Fangtooth

About the Fangtooth

If someone tells you that you’re getting “long in the tooth,” it’s a euphemism for getting old. But the fangtooth is just born that way. Though fairly small in size, this critter boasts the greatest teeth-to-body-size ratio of any fish in the ocean. For the sake of polite conversation, we won’t dwell on the mucous-filled cavities lining its face. Fish have feelings, too.

Adult fangtooth fish dwell primarily in the twilight zone, but juveniles hang out near the surface, where they feed on zooplankton until they develop their signature chompers. Despite an adults’ fearsome appearance, however, it’s actually somewhat defenseless: its small, milky-blue eyes aren’t very powerful, so it relies on its lateral line—a sensitive organ that runs down the side of its body—to pick up movement and temperature changes. In order to avoid predators, the fish has also evolved special “ultra-black” skin with concentrated pigment that’s able to absorb 99.5% of light, effectively letting it hide in plain sight. 

When it comes to food, the fangtooth is an opportunistic hunter, using special chemical receptors to “smell” the water around it for prey. When an unfortunate animal swims within gulping distance, those prominent fangs work like a trap, letting the fangtooth catch fish bigger than itself. Luckily, special sockets on the roof of its mouth prevent it from skewering its own brain with its swordlike teeth.

At the moment, there are only two known species of the fish: the common fangtooth, which is found in temperate waters and measures up to 16 cm; and the shorthorn fangtooth, which is about half the size and lives in tropical zones from the western Pacific to the western Atlantic.