Daily Shark Fact - 4/30/2025
Today's shark is the Japanese sawshark!
The basics: one of the better-known species of sawsharks, the Japanese sawshark (Pristiophorus japonicus) is still poorly understood. They may vertically migrate up and down the water column, but are primarily deep-water sharks found on the sandy bottoms of the continental shelf. Like all sawsharks, they have ampullae of Lorenzini (which detect electromagnetic changes in their environment) placed along theri saw-shaped rostrum, which they can move over the seabed to locate prey, kind of like a metal detector!
Conservation status: least concern. Information on population size and bycatch frequency is unknown, and Japanese sawsharks rarely come into contact with humans.
Today's fun fact: do you know how to tell sawsharks and sawfish apart? Sawfish are actually rays, related to sharks, and they look a lot like sawsharks but it's just an example of convergent evolution. Sawsharks are deep-water sharks and are rarely seen, while sawfish are shallow coastal rays and are very commonly found in public aquariums. Sawsharks, unlike sawfish, also have a pair of long barbels on their saw, their saw is a bit pointy, and the "teeth" on their saw alternate between being large and small (unlike the equally-sized teeth on a sawfish's rounded saw). Another easy way to tell: like all rays, sawfish have their gills on their underside, and sawsharks have gills on their sides.
