(Trapido, 1941) – Brazos water snake Nerodia paucimaculata (Tinkle & Conant, 1961) – Concho water snake Nerodia rhombifer (Hallowell, 1852) – diamondback water snake N. r. blanchardi (Clay, 1938) N. r. rhombifer (Hallowell, 1852) N. r. werleri (Conant, 1953) Nerodia sipedon (Linnaeus, 1758) – common water snake N. s. insularum (Conant & Clay, 1937) N. s. pleuralis (Cope, 1892) N. s. sipedon (Linnaeus, 1758) N. s. williamengelsi (Conant & Lazell, 1973) Nerodia taxispilota (Holbrook, 1842) – brown water snake Distribution Nerodia species are widely spread throughout the southern and eastern half of the United States, north into Canada and south into Mexico, as well as to the island of Cuba. Many ranges overlap, and intergrading of subspecies is not unknown, but is rare. Two species of Nerodia are invasive in the southwest US. N. clarkii - around the Gulf of Mexico (Florida, Louisiana, Mississippi, Texas) and Cuba N. cyclopion - Texas, Louisiana, Arkansas, Missouri, Illinois, Mississippi, Alabama, Georgia, Florida, South Carolina, Tennessee, and Kentucky N. erythrogaster - Texas, Oklahoma, Kansas, Louisiana, Arkansas, Missouri, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Illinois, Indiana, Ohio, Michigan, Iowa, Delaware and into Mexico (Durango, Zacatecas, Coahuila, and Nuevo León) N. fasciata - Texas, Louisiana, Oklahoma, Arkansas, Mississippi, Alabama, Florida, Georgia, South Carolina, North Carolina, Missouri, and Illinois N. harteri - west-central Texas N. paucimaculata - Central Texas N. rhombifer - Texas, Oklahoma, Kansas, Louisiana, Arkansas, Missouri, Illinois, Indiana, Tennessee, Mississippi, and Alabama, as well as south into Mexico (Coahuila, Nuevo León, Tamaulipas, and Veracruz) N. sipedon - Colorado, Nebraska, Kansas, Oklahoma, Iowa, Missouri, Arkansas, Minnesota, Wisconsin, Illinois, Tennessee, Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Kentucky, West Virginia, Virginia, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire, Maine, Massachusetts, Rhode Island, Connecticut, New Jersey, Delaware, Maryland, Michigan, and north into Canada N. taxispilota - Florida, Alabama, Georgia, South Carolina, North Carolina, and Virginia In captivity Due to how widespread and extremely common they are in the wild, water snakes are often found in the exotic pet trade, throughout the United States, though they are rarely captive bred. Their relative physical plainness, compared to other available pet snake species, and their propensity to bite make them less than attractive pets to most people. They are easy to care for, though, and do quite well in captivity. Conservation concerns Some species, such as N. harteri and N. paucimaculata are only found in very