Starfish Longevity: Cloning Lengthens Life

For starfish, avoiding sex provides greater health and a longer life.

That is, starfish that reproduce through cloning age less than those that propogate through sexual reproduction, researchers with the University of Gothenburg have found. Their findings were recently published in Heredity.

Researchers investigated the lengths of telomeres -- a compound structure at the end of a chromosome -- and population genetics of a starfish, Coscinasterias tenuispina. Telomeres affect an individual's health and lifespan.

In the study, both Mediterranean and Atlantic populations of starfish were analyzed.

 "Our results from the genetic markers show that the starfish are more inclined to clone themselves in the Mediterranean," says Helen Nilsson Sköld from the University of Gothenburg's Sven Lovén Centre for Marine Sciences in Kristineberg. "In actual fact, there only appears to be a single clone off the Spanish Costa Brava. In the Atlantic, however, sexual reproduction is more common."

The Gothenburg scientists found a clear positive link between long telomeres and the level of clonality. Newly formed tissue also had longer telomeres, Sköld said. 

The idea is that newly rejuvenated telomeres in connection with the formation of new tissue during cloning was possibly an explanation behind the very good health and long telomeres of clones, the Gothenburg researchers said.

The idea behind the study, that clones avoid aging by regulating telomeres, has been previously studied by other researchers regarding flatworms.

 "The strengths of our study are that we have confirmed these results in a completely different animal group, and that our data comes from wild populations," Sköld concludes.