The Hydra is a fearsome mythical creature; a terrifying, multi-headed being from a fictional world. Biologists, however, understand it as a real life tentacle-wielding organism that’s immortal, one that is able to genetically alter its cells to do so.

A team of researchers from University of California, San Diego have found that instead of simply rearranging its cells to perform this act – that is highly unusual, the cells actually stretch.

The Hydra belongs to a significant group of animals (phylum) named the cnidarians, which also include jellyfish, corals and sea anemones. Hydra possess some features that readily make them noticeable from the pack. Although each share a couple of specialized prey capture cells referred to as cnidocytes. And – thanks for their regenerative abilities that are truly astounding – they could theoretically live forever. The amazing fact is, they are able to grow back from only a fragment of a tentacle.

In addition they spend most of the life motionless, and only moving when their planktonic prey drift past. And it was recently discovered – when they have got a hold on their hapless prey, they tear open their outside layer to create a ‘mouth’. When they have completed their meal, their new mouth closes up, fixed by the outstanding cellular regeneration of the Hydra.