shark facts

WTF Fun Fact 13514 – Cuddly Sharks Sleeping

by

National Geographic gave us a unique look into the little-known habit of “cuddly” sharks sleeping together.

Of course, when one thinks of a shark, the image that often comes to mind is that of a fierce predator. The last thing you’d imagine is a creature with “cuddly sleep habits.” But what if the way sharks rest and sleep is more fascinating than you might believe?

Understanding Sharks Sleeping

Unlike humans, sharks don’t have eyelids, so it’s challenging to determine when they’re asleep or awake by merely observing them. However, that doesn’t mean they’re always on the prowl. Sharks have periods of rest and activity, but their “sleep” is different from what we typically understand.

Most sharks need to keep moving to breathe. Water flows over their gills, providing them with the necessary oxygen. This phenomenon might make it seem like sharks never rest, but that’s not entirely true.

Do Sharks Really Sleep?

The concept of sleep in sharks is intriguing. Some species have been observed to enter a state called “tonic immobility.” This natural state of paralysis, which can last for minutes, isn’t sleep in the traditional sense. Instead, it’s more of a trance-like state where the shark becomes incredibly still and can be handled without reacting. It’s not entirely understood why sharks enter this state, but it’s believed to be a defense mechanism.

While the idea of sharks being “cuddly” is a stretch, some species do exhibit social behaviors that might surprise you. For instance, the Spotted Wobbegong, a type of carpet shark, has been observed resting in groups, often piled atop one another, almost like a group cuddle!

While this behavior is more about conserving energy and space than seeking comfort, it’s an endearing sight that shatters many shark stereotypes.

Adaptable and Ever-Evolving

The world of sharks is vast, with over 400 species, each with its unique habits and idiosyncrasies. Some species have evolved specialized methods to rest while maintaining their oxygen flow. The Spiracle, an organ located just behind the eyes of some sharks, allows them to draw water while being stationary. This adaptation enables species like the Whitetip reef shark to lie on the ocean floor and rest without constantly swimming.

While “cuddly” might be a whimsical way to describe the rest habits of sharks, there’s no doubt that these majestic creatures of the deep have a side to them that’s less understood and more fascinating than their fearsome reputation suggests.

—WTF fun facts

Source: “Rare Footage Shows the Cuddly Sleeping Habits of Sharks” — Mental Floss

WTF Fun Fact 13460 – Sharks in a Lake

by

There’s nothing quite like the ocean. But you can get some beach time in at the lake as well. It used to be a shark-free way to enjoy the water. But not anymore since there have been more than a few reports of sharks in a lake!

If you’ve swum in certain lakes around the globe, you might have shared a swim with these fascinating creatures.

Bull sharks are freshwater fans

While Great Whites may not make an appearance in our freshwater lakes, bull sharks, notorious for their ability to survive in both salt and fresh water, do make an appearance. This survival trick is all thanks to their advanced ability to osmoregulate their livers. This allows them to adapt to varying salinity levels, unlike their fellow hammerhead or tiger sharks.

One of the largest freshwater lakes in the Americas, Lake Nicaragua, sees these adaptable creatures as regular inhabitants. The bull sharks make their way through the San Juan River. They successfully navigate through eight rapids, much like salmon, to reach the lake and may reside in the lake for several years.

They exhibit some impressive rapids-navigation abilities not seen in other bull shark populations.

Unexpected sightings of sharks in a lake

Even a seemingly innocent round of golf can turn into a shark encounter at Queensland’s Carbrook Golf Club in Australia. In 1996, a massive flood seems to have left around six bull sharks trapped in the golf course’s freshwater lake. Since then, the shark population has been a consistent feature of the club.

The bull shark presence is not limited to Australia or the Americas. In Lake Pontchartrain, Louisiana, bull sharks have been spotted and even caught by anglers. A boy was reportedly attacked by a bull shark in 2014 in this lake. The sharks are known to venture more into the lake during the summer. But they retreat back to the Gulf of Mexico towards the year-end.

These fascinating creatures have also been observed in Lake Janoer in New Guinea. Oh, and you might see one in Lake Izabal in Guatemala, Lake Sentani in Indonesia, and Lake Bayano in Panama. (But note that despite a few shark sighting being reported in the Great Lakes, such as Lake Michigan, those have never been scientifically confirmed.)

In a more heartwarming encounter, Lake Maracaibo in Venezuela is home to a bull shark nursery. However, this particular lake may not be the best holiday destination. It holds the world record for the highest number of lightning strikes.

Freshwater lakes aren’t always shark-free

A river swim doesn’t eliminate the risk of encountering a shark. Three species of river sharks exist: the Ganges shark, the northern river shark, and the speartooth shark. These aquatic creatures can be found in the freshwater rivers in India and the brackish estuaries in northern Australia and New Guinea.

But don’t freak out (despite Summer 2023 being the year the ocean seems to be fighting back). It’s essential to remember that shark attacks, whether in the sea or a lake, are exceedingly rare. In fact, have a better chance of being bitten by a New Yorker than a shark!

—WTF fun facts

Source: “Shark-Infested Lakes Exist And You Might Have Already Swum In One” — IFL Science

WTF Fun Fact 13453 – Shark GPS Tracker Draws Shark

by

A great white shark with a GPS tracker drew a shark in the waters off the eastern coast of North America. Was he “punking” researchers? Telling us he knows what we’re up to? Do sharks mysteriously swim in shark-shaped patterns? Or are we just seeing what we want to see?

Don’t answer that – it’s not as funny if you do.

The unconventional artist

Art and creativity are typically deemed human endeavors. But perhaps they also belong to the great white shark who unwittingly sketched a self-portrait, using tracking data as its brush.

Our artist is a mature male great white shark, named Breton by the OCEARCH team. He’s a frequent wanderer off the Atlantic Ocean coast of Long Island, New York. As part of the shark tracking initiative, he carries a tracker affixed to his dorsal fin. This tracker collects and relays data whenever the shark surfaces, providing an almost real-time map of the shark’s movement.

Did the shark GPS tracker draw a shark?

A May 2022 observation of Breton’s tracking data offered an unexpected delight to the researchers. It seemed as though Breton had swum in a pattern that mirrored the outline of a great white shark when seen from above.

OCEARCH shared the data on its social media, and the internet quickly took notice.

The tracking path captured not only the body’s curve but also the classic angular shape of the tail and the pectoral fins. It sure looks like a shark!

Coincidence or Design?

As fascinating as Breton’s journey may seem, it is essential to underline that the ‘self-portrait’ was purely coincidental. Sharks navigate based on instincts and sensory information, not a predetermined design. Sorry if you needed to be told that – but people have been studying sharks for a long time. That doesn’t mean we can’t enjoy the coincidence!

While the artistic byproduct is captivating, the primary purpose of tracking sharks like Breton is conservation. By learning about migration patterns, feeding areas, and breeding grounds, scientists can devise effective strategies to safeguard these creatures. The knowledge gained from such tracking can inform the establishment of marine protected areas and fishing regulations.

The good news is that Breton’s self-portrait can serve as a symbol for raising awareness about the threats facing great white sharks.

Issues like overfishing, habitat degradation, and climate change pose significant threats to these magnificent creatures. Breton’s story is an opportunity to engage the public and rally support for shark conservation.

—WTF fun facts

Source: “Great White Shark Accidentally Draws Self-Portrait With Tracking Path” — The Inertia