The strange fish that changes 20 teeth a day

It spends its life breaking carapaces but its teeth are not scratched: the case of the Lingod, the Pacific fish that makes 20 teeth fall out and grow back every day

It can grow up to a meter and a half long and weigh up to 80 kilos, but above all it has very sharp teeth: it is the Pacific Lingcod, a fish that lives along all the ocean coasts from Alaska to Mexico. With its teeth it can crack the shells of crustaceans and mollusks, but in a lifetime of crab hunting nothing seems to scratch its canines, molars and premolars. Now we know why.

The discovery of zoologists

Up to 500 teeth that the Lingcod manages to extend out of the jaw, to destroy the hardest carapaces. How is it possible that not a single tooth gets damaged, nicked or falls out? It is because the Lingcod replaces 3% of them every day. That's what zoologists at the Royal Society B have discovered: the fish drops 20 teeth every day and grows as many new ones.

The researchers have captured about 20 Lingcod, and are observing them in laboratories at the University of Washington to monitor the phenomenon. The fish were placed in a tank of seawater in which there was a red dye that stained their teeth, then returned to their normal tank for ten days. At the end of this period, the Lingcod were placed in a tank with a green dye, then they were examined. The teeth that were present from the beginning of the experiment were both red and green, but there were also some teeth that were only green: this means that they were new teeth, which had never seen the red dye.

The scientists examined about 10 thousand of them, and also realized how quickly the teeth are replaced. It was a phenomenon found mostly in sharks, which are mammals, however.

The characteristics of the Pacific Lingcod

The Lingcod is, all things considered, an unremarkable fish. Twenty percent are fluorescent green or blue in color, for a reason that is still unclear. If it weren't for the fact that they change 20 teeth a day they'd be just another species, unlike some of its "colleagues".

Like other types of fish they have two rows of teeth, an anterior one that catches prey and a posterior one that crushes and mangles it. Researchers have found that most of the teeth that are replaced are in the back row. When the Lingcod loses a tooth, it regrows one of the same type and size, as happens to humans as they transition from baby teeth to adult teeth. But this isn't the first case of a fish with distinctive teeth found in the United States.