Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
North America. Found throughout the eastern and central United States, and southern Ontario and Quebec in Canada.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous (Aglyphous)
Danger Level
Harmless; while they are non-venomous, they are famously defensive and will bite repeatedly if handled, causing superficial scratches and bleeding due to anticoagulant properties in their saliva.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
Least Concern (IUCN). Extremely common throughout its range, though often killed by humans due to confusion with venomous species.
Physical Description
Thick-bodied snake with keeled scales. Coloration is typically dark brown, tan, or grayish with reddish-brown or black crossbands near the head and alternating blotches on the back and sides further down. Based on the photo, dark vertical labial bars (lines) on the lip scales are visible, which is a key diagnostic feature.
Size & Dimensions
The specimen appears to be an adult or sub-adult based on the head proportions. Typical adults range from 24 to 42 inches (60-107 cm) in length; maximum recorded is approximately 59 inches.
Habitat
Highly aquatic; resides in lakes, rivers, ponds, marshes, and canals. Often found basking on rocks or logs near the water's edge or hiding under debris in damp areas.
Behavior & Temperament
Very defensive. When threatened, they often flatten their heads and bodies to appear larger and release a foul-smelling musk. They are primarily diurnal but may hunt nocturnally in hot weather.
Diet & Feeding
Active foragers that primarily eat fish and amphibians (frogs, toads, salamanders). They do not constrict, instead swallowing prey alive.
Reproduction
Viviparous (gives birth to live young). Litters typically range from 15 to 30 young, usually born in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the Northern Cottonmouth (Agkistrodon piscivorus). Watersnakes can be distinguished by their round pupils (vs. vertical/slit), lack of heat-sensing pits between the eye and nostril, and the presence of dark vertical lines on the labial scales.
Conservation Status
Least Concern (IUCN). Extremely common throughout its range, though often killed by humans due to confusion with venomous species.
Cultural Significance
Crucial for ecosystem balance by controlling fish and amphibian populations. They are often the subject of 'snake stories' due to their resemblance to Agkistrodon species.
Notable Features
Distinguished by the dark vertical lines on the labial (lip) scales and heavily keeled scales, giving them a rough, non-reflective appearance when dry.