Some animals survive and even become more resistant when they taste poison. But these snakes may hold the key to this liver superpower.
Collected in the Colombian Amazon, ten snakes had not eaten in captivity for several days when they were presented with an extremely unappealing prey: three-striped poison dart frogs.
Eat or die. This was the dilemma they faced. Four boldly advanced to the attack.
But, before swallowing their meals, these snakes dragged the frogs along the ground — behavior similar to that of some birds, which rub toxins from their prey, observed biologist Valeria Ramírez Castañeda, from the University of California and colleagues who carried out the experiment.
Three of the four snakes survived — suggesting that their bodies were capable of dealing with the remaining toxins. The researchers detailed the experiment in a paper published this summer.
Scientists are beginning to unravel these creative antitoxic defenses and hope to identify better treatments for poisonings in humans. “It only takes milligrams of a single compound to alter all interactions in an ecosystem,” says biologist Rebecca Tarvin.
Other animals harbor toxin-producing bacteria — this is the case of puffer fish, whose meat contains tetrodotoxin and can be lethal if consumed.
And many get their toxins through food — like poison dart frogs that devour toxic insects and mites. These frogs include the three-striped dart frogs that were given to land snakes.
In the case of king snakes, the liver seems to be the key. Cell culture experiments suggest that something in snake livers protects against frog toxins.
A toxin produced in an Ontario milkweed plant helped shape the biology of a bird that forages thousands of kilometers away. “It’s simply incredible,” says the researcher. “The journey taken by this small molecule and the influence it has on evolution”.
