This Worm Is A Millennial

Sometime in the late 1990s, an adult ribbon worm was scooped up from the murk in the waters off the San Juan Islands, in the Pacific Northwest. He was moved to a tank along with a smattering of other invertebrates, including two vermilion bat stars and approximately 30 beige peanut worms. In the years since, the worm has been transported across the country to Virginia, where he lives now. The bat stars died after a couple of decades, and the peanut worms have largely vanished. But the ribbon worm lives on, buried in the tank's mud. Although his exact birthday is unknown, the ribbon worm is at least 26 years old, and probably around 30.

The ribbon worm—recently dubbed Baseodiscus the Eldest, or B for short—was just confirmed to be the longest-lived ribbon worm in the world. His persistence extends the previously known maximum lifespan of such worms (three years) by an order of magnitude, per a short communication in the Journal of Experimental Zoology Part A: Ecological and Integrative Physiology. (Ribbon worms have separate sexes, and although B has not been definitively tested, researchers suspect the worm is male due to what appear to be numerous testes.)

Such a superlative is certainly impressive for any worm, but the discovery is not necessarily a surprise for scientists who work with marine invertebrates. "We tend to be kind of biased towards like things with bones and things that look like us in terms of complexity in different ways," said Chloe Goodsell, a PhD student at UC Irvine and an author on the paper. "Most of the extremely long-lived organisms on Earth are invertebrates," she added, pointing to giant clams, which can reach 100 years, and tube worms, which can reach 250 years. Ribbon worms are among the longest animals on the planet—one bootlace worm found in Scotland allegedly reached 180 feet—and scientists had long ago hypothesized the creatures lived for many years.