Hydras
While some will think we’re referencing the mythological creature known as the Hydra, we’re actually bringing up a real species simply given this name. That very name is interesting to use, as this aquatic inch-long organism is capable of regrowing a lost head. We’re totally serious, and scientists are somewhat baffled by the process. Yet due to the fact that they are related to jellyfish, sea anemones, and corals…it’s not as crazy. The Cnidaria group of symmetrical invertebrates is known for having specialized survival abilities that make them incredibly unique to other species in the animal kingdom.
However, the Hydra is special because it is not only quite small but it is also thought to be biologically immortal. They can regrow any part of themselves, which makes killing them nearly impossible. The question was how they did it. Scientists found that they do this through a form of asexual reproduction, where the hydra grows a polyp that is basically a duplicate of itself. Yet this came down to budding or regenerating, where a budding head formed differently than a regenerated one. Thus, the hydra uses two different genes to accomplish each one. To this day, scientists are still trying to figure out exactly how they do this and how they choose which one.