Osedax worms have been found in oceans all over the world. They've only ever been spotted on bones, which makes some scientists think that the bone-eaters are specialized to live in odd ecosystems, such as whale falls. "Those kinds of animals are definitely uniquely adapted to the environment in which you find them, "says marine biologist River Dixon. She is a graduate student at the University of Louisiana at Lafayette.
But as recent experiments show, the bone-eaters may not be picky about what type of bones they devour(吞食). Last year, biologists spotted Osedax worms in the Gulf of Mexico for the first time. And not on whale bones. Dixon was part of a research team that made the discovery. In early 2019, her group put the dead bodies of three alligators(短吻鳄)in water about 2 kilometers deep. Over the next few months, they sent a remote-controlled vehicle a few times to spy on what were essentially "alligator falls". 51 days after the alligators were placed in the seawater, scientists revisited. "The flesh was gone", Dixon says. . "It had been reduced to just the skeleton(骨骼)." And just as at whale falls, it hosted a carpet of bone-eating Osedax worms. These worms were similar to other bone-eaters but represented a never-before observed species. That means the scientists who found them get to name it (although Dixon says they haven't settled on a name yet).
The lab where Dixon works studies food systems in the deep ocean. Algae and plants use photosynthesis(光合作用)to turn sunlight into food. Animals eat those plants and algae to survive. Then larger animals may eat those animals. But sunlight doesn't reach the deep ocean's bottom. So other pathways are essential. These pathways include whale falls and other dead bodies. The scientists wondered how alligator falls fit into a larger food web. To find out, they submerged them.
Studying alligator falls, Dixon says, could help show how life evolved(进化)in the deep sea. It's possible that the creatures found on whale falls and other falls today, Dixon says, evolved from creatures that hundreds of millions of years ago would have devoured plesiosaur (蛇颈龙) falls.