Not scared yet? Well, one of the invisible shark species is nicknamed the phantom hunter of the fjords.
The real name of the phantom hunter is Etmopterus spinax, or velvet belly lantern shark, which lives in the deep waters of the northeastern Atlantic Ocean. According to a study published in the Journal of Experimental Marine Biology and Ecology, the shark becomes invisible by regulating the photophores underneath its body. This makes their belly glow matching the light of the sun above them, as filtered by the sea. As a result, preys or predators looking from under them are not able to see them.
I have no idea what photophores are, but if they're anything like photophives you call them to secure your seat while you go to the bathroom. Now if you'll excu-- PHOTOPHIFTEENS! (I like to sit down to pee)
Thanks to Justin, who once punched a shark in the nose and called it a tuna. Ooooh -- that's cold!