Stingrays Eat Food That Is Harder Than Their Own Jaws

If you’re ever in the Xingu River (a tributary of the Amazon River) in Brazil, look into the fresh flowing water! You might spot one of the endemic spotted rays that call this area home- the Xingu River stingray (Potamotrygon leopoldi). Not only are they unique because they are brilliantly colored and in fresh water, but they are part of an unusual group that eat prey that is tougher than their own jaw. This feeding method is call durophagy, and the fishes that consume these hard-shelled animals have evolved this…

Read More

Freshwater stingrays chew their food just like a goat

A new University of Toronto study has found that some freshwater stingrays from the Amazon chew their food in a similar fashion as mammals. Using a combination of high-speed video and CT scans Matthew Kolmann, a recently graduated PhD in the lab of U of T Scarborough’s Nathan Lovejoy found that as the freshwater stingray Potamotrygon motoro eats it protrudes its jaws away from its skull, shearing from side to side in the process. “It’s pretty extraordinary when you think about it — here’s this bizarre-looking fish from the Amazon…

Read More