This shark can hold its breath to stay warm in the deep, study finds | 24CA News

In a behaviour by no means earlier than seen in fish, scientists have found that scalloped hammerhead sharks will maintain their breath to remain heat as they hunt for squid in frigid waters 1,000 metres beneath the ocean’s floor.

“I would have never, ever have expected a gill-breathing fish to resort to holding its breath to dive down deep in the ocean,” stated Mark Royer.

Royer was a part of a workforce of researchers from the Hawai’i Institute of Marine Biology who made this discovery working with sharks close to the Hawaiian island of Oahu.

The examine was revealed this week within the journal Science. 

Scalloped hammerhead sharks dwell in heat, tropical waters all over the world and are ectothermic, which suggests their physique temperature modifications with their speedy surroundings.

But if the shark’s physique temperature drops, so does its metabolism and exercise stage, slowing down the shark and making it a much less efficient hunter.

Royer stated some “high performance” fish, like tuna and mackerel sharks, have specialised anatomy that enables them to heat components of their physique after they hunt in chilly water. But there is not any proof that scalloped hammerheads have this. 

Deep dives

Royer and his workforce tagged sharks with sensors that allowed them to observe swimming exercise, physique temperature and the properties of the surroundings they swam by way of, together with water temperature and depth.

Despite diving from 26 C to five C, which is “about the same as an ice-bath,” in keeping with Royer, the sharks had been in a position to keep a comparatively heat physique temperature. 

Royer stated chilly water ought to have flown by way of their gills, inflicting their physique temperature to drop. 

“So for any fish … the detriment for swimming in cold water is that when you have gills, it’s like having a giant radiator strapped to your head,” he stated. 

“If your water temperatures are colder than the fish’s body, all of that heat will be dumped into the environment.”

Royer discovered that the easy resolution for the sharks was to simply shut their gills to forestall the chilly water from flowing by way of. This prevented them from dropping physique warmth.

“When they start to … dive down to the bottom, they close the flaps, shoot straight down very quickly, eat what they can, and when it’s time to go up, they pitch themselves at a steep angle and burst up towards the surface,” Royer stated.

The sharks maintain their breath for roughly 17 minutes, however Royer says his workforce is not positive how they handle to go with out oxygen for thus lengthy.

So far, scalloped hammerhead sharks are the one identified species to exhibit this behaviour, however Royer thinks different species may use comparable methods.

For instance, the oceanic whitetip shark lives in tropical environments, but additionally dive into deep, chilly waters.

“That’s something that needs to be investigated in a further study,” he stated. “It’s possible that they have really well-suited physiology and metabolism to be able to do such intense exercise with a lack of oxygen.”

Royer stated additional analysis is required to grasp if different animals use comparable methods.

Written and produced by Shazara Khan