Mississippi Green Water Snake



Scientific name: Nerodia cyclopion (DUMÉRIL, BIBRON & DUMÉRIL 1854)
* Currently accepted name

* scientific names used through time

  • Tropidonotus cyclopion – DUMÉRIL, BIBRON & DUMÉRIL 1854
  • Tropidonotus cyclopium [sic] – BOULENGER 1893
  • Natrix cyclopion – BURT 1935
  • Natrix cyclopion cyclopion – CONANT 1958
  • Nerodia cyclopion – CONANT & COLLINS 1991

Adults average from 30-45 inches (76-114 cm), record 50 inches (127 cm). Adults are thick bodied and may be greenish or brownish, with no real distinctive markings other than dark speckling. The belly is patterned with light half moons on a darker background. The head is large, with a scale between the eye and the scales on the upper lip. The scales are keeled and there are 27-29 dorsal scale rows at midbody. The pupil is round. Juveniles are distinctly speckled and crossbanded.


A. Top of the head
B. Underside of the head (chin and throat)
C. Elongated scales below the tail (subcaudal scales) are typically divided
D. Front (face view) of the head
E. Side of the head
F. Keeled scales

Range: In Florida, it is found only in the western panhandle. Outside of Florida, it occurs along the Gulf coast from western Florida to Texas and up the Mississippi River to extreme southern Illinois.

Habitat: Commonly found in calm waters of cypress swamps, but also found in sloughs and inundated woodlands.


Comments: HARMLESS (Non-Venomous), though they will bite to defend themselves. The Mississippi Green Water Snake is mainly nocturnal, yet it is sometimes seen basking during the daytime.

It feeds primarily on fishes, frogs, tadpoles, and salamanders. It is live-bearing. Usually 15-25 live young are born in the summer.

Comparison with other species: The Florida Green Water Snake (Nerodia floridana) has an unpatterned belly. All other Water Snakes lack scales between the eyes and the scales of the upper lip.

Water Snakes are harmless, through they have a mouth full of teeth and will readily bite if they feel theatened. Because they are found around bodies of water, Water Snakes are often mistaken for the venomous Cottonmouth (Agkistrodon piscivorus). Nevertheless, Cottonmouths can easily be distinguished from Water Snakes. The Cottonmouth has a triangular shaped head and vertical pupil. If the head is viewed from above, the eyes of Cottonmouths cannot be seen while the eyes of Water Snakes are visible; Cottonmouths have elliptical pupils and Water Snakes have round pupils; and Cottonmouths have a facial pit between the nostril and the eye, while Water Snakes have none.