Most people bitten by venomous snakes in the United States survive because of the effectiveness of antivenom and the fact that medical help is usually readily available. However, it’s important to know the composition of venoms from snakes throughout the country because the effects of their toxins can vary widely. For example, knowing which snakes possess potent toxins that affect the nervous system or those that contain tissue digesting enzymes can help inform snake bite treatment as well as make anti-venom production more effective.
Understanding venom variation can also tell scientists a lot about the history and ecology of a particular snake species. To answer these kinds of questions we need to have a good understanding of what types of animals are typically prey items for a certain species or population. For example, sea snakes primarily feed on fish which is reflected in the toxins present in their venoms that are very effective at killing fish. Rattlesnakes in general tend to feed on small mammals like mice, but will eat whatever they can get, leading to venoms with many different kinds of toxins that can kill prey in a variety of different ways.
The Prairie rattlesnake is not only common in Colorado, it’s range spreads from southern Canada to northern Mexico. Though it has such a large range, we still don’t understand how or why its venom varies. Because of this our lab is interested in studying geographic variation in venom composition since this species lives in many different environments with many different prey items. By separating and purifying the main toxins that make up venoms from snakes in geographically distinct areas, we now know that this species varies in levels of medically significant toxins throughout its range. We see snakes in certain areas with higher amounts of tissue digesting enzymes, while snakes in other areas primarily have potent toxins that affect the nervous system. Knowing these differences can help medical professionals give better medical care to people bitten in different areas. Our study will be ongoing for the next few years, and we hope that our research can answer questions about snake ecology as well as help with snake bite treatment.
PhD student, Venom Analysis Lab
Curator, UNC Museum of Natural History
University of Northern Colorado