The zebra fish's ability to heal its spinal cord after injury could hold the key to helping paralysed humans walk again.
Scientists have discovered how, after the fish's spinal cord is cut, a "bridge" forms and over eight weeks the damage is completely repaired.
It is all down to a protein called connective tissue growth factor A (CTGFA).
Humans have a version of the protein and when human CTGFA was applied to sites of spinal injury in zebra fish, it had a dramatic effect.
Why the protein does not seem to work the same magic on humans is still being investigated.
Healing is more complex in mammals, so the team at Duke University in the US now plan to study the effect of CTGFA in mice.
Professor Kenneth Poss at Duke University said: "Given the limited number of successful therapies available today for repairing lost tissues, we need to look to animals like zebra fish for new clues.
"I don't think CTGF is the complete answer, but it's a great thing to have in hand to inform new ways to think about the real challenge of trying to improve regeneration."