With a name that matches the multi-headed monster of Greek mythology, hydra are a form of freshwater polyp that resemble a thin tube-like organism with tentacles protruding from one end.
What makes them particularly interesting is the fact that they do not appear to deteriorate with age meaning that there is no practical limit to the amount of time that they can live for.
Biologist Daniel Martinez, who originally set out many years ago to prove that these remarkable creatures must still be subject to the ageing process, has ended up having to admit defeat.
“I do believe that an individual hydra can live forever under the right circumstances,” he said.
The key to their unlimited longevity seems to be the fact that their bodies are mostly comprised of stem cells which are capable of continuous division and differentiation. In humans we lose these cells within the first few days of embryonic development whereas the hydra keep them indefinitely.
“I’m hoping this work helps spark another scientist to take a deeper look at immortality,” said Martinez. “Perhaps in some other organism that helps bring more light to the mysteries of aging.”
