May 17, 2025
Nature's immortals: Hydra, jellyfish & ancient life
Siddhartha JanaHydra’s immortal cells
Hydra are freshwater creatures made entirely of stem cells, allowing them to constantly regenerate and avoid aging—making them biologically immortal, though still vulnerable to threats.
Source: Canva
The immortal jellyfish
Turritopsis dohrnii can reverse its life cycle from adult back to polyp when injured or starved, allowing it to potentially live forever without dying of old age.
Source: Canva
Ancient glass sponges
Glass sponges, deep-sea animals similar to corals, can live over 10,000 years. One in Antarctica's Ross Sea is considered the oldest known animal on Earth.
Source: Canva
Long-living black corals
Black corals, found in deep waters like Hawaii, grow slowly as polyps replace themselves. Radiocarbon dating shows some are over 4,265 years old.
Source: Freepik
500-year-old clams
Ocean quahog clams from the North Atlantic can live over 500 years. One clam, discovered near Iceland, was found to be 507 years old by scientists.
Source: Canva
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