Nature & Environment

Stingrays Chew Their Food Too, Scientists Discover

Brooke James
First Posted: Sep 17, 2016 04:10 AM EDT

Known for their platter-like shape, stingrays are venomous creatures related to sharks. These species made it into high-profile news in 2006, when Australian "Crocodile Hunter" Steve Irwin was stabbed to death by one.

Still, the mystery of these species is not lost on scientists. A team of researchers discovered that at least one species of stingray chews their food before swallowing. The paper, published in the Proceedings of the Royal Society B, showed the ability of the creatures using high-speed video technology. This revelation is new - until now, scientist assumed that only mammals chew their food before swallowing - but there are also different definitions of what "chewing" entails. For instance, birds have a gizzard for grinding up their food, although it's a different kind of "chewing" than what they expect of mammals.

With this in mind, the research team, comprised of scientists from the University of Toronto and the University of Washington, filmed ocellate river stingrays through a tank with a see-through glass bottom. They filmed the animals as they captured three kinds of food - soft, medium, and hard - and watched as the stingrays grabbed it, chewed, and then swallowed it. Specifically, as stated by Phys.org, they found that stingrays pull their prey in by using suction made by undulating their bodies, then moving the right and left parts of their jaws back and forth to bite and tear their prey. They also found that the stingrays can move their upper and lower jaws independently, making their chewing something like mammal mastication.

With this discovery, the team suggested that chewing may not be as unique to mammals as scientists originally thought, and they are planning on studying other stingray species to see if they too, are able to chew their food.

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