This Fish Loses 20 Teeth Each Day, Then Grows Them All Back

One fish, two fish. Green fish, blue fish. Outer teeth, inner teeth. These fish grow a lot of teeth.

If there is one place you don’t want to stick your finger, it’s the mouth of a Pacific lingcod. These fearsome fish, which can grow up to five feet in length and weigh 80 pounds, have around 500 needlelike teeth sticking out of jaws that are strong enough to crush crustaceans.

Having so many sharp chompers allows these ambush predators to subdue everything from slippery squid to heavily armored crabs. How lingcod maintain the sharpness of their terrifying teeth has long been a mystery. But a study, published in October in the Proceedings of the Royal Society B, claims that Pacific lingcod keep their teeth sharp and shiny by replacing about three percent of them every day. For a lingcod, that’s a whopping 20 teeth replaced daily. If you replaced your teeth at the same rate, you might lose and gain a new tooth every day — ouch!

Much of what scientists know about tooth replacement in fishes comes from sharks, which have multiple rows of teeth inside their jaws that are constantly being replenished, and other fish with unusual teeth. But shark teeth differ in significant ways from those found in the majority of fishes, which is why the lingcod findings could help scientists better understand the phenomenon of tooth replacement in fishes.