Nerodia is a genus of nonvenomous colubrid snakes commonly referred to as water snakes due to their aquatic behavior. The genus includes nine species, all native to North America. Description Nerodia species vary greatly, but all are relatively heavy-bodied snakes, sometimes growing to 1.2 m (4 feet) or longer in total length. They have flattened heads, with small eyes that have round pupils, and keeled dorsal scales. Species like N. fasciata display distinct banding, whereas other species, like N. erythrogaster, have blotching, and those like N. rhombifer have diamond-shaped patterning. Most species are brown or olive green, or some combination thereof with markings being brown, or black. Yellow or cream-colored accenting is common. Behavior Water snakes, as their name implies, are largely aquatic. They spend the vast majority of their time in or very near permanent sources of water. Often, they can be found basking on tree branches that overhang slow-moving streams or ponds. Diet Their primary diet is fish and amphibians, and they are quite adept at catching both in their aquatic environment. They will also consume small reptiles and rodents that live near water. Defense While their initial instinct is to flee when disturbed, water snakes readily defend themselves if they are unable to escape. They do not often hesitate to strike or bite if handled, and often expel a foul-smelling musk from their cloacae. Reproduction Nerodia species are viviparous, breeding in the spring and giving birth in the late summer or early fall. They are capable of having 90 or more young, but broods generally are much smaller. Neonates are around in length. Species and subspecies These species and subspecies are recognized as valid: Nerodia clarkii (Baird & Girard, 1853) – salt marsh snake N. c. clarkii (Baird & Girard, 1853) N. c. compressicauda (Kennicott, 1860) N. c. taeniata (Cope, 1859) Nerodia cyclopion (A.M.C. Duméril, Bibron & A.H.A. Duméril, 1854) – green water snake Nerodia erythrogaster (Forster, 1771) – plainbelly water snake N. e. alta (Conant, 1963) N. e. bogerti (Conant, 1953) N. e. erythrogaster (Forster, 1771) N. e. flavigaster (Conant, 1949) N. e. neglecta (Conant, 1949) – copperbelly water snake or copperbelly N. e. transversa (Hallowell, 1852) – blotched water snake [[File:Nerodia erythrogaster transversa.jpg|thumb|N. e. transversa]] Nerodia fasciata (Linnaeus, 1766) – banded water snake N. f. confluens (Blanchard, 1923) N. f.fasciata (Linnaeus, 1766) N. f. pictiventris (Cope, 1895) Nerodia floridana - Florida green watersnake Nerodia harteri