations. Often misunderstood and killed by humans who mistake them for venomous Cottonmouths.
Notable Features
Highly keeled scales that give the skin a rough texture. Unlike most other watersnakes that stay close to the water's edge, this species is known for migrating significant distances overland during wet periods.