Shark-tooth saw slices salmon to test for the toughest teeth

Like something out of a 1990s era cartoon show, reserachers have constructed a shark-saw, and are ready to fight crime and save the world! Or to study how quickly shark teeth dull relative to their sharpness and usage. One or the other.

The important thing is that people at Harvard University rigged up a jigsaw to use “blades” lined with shark teeth from varying species. The saw as then secured to a fulcrum, powered on and dropped onto a hunk of raw salmon. The moving tooth-blade was meant to simulate the attack of a living shark, which usually attacks a target with an open mouth, biting and shaking it laterally to tear off flesh that is then swallowed. Sharks don’t really chew their food, so the saw didn’t have to imitate the more complex motions usually associated with molars.

Razor-sharp versus reliable

After multiple rounds of testing, the basic trend that emerged was that sharks may trade sharpness for durability. Tiger, silky and sandbar sharks all have particularly sharp teeth for slicing their food, and may even take on the tough carapace of a sea turtle. However, their sharper teeth also show signs of wear and tear very quickly, and likely need to be replaced frequently. This is in contrast to sharks like the bluntnose sixgill (Hexanchus griseus,) which has a slower metabolism, and likely grows new teeth more slowly. The sixgill’s teeth don’t start out with as much of an edge as a tiger shark’s, but they also don’t get damaged as quickly. By focusing its diet on squishier animals like marine mammals, these duller teeth probably work well enough, and don’t require as much dental maintenance along the way.

The results of this tooth-test didn’t have direct comparisons to each species’ metabolism, but it does show dental strength may be a factor in these animals’ diets and behavior. And it made a mess of a lot of salmon.

Source: Shark-Toothed Power Saw Reveals Most Durable Chompers by Laura Geggel, Live Science