Nearly 6300 meters below the surface of the Caribbean Sea, researchers have observed a curious site: tiny creatures that look a bit like a cross between a Halloween ghost and a flailing Muppet. Paddling in the deepest depths of the Atlantic Ocean, the poker chip–size invertebrates—isopods of the species Bathyopsurus nybelini—tug along fronds of seaweed sometimes longer than themselves while swimming upside down and backward.
