Cnidaria Frankenstein: Sea Anemone Builds Second Body From Jellyfish Tissue

Seven hundred million years is long enough for evolution to scramble most instructions beyond recognition. Not these. Scientists tucked a chip of tissue from a comb jelly embryo into a sea anemone embryo. The anemone didn't reject it. It started putting together a second body plan where there should have been only one.

Back in 1924, a biologist named Hans Spemann and his student Hilde Mangold did something similar with frogs: transplanted a nub of tissue from one embryo into another and watched the embryo begin building a second body, starting with the nervous system. It proved that a specific cluster of cells acts as the embryo's construction foreman, telling the body which way is up, which is front, where to put the brain. Spemann won the Nobel Prize. Mangold, who was 25, died in a household fire before the prize was awarded. Her name is on the paper; his is on the trophy.

Developmental biologist Stanislav Kremnyov and his team at Friedrich Schiller University Jena found the same command system in comb jellies, those ghostly, bioluminescent, vaguely unfinished-looking creatures that wash up on beaches.

Kremnyov performed the surgery himself, by hand, on embryos measuring 120 micrometres, barely wider than a human hair. The transplanted chip, 20 micrometres, had to be pressed directly into the recipient tissue; too loose and the embryo would reject it. The results ran in Nature, whose editor said the experiments must have felt like dissecting clouds.

The sea anemone didn’t incorporate the jellyfish tissue. It ran it like a program. Whatever system governs early development has not been patched since before “species” meant anything at all.

Read the full story at University of Jena, June 17, 2026

Hot Take: This reads as sea-based Frankenstein story. Put jellyfish tissue inside a sea anemone embryo and it doesn’t behave like an intrusion. It behaves like spare parts with instructions attached.