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Today on Animal Fact Files we’re discussing fangtooth fish. Fangtooths get their common name for their fang-like teeth. Adult fangtooths have teeth so large they're actually considered the largest teeth relative to body size in all living marine fish! Though they look ferocious, they can't harm a human. Adult fangtooths live deep in the ocean's depths. 

Fangtooth fish are also known as ogrefish. Their head makes up approximately one third of their body length! In size, fangtooths max out at just over half a foot (15cm) in length. What's more, the adults look nothing like the juveniles. In fact, juvenile ogrefish were believed to be a completely different species until the mid 20th century!

There are currently two described fangtooth species. They can be told apart by their young. Common fangtooth juveniles have long spines protruding from their head while shorthorn fangtooth juveniles do not - can you see why they got those common names? Aside from the horns, which aren't present in adults, juvenile fangtooths have larger eyes and smaller teeth than their adult counterparts. Like vampire fish, adult fangtooth teeth are so large, the fangs on the lower jaw have special holes in their head alongside their brains which their long teeth slide into! The teeth in the upper jaw remain outside like an overbite when the mouth is closed.

Those teeth help a fangtooth catch prey. These fish are carnivorous. Young fangtooths eat crustaceans like copepods and shrimp, but the adults munch on other fish who can reach upwards of ⅓ their size! That's a mouthful of food they swallow in one big bite, so adult fangtooths have a special way of breathing while they eat. They'll open the flap that protects their gills and use their fins to push water over their gills while they eat! This is known as reverse direct ventilation and it's uncommon in fish, though we've discussed others that do it, too! Even with a full mouth a fangtooth doesn't have to worry about choking! 

Young fangtooths live near the water's surface with larvae living six feet (1.8m) below the surface. Adults, however, live in the depths of the ocean. They're common from 1,600 to 6,500 feet (500-2,000m) below the waves but are known to dive deeper than three miles (4,800m) There's no light where they live, so they depend on a prominent lateral line that detects movement in the surrounding water. Still, this doesn't keep them safe from predators like tuna and marlin. Fangtooths are covered in prickly scales and spines which may deter predators and they are dark in color which helps them blend in with the inky black below.

Fangtooths live in tropical to subarctic seas around the world. It's unknown how long fangtooth fish live or how they reproduce. Females are generally described as larger than males, and it's possible the males use their strong teeth to grab hold of the female and become a sperm producing parasite much like the tiny males in deep sea anglerfish! These fish live alone or can even be found swimming in small groups.

For more facts on fangtooths, check out the links below. Give a thumbs up if you learned something new today. Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! And thank you for watching Animal Fact Files!