What is the Genus: Crotalus
Crotalus Overview
Crotalus is a genus of venomous pit vipers in the family Viperidae, known as rattlesnakes or rattlers. Currently, 32 to 45 species are recognized as being valid.
For this article, we will only be discussing the Crotalus genus that is found in the southwest. (Links to each state are at the bottom of the article to view the snake in each southwestern state.)
Related Article >> Snakes in Nevada

Beware Rattlesnakes Sign does not encourage hikers to explore off trail
Taxonomy
The generic name Crotalus is derived from the Greek word κρόταλον krótalοn, which means “rattle” or “castanet”, and refers to the rattle on the end of the tail, which makes this group (genera Crotalus and Sistrurus) so distinctive.
- Kingdom: Animalia
- Phylum: Chordata
- Class: Reptilia
- Order: Squamata
- Suborder: Serpentes
- Family: Viperidae
- Subfamily: Crotalinae
- Genus: Crotalus
Subspecies of Crotalus
Subspecies of Crotalus
Size and Body Description
In general, adult males are slightly larger than females.
Compared to most snakes, they are heavy-bodied and most forms in the Southwest are easily recognized by the characteristic rattle on the end of their tails
Length
Members of the genus Crotalus range in size from only 20″ – 28″ (C. intermedius, C. pricei), to over 59″ (eastern and western diamondback rattlesnakes).
Reproduction
The genus Crotalus is ovoviviparous, giving birth to live young.
Range
The genus Crotalus is found in the Americas from southern Canada to central Argentina.

Where Found
They live in a variety of habitats, including forests, grasslands, scrub brush, swamps, and deserts, and they are also capable swimmers.
How Long do Crotalus Live
A rattlesnake’s typical lifespan is 10 to 25 years.
Crotalus Diet
Rattlesnakes eat their food whole and because of this and with rattlesnakes having a very slow metabolism, adult rattlesnakes eat at least once in two weeks and their young eat once a week.
Snakes do not have the right kind of teeth to chew their food so they must eat their food whole. The jaws of snakes are not fused to the skull, so the lower jaw can separate from the upper jaw. This allows their mouths to open wider than their own bodies in order to swallow their prey whole.
They favor small rodents and lizards. Smaller species feed mainly on lizards, while larger species start by feeding on lizards as juveniles and then switch to preying mainly on mammals as adults.
Water Sources
Herpetologists suspect that many desert-dwelling reptiles—including rattlesnakes—collect and drink rainwater that pools on their dorsal surfaces.
Related Content
- Snakes in Arizona
- Snakes in California
- Snakes in Nevada
- Snakes in Utah
- Reptiles
- Classification of Reptiles