Crotalus Atrox

Crotalus atrox, the western diamondback rattlesnake, also called the western diamond-backed rattlesnake and known regionally as the adobe snake, desert diamond-back, or Texan rattlesnake, is a venomous pit viper. Adults typically reach about 120 centimeters in length, with males growing significantly larger than females, and the snake has a khaki ground color marked by 23 to 45 dark brown or umber dorsal blotches that shift from rectangular near the head to diamond shaped further back; its tail carries two to eight black bands separated by white or gray spaces, giving rise to the nickname coontail. Its venom is primarily hemotoxic, containing zinc metalloproteinases, cytotoxins, and myotoxins, with an average yield of 250 to 350 milligrams per bite and a maximum of 700 to 800 milligrams; untreated bites carry a mortality rate of 10 to 20 percent. It lives from below sea level up to about 6,500 feet in elevation, inhabiting deserts, creosote flats, mesquite grasslands, desert scrub, and pine-oak forest across flat coastal plains and steep rocky canyons. It ranges through the southwestern United States, from central Arkansas to California, and into northern Mexico, including the states of Nuevo Leon, Sonora, and Chihuahua.