Green water snake

N. cyclopion is distributed from the Florida panhandle westward to Louisiana, and northward through the Mississippi Valley into southern Illinois.^[6]

More precisely, it is found in southwestern Alabama, southeastern Arkansas, northwestern Florida, southern Illinois, southwestern Indiana, western Kentucky, Louisiana, southern Mississippi, southeastern Missouri, western Tennessee, and southeastern Texas.^[7]

The type locality is New Orleans, Louisiana.^[6][8]

N. cyclopion differs from most other species of North American water snakes by having one or more small scales under the eye, giving the appearance of a ring of small plates around the eye, a character shared with the species N. floridana.^[9]

A heavy-bodied snake, N. cyclopion is dark green, olive, or brown dorsally. Ventrally, it is yellowish on the anterior third, and the on remainder dark brown with yellow or white semicircles.^[4]

N. cyclopion averages 76–140 cm (30-55 inches) in total length (including tail).^[10]

N. cyclopion is commonly known as both the green water snake and the Mississippi green water snake, or the Mississippi green watersnake.^[11]

The former subspecies, Nerodia cyclopion floridana (Goff, 1936), also known commonly as the Florida green water snake, has been elevated to a full species known as Nerodia floridana.^[12]

N. cyclopion prefers still waters such as bayous, lakes, marshes, ponds, sluggish streams, and swamps. It is sometimes found in brackish water.^[13]

N. cyclopion preys most commonly on fish, though it also feeds on crayfish, frogs, and salamanders.^[8][13][14] It typically forages during early evening, though hot weather causes it to forage at night.^[8]

The green water snake is ovoviviparous.^[15] Mating takes place on land in April. The young are born in July or August, and are about 25 cm (10 in) long. Brood size varies from 7 to 101, depending on the size of the female. The females, which are larger than the males and have two more dorsal scale rows, may weigh over 4.1 kg (9 lb).^[7]