A recent report identified a toxin that allows venomous centipedes to kill prey of over 15 times their size.
The majority of predators hunt prey that is smaller than them. After all, attacking an animal that is larger puts the predator at a disadvantage and could end up turning out badly – even causing death if things went awry. Centipedes, however, take on prey that is much larger than they are due to a toxin that was recently a identified by a team of Chinese researchers.
Shilong Yang, an expert in venom and toxins based out of the Kunming Institute of Zoology in China, published a report on Monday in the Proceedings of the National Academy of Sciences that detailed the toxin that gives centipedes the ability to take on prey many times their size.
The toxic molecule was isolated, and named Ssm Spooky Toxin. The golden head centipede has the scientific name Scolopendra subspinipes mutilans, which explains the Ssm part of the name. The centipedes’ toxin functions by blocking the movement of potassium into and out of mammal cells. Cells that are functioning normally need the flow of potassium ions in order to control muscle contractions, and stopping this transfer causes drastic consequences for the prey. By doing so, centipedes are able to stop their prey’s breathing and kill mammals that are far larger than themselves such as mice.
“Because potassium channels exist throughout the body, ‘centipedes venom has evolved to simultaneously disrupt cardiovascular, respiratory, muscular and nervous systems…This molecular strategy has not been found in other venomous animals,” said Yang, according to the Washington Post. The study authors are not entirely sure as to how the centipedes kill with the toxin, but the current hypothesis is that the toxin stops blood flow to the heart, which leads to heart failure followed by death.
A Potential Remedy
Human deaths from centipedes are incredibly rare. The WP reports that as of 2006, the Emergency Medicine Journal only reported three cases in which people had died of centipede venom. Despite the relatively low risks to humans, scientists are still looking into a way to address centipedes’ venom and may have found a solution that neutralizes the toxin.
The research carried out by Yang and his team suggests that a drug known as retigabine might neutralize the centipedes toxin. Retigabine is intended to treat epilepsy, but it opens the potassium channels that the venom blocks. However, back in 2017 the pharmaceutical company that manufactures the drug – GlaxoSmithKline – announced that they were going to soon discontinue the drug due a low demand. While a commercial application of Retigabine specifically for the toxin from centipedes is probably very unlikely, the fact that this study was able to both identify the mechanism by which centipedes can attack larger prey and how to combat the toxin is promising.
As mentioned above, centipedes are very unlikely to kill humans. However, the venom from a centipede is still very unpleasant. On par with a bad bee or wasp sting, these small creatures can cause some big pain. The problem is especially severe in Hawaii, where the reports say that Between 2007 and 2011, for emergency visits in the state classified as having natural causes, centipedes were responsible for 1 in 10 cases. Understanding the centipedes’ mechanism of attack is another step towards coming up with better solutions to address bites in humans while adding to our academic knowledge regarding these species.