With no brains, blood or heart, jellyfish have developed an incredible ability to survive.
TV adventurer Bear Grylls reveals the surprising facts in tonight’s episode of his wildlife show Hostile Planet.
“They start life as pinhead-sized polyps,” says Bear in the National Geographic series.
“Gorging on plankton they grow, mutate and multiply into an army of clones. No bones, no blood or even brains but perfectly suited to today’s transforming seas. Resistant to increasing temperature, decreasing oxygen, even plastic pollution. When a jellyfish swarm takes over, some ecosystems never fully recover.”
Last month Torquay, was invaded by monster barrel jellyfish, which grow to the size of dustbin lids.
Lucas Brotz, of the University of British Columbia, in Canada, said: “Jellyfish have a unique lifecycle where they can tolerate harsh conditions and then rapidly thrive when conditions are favourable.
“They can make millions of copies of themselves and clone asexually. That’s why they’ve been around for hundreds of millions of years.”
On Hostile Planet, host Bear, 44, issues stark warnings about the damage caused by climate change and pollution.
There is startling footage of the loss of coral reefs. “In three decades we’ve lost over a quarter of the world’s corals, home to around 4,000 species of fish. If warming continues we could lose the rest.
“Just a three-degree temperature rise is too much for coral.”
● Hostile Planet, National Geographic, today at 9pm.