Muscat: Researchers have recorded what they believe to be the first evidence of sharks making noise, according to newly published research. The scientists captured the sounds of New Zealand rig sharks (Mustelus lenticulatus), small sharks found in coastal waters all around the country, producing clicks when handled underwater. This is considered the "first documented case of active sound production by a shark."

According to Oman News Agency, the study involved ten juvenile rig sharks, comprising five females and five males, over an 11-month period. The sounds were recorded in an experimental plastic tank specifically set up for this purpose. The research team, led by Carolin Nieder from the Woods Hole Oceanographic Institution in the US, noted that, on average, "the sharks produced significantly more clicks" during the initial 10 seconds of handling compared to the subsequent 10 seconds.

The researchers hypothesize that the forceful snapping of the rig shark's flattened teeth is the likely source of the sound. This hypothesis is based on the rig shark's plated teeth morphology and the nature of the noise, which is characterized by its short duration (48 milliseconds) and high peak frequencies (2.4-18.5 kHz). However, the study acknowledges that further research is necessary to confirm these findings.

The biologists indicate that the purpose of the clicking sound "remains uncertain," suggesting it might be a response to disturbance or distress. They emphasize that additional behavioral research will be required to explore this aspect further.

The findings were published in the journal Royal Society Open Science.