Natures wonders: bombardier escape mechanism (Introduction)

by David Turell , Thursday, February 08, 2018, 00:08 (2270 days ago) @ David Turell

Bombardier beetles famously eject a very hot toxin and use it to escape after being swallowed by toads:

https://www.newscientist.com/article/2160429-beetles-escape-alive-after-almost-2-hours-...

"Imagine spending almost two hours wallowing in the stomach juices of a toad. Bombardier beetles do just that, but they have found a way to escape alive.

"A swallowed bombardier beetle squirts so much hot, toxic fluid into the toad’s stomach that the animal is sick, ejecting the beetle to freedom.

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"Bombardier beetles famously produce explosive jets of hot, corrosive and toxic chemicals from their rear ends when threatened. Reaching temperatures of 100°C, the jets make loud popping noises and generate clouds of smoke and steam.

"To find out if this is how the beetles escape, Sugiura and Sato fed single bombardier beetles to toads. They provoked half the beetles to jettison their toxic loads beforehand, depriving them of this means of defense.

"Only 3 out of 37 disarmed beetles survived, whereas 16 out of 37 fully-armed beetles escaped. “We showed that the bombardier beetle ejects toxic chemicals inside the toad, forcing it to vomit,” says Sugiura.

"Bigger beetles survived best, probably because they ejected more toxic fluid and were harder to digest. Likewise, smaller toads allowed more beetles to escape.

"In another experiment, the researchers found bombardier beetles are more likely to survive after 20 minutes in a toad stomach than 14 other beetle species. This suggests they have evolved a tolerance for toad digestive juices.

"Several other prey species are known to escape digestion. They include snails eaten by birds, mussels eaten by sea anemones and nematode worms eaten by slugs. Toxins from the rough-skinned newt rapidly kill frogs that eat it, allowing the newts to crawl back out again."

Comment: Not surprising since the bombardier has the mechanism of defense. The real issue is how did the bombardier evolve the hot toxin and not have it harm itself. Must be done with defenses for its own tissues in space