It sounds like a plot from Night of the Living Dead: The creatures develop lesions, their arms start to twist and curl and eventually fall off, and then they turn into a dead, white blob. Oh, and these creatures are also known to cannibalize each other. A sign of the apocalypse? Nope, it’s just starfish wasting disease.
The outbreaks of the disease, which is known as the “sea star-associated densovirus,” cause massive die-offs of the creatures and are referred to by scientists as plagues.
Outbreaks were chronicled in 1972, 1978, and most recently in 2013, when millions of sea stars off the coast of Alaska and Canada all the way south to Mexico wasted away into gooey white clots. Scientists discovered the densovirus pathogen, which affects 19 species of sea stars and is associated with warm water temperatures, in 2014.
Healthy starfish (which are actually not fish, but echinoderms) have the ability to regenerate detached limbs — which also sounds like something from a horror movie — and some species can even grow an entire new body just from a severed arm.
There are some 2,000 species of sea stars, and although most of them have the classic five-arm star shape, there are some that have 10, 20, and as many as 40 arms. And they’re not just good at regenerating limbs, they’re also adept at reproducing. Despite the macabre effects of the plagues, scientists are hopeful that the creatures can repopulate and thrive, since a single adult can produce a hundred or more offspring.