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Photo credit:

Ricardo Ramírez Chaparro of HERP.MX
Blog can be found at

Common name

Cerralvo Rattlesnake

Scientific name

Crotalus enyo cerralvensis

Conservation Status

Federal and State Protections

Amenazada (A) - Mexico

Range Map


Countries of Occurrence


Adult size

45.7 (18in) - 76.2cm (30in)

States or Providence 

Baja California Sur


Isla Ceralvo

Species Description

This 1.5-2.5 ft long rattlesnake is only found on Isla Cerralvo, also known as Pearl Island for its history. Regardless of its size, this species feeds on lizards, mammals, and sometimes centipedes rather than switching from lizards to mammals as most rattlesnakes do. Cerralvo rattlesnakes give birth to 2-7 young, and neonates can be found between July and October.

The Cerralvo rattlesnake has the largest head-to-body ratio than all other subspecies of C. enyo. It also has a higher number of both ventral and subcaudal scales (167-181 ventral, 23-31 subcaudals) than its sister subspecies.

Fun fact: This little-known rattlesnake was last suggested to be elevated to full-species status by Beaman and Grismer, 1994. This recommendation is because of its larger head to body ratio than the other subspecies of this snake and because it is not currently exchanging genes with the mainland subspecies. Based on our research, it has not yet been categorized as its own species.

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