The banded water snake or southern water snake (Nerodia fasciata) is a species of mostly aquatic, nonvenomous, colubrid snakes endemic to the Midwest and Southeastern United States. Adults of the banded water snake measure from 61.0 to 107 cm (24.0 to 42.1 in) in total length, with a record size (in the Florida subspecies) of 158.8 cm (62.5 in) in total length. In one study, the average body mass of adult banded water snakes was 464.3 g (16.38 oz). It is typically gray, greenish-gray, or brown in color, with dark crossbanding. Many specimens are so dark in color that their patterning is barely discernible. The ventrum (belly) is typically an off-white to white. They have flat heads, and are fairly heavy-bodied. Banded water snakes may also be identified by a dark stripe which extends from the eye to the angle of the jaw. If irritated, they release a foul-smelling musk to deter predators.[citation needed] This species also exhibits sexual dimorphism in which the female is generally longer and heavier than the male. Their appearance leads them to be frequently mistaken for other snakes with which they share a habitat, including the venomous cottonmouth. (Source: Wikipedia.org, CC BY-SA)