CLOSE

7 Cool Facts About the Greenland Shark

This week, video popped up of a researcher freaking out after he spotted a rare Greenland shark on footage he had downloaded from a remote camera in the Russian arctic (you can watch the hilarious video above). Here are a few things you might not have known about this elusive deep sea denizen. 

1. The first part of its scientific name, Somniosus microcephalus, roughly translates to “sleep,” because of the shark’s slow swimming; the second part of its name means “small head” (pretty self explanatory). In addition to Greenland shark, it’s sometimes called a sleeper shark or a ground shark, and it goes by a number of other names as well: In Greenland, its names include ekaluggsup piara, ekaluksuak, eqalussuak, and eqalusuak; in the Netherlands, South Africa, and Turkey, it’s called hakaring; in Italy, it's called squalo di groenlandia lemargo; and it’s referred to as tiburon boreal in Spain.

2. It’s one of the largest living sharks. At 6.5 feet long, the one seen above was probably very young; on average, they grow to 14 feet, and can get as large as 21 (or maybe 24) feet. But they grow slowly, at an average rate of a quarter-inch a year. The females are bigger than the males. 

3. Greenland sharks might live as long as 200 years!

4. Its meat is toxic—at least if you eat it fresh. Its flesh contains high concentrations of trimethylamine oxide (TMAO), which “helps stabilize [the shark’s] enzymes and structural proteins against the debilitating effects of cold and extreme pressure,” according to the ReefQuest Center for Shark Research. In mammals, though, TMAO gets broken down during digestion and causes a number of horrible symptoms, including “stiff movements, hyper-salivation, vomiting, explosive diarrhea, conjunctivitis, muscular twitching, respiratory distress, convulsions, and—in severe cases—death.”  It also makes people appear as though they’re drunk, which is why, according to the Florida Museum of Natural History, natives of Greenland say that people who are drunk are “shark-sick.” The Greenland shark’s flesh is so toxic that it earned a spot in Guinness World Records 2013, but it can be consumed if it’s prepared properly: It either needs to be boiled with several changes of water, or buried for as long as 12 weeks so that it freezes and thaws several times, then hung up to dry for a few months. The resulting snack is called hákarl; according to the Wall Street Journal, chef Anthony Bourdain called it "the single worst, most disgusting and terrible tasting thing" he's ever eaten.

5. The Greenland shark will eat pretty much anything, dead or alive. Though it mostly feeds on other fish—including small sharks, eels, lumpfish, and flounder—some specimens have been found with entire reindeer in their stomachs. One was found containing a juvenile polar bear's jaw, and this shark was found choking on a moose hide.

6. In the deep ocean where the Greenland shark typically lives—it’s been spotted as deep as 7220 feet—it doesn’t need great vision. And that’s a good thing, considering that these sharks are hosts for Ommatokoita elongata, a 2-inch-long parasitic copepod that attaches itself to the shark’s eyes, causing lesions that can lead to blindness. According to Daily Parasite,

The adult female copepod attaches herself to the shark's eye with an anchoring structure call the bulba, and grazes on the surface of the cornea. … There are two possible reasons for the copepod's attachment site. Shark skin is covered in microscopic, teeth-like structures call denticles which can make it difficult for parasites to attach themselves to skin (though some species of parasitic copepods manage). Secondly the eye is considered to be a "immunologically benign environment" for parasites, thus such an attachment is less likely to illicit an immune response.

It sounds gruesome, but the sharks don’t seem to mind; some even have copepods in both eyes.

7. It has crazy teeth. On the top jaw, they’re thin and pointed, without serration. The teeth on the lower jaw are broad, square, and interlocking with short, smooth, outward-pointing cusps. The top teeth serve as anchors while the bottom teeth do the cutting.

nextArticle.image_alt|e
iStock
arrow
Animals
Where Do Birds Get Their Songs?
iStock
iStock

Birds display some of the most impressive vocal abilities in the animal kingdom. They can be heard across great distances, mimic human speech, and even sing using distinct dialects and syntax. The most complex songs take some practice to learn, but as TED-Ed explains, the urge to sing is woven into songbirds' DNA.

Like humans, baby birds learn to communicate from their parents. Adult zebra finches will even speak in the equivalent of "baby talk" when teaching chicks their songs. After hearing the same expressions repeated so many times and trying them out firsthand, the offspring are able to use the same songs as adults.

But nurture isn't the only factor driving this behavior. Even when they grow up without any parents teaching them how to vocalize, birds will start singing on their own. These innate songs are less refined than the ones that are taught, but when they're passed down through multiple generations and shaped over time, they start to sound similar to the learned songs sung by other members of their species.

This suggests that the drive to sing as well as the specific structures of the songs themselves have been ingrained in the animals' genetic code by evolution. You can watch the full story from TED-Ed below, then head over here for a sample of the diverse songs produced by birds.

[h/t TED-Ed]

nextArticle.image_alt|e
NOAA, Wikimedia Commons // Public Domain
arrow
Animals
Watch the First-Ever Footage of a Baby Dumbo Octopus
NOAA, Wikimedia Commons // Public Domain
NOAA, Wikimedia Commons // Public Domain

Dumbo octopuses are named for the elephant-ear-like fins they use to navigate the deep sea, but until recently, when and how they developed those floppy appendages were a mystery. Now, for the first time, researchers have caught a newborn Dumbo octopus on tape. As reported in the journal Current Biology, they discovered that the creatures are equipped with the fins from the moment they hatch.

Study co-author Tim Shank, a researcher at the Woods Hole Oceanographic Institution in Massachusetts, spotted the octopus in 2005. During a research expedition in the North Atlantic, one of the remotely operated vehicles he was working with collected several coral branches with something strange attached to them. It looked like a bunch of sandy-colored golf balls at first, but then he realized it was an egg sac.

He and his fellow researchers eventually classified the hatchling that emerged as a member of the genus Grimpoteuthis. In other words, it was a Dumbo octopus, though they couldn't determine the exact species. But you wouldn't need a biology degree to spot its resemblance to Disney's famous elephant, as you can see in the video below.

The octopus hatched with a set of functional fins that allowed it to swim around and hunt right away, and an MRI scan revealed fully-developed internal organs and a complex nervous system. As the researchers wrote in their study, Dumbo octopuses enter the world as "competent juveniles" ready to jump straight into adult life.

Grimpoteuthis spends its life in the deep ocean, which makes it difficult to study. Scientists hope the newly-reported findings will make it easier to identify Grimpoteuthis eggs and hatchlings for future research.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios