Marine scientists have discovered that at least two different stingray species emit strange clicking noises. The recent findings caught on underwater cameras has intrigued experts and puzzled them about why and how the bottom bumping rays are chattering away.
Nearly 1,000 different fish species are known to make underwater sounds, but this is the first-time rays have been observed being vocal.
“That we only just realized that these commonly encountered stingrays are making sounds, demonstrates how little we know about the oceans,” marine ecologist Lachlan Fetterplace of the Swedish University of Agricultural Sciences is quoted by ScienceAlert.com. “We now have multiple recordings and observations of two species of stingrays making sounds in the wild.”
Mangrove whiprays and cowtail stingrays have been video recorded making odd clicking or chirping sounds that Fetterplace believes is some type of defense or warning signal for the species.
The two ray species produce different pitch noises that are clearly audible as they slide along in their near-bottom, watery world.
Scientists believe the ray-emitting clicks are detected by rays and other fish species and is meant as a warning to predators.
Rays in Australia and Indonesia have been observed clicking and chirping when approached by divers, who recorded the incidents with cameras. As the divers moved away from the rays, the sounds stopped.
How a pancake flat and fleshy critter like a ray makes underwater noises is unknown.
“They don’t have vocal cords, and there’s no clear mechanism for how they do it,” Fetterplace says.
“We can’t be certain how rays produce sounds,” marine scientist Joni Pini-Fitzsimmons of Macquarie University, says. “But it appears to involve rapid movement of the head or jaw and spiracles, an opening behind the eyes used for respiration.”
Audio recordings from video only document a few stingray species making sounds. With about 200 species of rays gliding in various parts of the world, it’s possible many are silent, solitary critters.
“They can be quite difficult to study because they are often highly mobile and elusive,” Audrey Looby, a marine ecologist at the University of Florida said to National Geographic.