A study from March 2025 reveals that the rig shark can actively produce clicking sounds, challenging long-held beliefs about sharks being unable to produce sounds and opening new doors to understanding their complex behaviors in the ocean.
Scientists reveal that the rig shark, Mustelus lenticulatus, actively produces clicking sounds underwater, marking the first documented case of deliberate sound production by a shark [1]. These clicks are loud and broadband, suggesting a potential communication or behavioral function previously unknown in sharks.
Sound plays a vital role in marine life communication. Despite teleosts being known to produce a variety of sounds, sharks and their relatives, elasmobranchs, have long been thought to lack active sound-producing abilities [2,3]. Last year, a stingray was found to produce clicking sounds, and now, a new study demonstrates the rig shark can too. This opens avenues for understanding shark behavior and communication in the ocean.
The study was conducted by a team led by Carolin Nieder from the Woods Hole Oceanographic Institution, in collaboration with researchers from the University of Liège and the University of Auckland. Their findings were published in the Royal Society Open Science journal in early 2025.
Researchers recorded sounds produced by juvenile rig sharks during handling in controlled tank environments at the Leigh Marine Laboratory in New Zealand. Using hydrophones and acoustic analysis software, they captured and characterized the clicks produced by ten sharks over 20-second handling periods, ensuring replication and standardized conditions.
The rig sharks produced an average of nine clicks during handling, with sound pressure levels averaging 156.3 dB re. 1 µPa at about 30 cm distance. These clicks had a mean duration of 48 milliseconds and peak frequencies around 9.6 kHz, with broadband energy spanning 2.4 to 18.5 kHz. The researchers propose that the clicks are generated by forceful snapping of the sharks’ flattened teeth, based on tooth morphology and acoustic characteristics.
While the study provides compelling evidence of active sound production, sharks were handled in an artificial environment, which may not fully represent natural behavior. The sample size was relatively small, and the biological significance of the clicks—whether for communication, distress signaling, or other purposes—remains to be tested in wild conditions.
These findings suggest that sharks may have more complex acoustic behaviors than previously recognized, potentially using sound for communication or defense. This could reshape our understanding of elasmobranch sensory ecology and prompt further research into their behavioral repertoire and interactions in marine ecosystems.
The discovery of deliberate sound production in rig sharks overturns a long-standing belief about elasmobranchs and highlights the need to explore acoustic communication in these ancient fishes further.
Why it matters.
Although sound production does not directly mean that sharks can communicate via sounds, the discovery of sound production capability does reveal how little we know of the social lives of sharks. Future research could use the recorded clicks to elicit behaviours in conspecifics to support the potential for communication!
References:
- Nieder, C., Parmentier, E., Jeffs, A.G., & Radford, C. (2025). Evidence of active sound production by a shark. Royal Society Open Science, 12, 242212.
- Ladich, F. (2015). Sound production and acoustic communication in fishes. Advances in Experimental Medicine and Biology, 875, 71-105.
- Myrberg, A.A., & Fuiman, L.A. (2002). The sensory world of coral reef fishes. In P.F. Sale (Ed.), Coral Reef Fishes (pp. 123-148). Academic Press.
Photo : Paul Caiger/Royal Society Open Science
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