Stingrays Discovered Producing Strange Clicking Noises Despite Being Silent

Captured on camera, two different species of stingrays have recently been discovered, producing weird clicking sounds in a fortunate discovery that has brought delight to marine ecologists, but left them stumped, as well.

As specified in a ScienceAlert report, stingrays are not silent residents of the sea anymore that scientists once believed them to be.

According to marine ecologist Lachlan Fetterplace from the Swedish University of Agriculture Sciences who led the research, they only "just realized that the commonly encountered stingrays are making sounds" shows once again, how little is known about the oceans.

More than 900 species of bony fish are known to create sounds. However, elasmobranchs, a group of cartilaginous fish that includes rays, sharks, and sawfish, were always believed to be the silent, stealthy type.

Producing Sounds in the Wild

Fetterplace explained, that they now have multiple recordings and observations of two stingray species producing sounds in the wild, because of a few avid naturalists.

Specifically, two mangrove whiprays also called Urogymnus granulatus, and one cowtail stingray also called Pastinachus ater, were observed by divers who caught them making strange sounds, which possibly serve as a warning or defense signal, explained Fetterplace.

Different from haunting whale songs that travel far through the oceans, or bewitching bird songs filtering through forests, the wild stingrays in the videos are seen and heard making brief, sharp hollow-sounding clicks and sound more like a percussion instrument compared to a marine animal.

Based on slightly known information about the range of sounds elasmobranchs can hear, Fetterplace and the team surmised that the stingrays and their predators can definitely hear such clicking sounds, falling into the expected hearing range.

This led the researchers to propose that stingrays might make the sounds to ward off or stun approaching predators, so the rays can create a quick getaway.

Making Sounds Without Being Provoked

Essentially, stingrays' noises have been observed before, also only infrequently. Decades ago, a few captive rays were spotted making "rumbling" and "crunching" sounds when feeding.

There were some anecdotal accounts of cowtail stingrays producing loud clicking sounds when fleeing from divers dark waters.

This nonetheless, appears to be the first recorded evidence of the animals actively making sounds minus being provoked.

More studies are needed though, to appreciate the elasmobranchs' hearing range, especially considering the limited number of investigations in this group until now, wrote the researchers in the study published in the journal, Ecology.

Elasmobranchs Most Sensitive to Low-Frequency Sounds

Elasmobranchs, Fetterplace explained, are the most sensitive to low-frequency sounds between 40 and 1,500 Hz, with peak sensitives from 200 to 300 Hz, although audiograms have been produced for 10 species.

Considering how animals sense the worlds they are inhabiting in ways that cannot really ever be truly fathomed, the marine ecologist said they shouldn't be surprised yet continually marvel at new finds that "upend what we thought" about life on Earth.

The videos were able to catch just a few instances of a pair of stingray species producing noise, which might be since they only do so very occasionally when they are threatened. Some stingray species are solitary creatures.

In a National Geographic report, marine community ecologist Audrey Looby, from the University of Florida who was not part of the work said they can be quite difficult to study as well, as they are frequently highly mobile and elusive.

Despite the challenge, with more than 1,200 known elasmobranch species, the study investigators think many more observations could surface soon, now that humans know what they ought to listen out for.

Report about the stingrays making weird sounds is shown on Fish Thinkers Research Group's YouTube video below:

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