Mike Kelly, a researcher from Simon Fraser University, Burnaby, British Columbia, Canada, for the first time found the first physiological evidence that sharks also sleep. Unlike the sleeping habits of other marine animals, Sharks only sleep for a moment, even just a few blinks of an eye.
This fact finding was published this week in Biology Letters. Kelly and researchers observed the sharks for 24 hours by tracking their metabolic rate and behavior during swimming, rest, and sleep periods.
Read also; Why Do Sharks and Whales Swim Different?
The study found that sharks resulted in a lower metabolic rate and a supine posture when inactive for more than five minutes. This fact supports the idea that Sharks conserve energy by sleeping.
“Sharks show a dramatic decrease in their metabolic rate and a clear change in posture after five minutes of inactivity. This shows a clear separation between periods of wakefulness and restful sleep,” Kelly said. .
While it is known that many animals sleep, including bony fish species, Kelly said the study provides the first physiological evidence of sleep among elasmobranch species, a group of fish that includes sharks, and rays.
Read also; Leopard Seals Proven Capable Of Eating Sharks
Kelly previously studied sleep behavior among crocodiles for her Honors thesis at Australia’s La Trobe University. The study – which found that these creatures likely slept with one eye open – was later published in the Journal of Experimental Biology.
–
