A mysterious plague has manifested in the world's starfish population, quickly spreading to several regions in which starfish (also called "sea stars") are found. Starfish afflicted with the disease tear themselves to pieces, the arms crawling in opposite directions until the animals are literally torn to pieces. Unlike healthy starfish, the affected animals are not able to regenerate after they are torn apart.

The disease is largely a mystery. Researchers who are studying it are asking beach-walkers to photograph any starfish they see to tweet photos of it with the #sickstarfish tag. Starfish are important marine predators; a serious depletion of their numbers will have far-reaching consequences for marine ecosystems.

BEN MINER: The experiments are infectiousness experiments, where we take individuals that have signs of the syndrome and we put them in tanks with individuals that don't have signs. KATIE CAMPBELL: Then they closely watch the progress of the disease. First, the stars twist their arms into knots, and sometimes lesions form on their skin. BEN MINER: One of them was very sick, and the other two individuals started ripping themselves apart. The arms just crawl away from the particular body. KATIE CAMPBELL: You heard that right. The arms crawl in opposite directions, until they tear away from the body and their insides spill out. And unlike most starfish, the arms don't regenerate. Stars that came in with symptoms died within 24 hours.

Mysterious epidemic devastates starfish population off the Pacific Coast [PBS]

(via IO9)