A kitefin shark is the largest known bioluminescent vertebrate, according to a new study. The shark lives in the dimly lit "twilight zone" of the ocean, and may glow to camouflage itself as it hunts.

Sharks are known to stalk and sniff out prey before they attack. But all this newly discovered shark species has to do is glow in the dark, and the prey comes to them. The 5 1/2-inch American ...