Earth Notes: Mohave Rattlesnake Venom

Jul 3, 2019

Mohave rattlesnakes are armed with a powerful weapon—venom that can immobilize or kill their prey. People have believed the Mohave’s venom held a neurotoxin, a cocktail of enzymes and peptides that paralyze the nervous system—making a bite from this snake especially deadly.

Mohave rattlesnake
Credit Brian Wooldridge, USFWS

Human snakebite records back to the 1920s have supported this belief. But when some unfortunate patients showed different symptoms, including tissue damage, disorientation, and blood clotting difficulty, it was discovered that some snakes have a hemorrhagic venom that destroys body tissues—essentially injecting the victim with a dose of meat tenderizer.

In 2018 researchers Jason Strickland and Christopher Parkinson from Clemson College of Science set out to learn more. They used networking and social media to recruit research students and nearly a hundred citizen scientists to catch snakes and collect venom across the Southwest and Mexico.

They found that Mohave rattlers with neurotoxins predominate across much of Arizona. But the hemotoxin is more widespread than previously thought across both Arizona and Mexico—especially between Phoenix and Tucson where snakes may have either venom type. There are even instances where both types of venom are found in the same snake—most often along the I-10 corridor between the two cities.

If bitten, you’ll be given an antivenin “cocktail” sourced from at least five different rattlesnake species across North and South America, including ones with hemorrhagic and neurotoxins. 

And that’s good news, given that Mohave rattlesnake venom varies so much from place to place!