Hydras, simple fresh-water animals, have the ability to live forever if kept in ideal conditions, a recent study shows.

The organisms are made mostly of stem cells that have the ability to continually divide, thus constantly renewing the body.

“The differentiated cells of the tentacles and the foot are constantly being pushed off the body and replaced with new cells migrating from the body column,” Daniel Martinez, a biologist at Pomona College, said in a statement.

A photo posted by Infobae America (@infobaeamerica) on Dec 24, 2015 at 3:44am PST

Although scientists have been keeping a close eye on the centimeter-long fresh-water polyp for quite some time now in connection with the animal’s exceptional vitality, this latest research may possess the strongest evidence yet of its potential immortality.

A paper co-authored by Martinez titled ‘Constant mortality and fertility over age in Hydra’ proves that if provided with ideal conditions, the hydra could live without showing any sign of ageing or losing fertility - something that was thought impossible for a multicellular species.

The latest research observed 2,256 hydras, recreating a little oasis for them, giving them fresh water three times a week and feeding them fresh brine shrimp.

“I do believe that an individual hydra can live forever under the right circumstances,” says Martínez. “The chances of that happening are low because hydra are exposed to the normal dangers of the wild - predation, contamination, diseases. I started my original experiment wanting to prove that hydra could not have escaped ageing. My own data has proven me wrong - twice.”

It was Martinez’s 1998 article in Experimental Gerontology, which he published after four years of research, that sparked international interest in the hydra’s possible immortality.

“Before the study, models predicted that ageing was unavoidable for animals. My results questioned the validity of those models.” Martinez said.