Diamondback Water Snake
Nerodia rhombifer • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia rhombifer
Central United States and Mexico, specifically from Indiana and Illinois south to the Gulf of Mexico, and west through Texas and Oklahoma into Northern Mexico.
Look up Diamondback Water Snake in the Snake Encyclopedia →Venomous Status
Non-venomous (Aglyphous - lacks specialized venom-injecting fangs)
Danger Level
Low Risk. Though non-venomous, they are famously defensive and will bite repeatedly if cornered or handled. Their saliva contains anticoagulants that can cause profuse bleeding, and bites may lead to secondary infection.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia rhombifer
Conservation
IUCN Status: Least Concern. Populations are stable, though they face threats from habitat destruction and being mistreated due to confusion with venomous cottonmouths.
Physical Description
Robust body with keeled scales. Coloration is olive, brown, or yellowish with a distinctive dark chain-like pattern of linked diamonds along the back. The head is noticeably wider than the neck, and the eyes have round pupils. The belly is usually yellow or cream with dark crescent-shaped spots.
Size & Dimensions
The specimen appears to be an adult of average size. Adult range is typically 30-48 inches (76-122 cm), though record lengths can exceed 60 inches (150 cm).
Habitat
Semi-aquatic. Found in slow-moving bodies of water such as rivers, oxbow lakes, marshes, swamps, and ponds. They prefer environments with overhanging vegetation and logs for basking.
Behavior & Temperament
Known for a highly defensive temperament. When threatened, they flatten their heads and bodies to appear larger and will strike readily. Primarily diurnal during spring and autumn, but becomes nocturnal during hot summer months.
Diet & Feeding
Specialize in fish and amphibians. They are active foragers that hunt along the water's edge or underwater, often using their sharp teeth to grip slippery prey before swallowing it alive.
Reproduction
Viviparous (gives birth to live young). Breeding occurs in spring, with litters ranging from 13 to 62 neonates born in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Frequently confused with the venomous Cottonmouth (Agkistrodon piscivorus). Distinguishable by the round pupils (vs. vertical slit in cottonmouths), lack of heat-sensing pits, and the chain-like pattern rather than the cottonmouth's pixelated crossbands.
Conservation Status
IUCN Status: Least Concern. Populations are stable, though they face threats from habitat destruction and being mistreated due to confusion with venomous cottonmouths.
Cultural Significance
Often unfairly persecuted due to their aggressive defensive display and resemblance to venomous snakes. They play a crucial ecological role in controlling fish and amphibian populations in wetlands.
Notable Features
Features a unique 'diamond' or chain-link pattern. In the provided image, the specimen is exhibiting a defensive posture with an open mouth, a common intimidation tactic of the genus Nerodia.