Giant sea spiders sit and wait for prey to knock themselves out

Giant sea spiders can only move at glacial speeds, but they are still deadly predators that can catch prey much faster than them.

Sea spiders are found throughout the ocean. Despite their name, they are not true spiders but belong to a related group.

Many sea spiders are “stealth vampires”, says Amy Moran at the University of Hawai‘i at Mānoa. They creep around the seabed in search of immobile prey, like anemones or corals. Once a sea spider stumbles on a victim, it punches small holes in…