PASADENA, Calif., June 16 (UPI) -- Most animals can self-repair injuries to some degree, but few do it better or more efficiently than the jellyfish-like hydra, a genus of soft-bodied organisms found mostly in freshwater.
Hydra are often the subject of studies on tissue regeneration, but researchers at Caltech wanted to focus on another creature, the moon jellyfish (Aurelia aurita).
To study the jellyfish's self-repair abilities, researchers amputated various numbers of arms from (anesthetized) juvenile specimens.
Researchers found the jellyfish were quick to heal their wounds, but didn't regrow tissue as expected. Instead, the jellies simply redistributed their remaining tissue to achieve symmetry. Regardless of how many limbs were lost, the jellies were able to symmetrically reorganize their bodies.
"This is a different strategy of self-repair," study author Lea Goentoro, an assistant professor of biology at Caltech, explained in a press release. "Some animals just heal their wounds, other animals regenerate what is lost, but the moon jelly ephyrae don't regenerate their lost limbs. They heal the wound, but then they reorganize to regain symmetry."
Goentoro and his colleagues determined the jellyfish weren't actually killing or creating new tissue cells, but simply working with what they had. The jellies were able to shift their tissue by manipulating their muscles. When researchers put muscle relaxants in the water, the jellyfish's symmetrical reorganization abilities were impaired.
The new research was recently published in the journal PNAS.