Everyone likely knows the story of Jonah and the whale, a tall tale even for the Old Testament: no human will make it out of a whale alive. But while humans make for a relatively frail species, many critters possess a bit more moxie than mankind, including a number of animals can survive being eaten alive. Some of these survive by regenerating missing parts of their bodies, and others just pass through the entire predator animal unscathed. These animals eaten alive might be emotionally scarred for life perhaps, but at least they can live another day.
Predators-prey relationships existed practically since life emerged on Earth, so it makes sense at some point certain species would evolve to survive the process. While never fun for these species to be eaten alive, this survival adaption often has researchers wondering how humans might use it for their own medical research. It's true that there are many amazing and incredibly hardy animal species out there, but when it comes to never giving up, these animals may be the best. After all, would you not despair if you were in the belly of a whale?
The Rough Skinned Newt Won't Be Any Frog's Dinner
Some animals on this list survive by taking the plunge all the way through an animal's digestive tract, then popping out on the other side as if they walked through a field of flowers. However, this is not the case with the rough skinned newt. This newt looks like easy prey, but any animal who eats it is in for an unfortunate surprise. Frogs often swallow them for dinner, and once inside, the newt quickly blows that popsicle stand. Their skins contain a toxin which they secrete when a predator consumes them. In the case of many frogs, they lack any resistance to this toxin, and it kills them from the inside out. Once the frog dies or is at least helpless, the newt just climbs back out through the mouth and continues on its merry way.
Fun fact: this defense mechanism actually helps curb the population of an invasive bullfrog species. The bullfrog, which evolved in an environment without the newt, never gained the proper resistance to its toxins.
Several parasites can survive being eaten, but these creatures primarily live in the gut in the first place so they hardly count for this list. However, the nematode is a little different.
These little worms live in a variety of environments, including salt water, fresh water, and even soil. In addition to natural environments, the nematode can also survive inside the bodies of animals. They survive off of bacteria in the guts of slugs and other creatures, and even stomach acid can fail to kill them. Though generally not eaten on purpose, they can be ingested out of water and soil that is consumed.
Unfortunately, this creature can also kill animals that eat it, and does so with surprising regularity. In humans, they cause diseases, and in some animals, they destroy them from the inside out. Hundreds of thousands of human deaths have been linked to these little invaders.
Sea cucumbers are curious creatures in the first place. Squishy all over, they often get eaten by animals and people as delicacies. It is fortunate, then, that sea cucumbers are one of the best regenerators in the known world. Though they heal wounds the same way most other organisms do on a molecular level, sea cucumbers can direct their healing process towards regenerating entire organs. But it doesn't stop there. If you were to take a sea cucumber, and cut it into several pieces, each piece would actually be able to regrow a whole new sea cucumber! In this way, a sea cucumber acts as a tasty treat for other sea creatures without actually losing its life.
As you might guess, this led to scientists heavily researching how they regenerate to see if humans might one day utilize this ability in modern medicine.
Perhaps one of the cutest animals on this list, the axolotl, holds no qualms about becoming another animal's lunch. This ancient creature likely survived for so long because of its remarkable regenerative abilities. There won't be any scarring from regenerated areas to show that the animal was ever harmed, and while similar species can regenerate parts of themselves, no salamander does it better than the axolotl. If attacked, the axolotl can safely lose large parts of its body, even vital organs, and still keep going. Even more mind blowing, the axolotl accepts organs from other organisms transplanted into its body.
This is another species that scientists are frantically researching for potential medical advances, especially considering their status as critically endangered organisms!