Nerodia fasciata (Southern Water Snake) is a species of snakes in the family colubrid snakes. They are associated with freshwater habitat. They are found in The Nearctic and The Neotropics.
Definition: The largest scale biogeographic division of the earth's surface based on the historic and evolutionary distribution patterns of plants and animals.
Definition: A habitat that is in or on a body of water containing low concentrations of dissolved salts and other total dissolved solids (<0.5 grams dissolved salts per litre).
Comment: "Large" is ambiguous. For details on "Large rivers" (e.g. the Mekong river) see http://worldwildlife.org/biomes/large-river-ecosystems This class will be replaced with a less ambiguous class.
