You See a Venomous Black Widow. These Lizards See a Snack.

They can be found in the woodshed, crawl space and closet. They have fangs that pierce an unwary thumb and their glossy black bodies are marked with a rubies. Black widow spiders are not aggressive, but their venom makes bites extremely painful to humans and can be fatal to small animals.

In California and other Western states, the alligator lizard can be found eating widows like black popcorn.

Chris Feldman was a graduate student at the University of Nevada, Reno when he read about lizards snacking on black widows. The lizards are most likely bitten when they subdue their prey. Was they somehow protected?

The paper was published in the Royal Society Open Science. The results show that alligator lizards have evolved a remarkable ability to ignore widow venom over time.

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In the warm places of the American West, lizards are close to widows. Black widows are known to eat small lizards. He, Vicki Thill, a graduate student, and their partners brought alligator lizards and Western fence lizards to the lab to see if different species have evolved protection. They injected the lizards with black widow venom and had them run a small track to see if the venom affected their speed.

The venom was having an effect and the lizard slowed down. Alligator lizards and fence lizards showed no change despite receiving enough venom to kill five mice.

Mike Teglas is a professor at Reno and an author of the paper. We were really happy.

The researchers looked at the muscles of the lizards. Black widow venom in mammals causes damage around the bite. Fence lizards and side-blotched lizards had injuries. The muscle in alligator lizards was not damaged. The venom was not injected.

Alligator lizards have evolved a fast way to protect themselves from widows.

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"My guess is that the alligator lizards have something that circulates in their blood that works right away, meaning that some compound could be whisking away the venom before it does any damage."

He points out that California kingsnakes have evolved a defense.

He said that they have giant proteins in their blood that make them useless.

Experiments with other lizard species suggest that the alligator lizard is more vulnerable to venom from black widows than other lizards.

It will be easier to see what the alligator lizard has than it will be to discover how it achieved this feat. Dr. Feldman wonders if more studies of how many spiders lizards eat in the wild can reveal the origin of the trait.

He was inspired to study the alligator lizard's appetites after reading a 1937 letter from a herpetologist. The scientist suggested that alligator lizards could be used to control black widows in Southern California.

At the time, it wasn't understood that the toads are venomous and destructive. They helped control insects in the 20th century.

California was able to avoid that particular problem. The alligator lizards and their prey are still alive and well.