Sometimes the best way to answer a question like "How many animals on the bottom of the ocean glow?" is to just go down there and poke some sea creatures with a robot arm. That's how researchers found out that the pitch-black seafloor in the Bahamas is alive with bioluminescence. They also found glowing currents full of plankton, a crustacean with the world's slowest vision, and creatures that vomit light when provoked.
In the middle depths of the ocean, making your own light is ordinary. Around 80 percent of fish and crustaceans that live here are bioluminescent, and the skill is also common in squid and other cephalopods. These animals may light up to lure prey, confuse predators, or attract a mate.
Species that live on the bottom of the ocean are less well studied, for the obvious reason that they're on the bottom of the ocean. So researchers led ...
