Lance-headed Rattlesnake(Pit Viper) - Crotalus Polystictus

 Lance-headed rattlesnake is a poisonous pit viper species of snake occurring in central Mexico. Currently, there are no recognized subspecies of this species.

Lance-headed Rattlesnake

Kingdom	Animalia
Phylum	Chordata
Subphylum	Vertebrata
Class	Reptilia
Order	Squamata
Suborder	Serpentes
Family	Viperidae
Subfamily	Crotalinae
Genus	Crotalus
Scientific Name	Crotalus polystictus

Description

The lance head rattlesnake's scientific name, Crotalus polystictus, translates from the Greek "poly" meaning many and "sticto" meaning spotted, describing the snake's general appearance. The characteristic dark spots that mark lance heads are unique to this species of rattlesnake. They are often oval or elongated toward the front of the body and more circular toward the middle of the animal. The snake's coloration ranges from tan or brown to gray and sometimes white. An orange-brown stripe also runs along this species back, most noticeably between spots. 

Lance head rattlesnakes yield a fairly large amount of venom per bite—80 to 100 milligrams—and are also equipped with long fangs, earning them a dangerous reputation. A sexually dimorphic species, males tend to have a larger head, which correlates to their preference for preying upon larger mammals. Smaller-headed females tend to seek out smaller prey. 

This species will vibrate its tail when alarmed, creating a rattling sound in an attempt to ward off potential predators. The rattling sound is created through the rapid vibration of a series of loose-fitting, interlocking scales at the base of the tail. When vibration occurs, the edges of the scales rub against one another to create the rattlesnake's characteristic sound.

Size

Small-to-medium sized rattlesnakes, most lance heads grow between 27.5 and 31.5 inches (70 to 80 centimeters), occasionally reaching lengths of 39 inches (100 centimeters). 

Native Habitat

Lance head rattlesnakes are native to Mexico, inhabiting the central portion of the Mexican plateau at elevations ranging from 4,750 to 8,500 feet (1,450 to 2,600 meters). This species is terrestrial, preferring a habitat of various types of grasslands, scrublands, pine and oak forests with rocky outcrops and even areas of old lava flows.

Food/Eating Habits

These rattlesnakes primarily prey upon amphibians and other reptiles, as well as the occasional insects or mammals. A venomous snake, they use a quick strike, penetration and injectoin of venom to subdue prey.

Reproduction and Development

Lance head rattlesnakes are viviparous. At birth, young lance head rattlesnakes range from 9 to 39 inches (230 to 985 millimeters) in length.

MORE FACTS

The Pit viper snake's rattling sound is created through the rapid vibration of a series of loose-fitting, interlocking scales at the base of the tail.

Lance head rattlesnakes yield a fairly large amount of venom per bite—about 80 to 100 milligrams.