Copperheads have chestnut or reddish-brown crossbands on a lighter-colored body. These snakes are found in rocky areas and wooded bottomlands and are rare in dry areas. In the spring, they can be found along streams and rivers, as well as in weed-covered vacant lots. There are three subspecies of Copperheads in Texas; Southern copperhead (A.c. contortrix), 20-30 inches long and found in the eastern one-third of the state; Broad Banded copperhead (A.c. laticinctus), about two feet long, widely scattered in central and western Texas; and the Trans-Pecos copperhead (A.c. pictigaster), 20-30 inches in length and found near springs in the southern part of the Trans-Pecos.

The Latin name piscivorous means 'fish eating,' indicating its dietary characteristics. Also known as 'water moccasins', only one recognized subspecies is found in Texas: Western cottonmouth (A.p. leucostoma). Cottonmouths can be dark brown, olive brown, olive green, or almost solid black. They are marked with wide, dark bands, which are more distinct in some individuals than in others. Juvenile snakes are more brilliantly marked. The cottonmouth gets its name from the white tissue inside its mouth, which it displays when threatened. This heavy-bodied snake, which averages about 3-1/2 feet in length, is found over the eastern half of the state in swamps and sluggish waterways, coastal marshes, rivers, ponds, and streams.

There are two groups of rattlesnakes. The more primitive forms belong to the genus Sistrurus. Texas has two:

• Western massasauga (Sistrurus catenatus tergeminus): Light gray, with brown oval blotches along the middle of the back and smaller blotches along each side. They are two feet in length and found through the middle of the state in grasslands, marshy, and swampy areas.

• Desert massasauga (S.c. edwardsii): Lighter in color than the western massasauga, smaller and more slender. Found in the Trans-Pecos, western Panhandle, and the lower Rio Grande Valley.