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Barry Peters via Flickr // CC BY 2.0
Barry Peters via Flickr // CC BY 2.0

10 Stunning Facts About Stingrays

Barry Peters via Flickr // CC BY 2.0
Barry Peters via Flickr // CC BY 2.0

If you’re unsure about your stance on stingrays, we don’t blame you. They’re often portrayed as deadly, cold-blooded creatures who wield their venomous tails like a murder weapon. They're also oddly adorable. The best way to form an opinion is by learning a little more about the mysterious stingray. Here are 10 facts about these saucer-like creatures of the deep.

1. STINGRAYS ARE FISH. 

Roberto Machado Noavia Getty Images

Though they may not resemble the finned friends in your fish tank at home, stingrays belong to a group of fish called elasmobranchs. There are around 200 different stingray species in total.

2. STINGRAYS ARE CLOSELY RELATED TO SHARKS.

Qldian via iStock

Stingrays and sharks belong to the same group of cartilaginous fish. This means that instead of bones, they’re supported by skeletons of cartilage. Like sharks, stingrays use sensors called ampullae of Lorenzini to sense the electrical signals emitted by their prey. These sensors are located around their mouths, and they compensate for the stingray's poorly-placed eyes.

3. STINGRAYS HAVE BEEN AROUND FOR A LONG TIME.

Kyle Durigan via Flickr // CC BY-NC-ND 2.0

Fossil records of the first rays date back to the Lower Jurassic Period (about 150 million years ago). By the Paleocene Era just 100 million years later, all major taxa of rays had been established. Stingray fossils are hard to come by due to their lack of bones, and some of the only evidence they’ve left behind are scales and teeth. 

4. STINGRAY VENOM WAS USED AS AN ANESTHETIC.

Amit Chattopadhyayvia Wikimedia Commons // CC BY 2.0 


While painful, stingray venom isn’t usually deadly unless victims are stung in the chest or abdomen. In ancient Greece, venom was actually extracted from stingray spines for the purpose of being used as an anesthetic by dentists.

5. THE BIGGEST STINGRAY WEIGHS NEARLY 800 POUNDS.

Acquarious Sea Tours via Flickr // CC BY-NC-ND 2.0

Short-tailed stingrays, known as Dasyatis brevicaudata, are found off the southern coasts of Africa and Australia. They can reach 770 pounds in weight and grow 14 feet in length. The giant freshwater stingray (Himantura chaophraya) grows to be quite monstrous as well. In March, fisherman in Thailand’s Mae Klong River caught a 14-foot stingray that weighed between 600 and 800 pounds. It was one of the largest freshwater fish ever captured.

6. STINGRAYS AREN'T NORMALLY AGGRESSIVE. 

Elena Kalis via Flickr //CC BY-NC-ND 2.0

While a run-in with a stingray has the potential to be deadly, they normally act kind and gentle around humans. It’s only when a stingray feels threatened that divers have a reason to worry. Most stingrays attack when a diver is swimming directly over or in front of a ray, blocking its escape route. Accidentally stepping on a ray in shallow water is also a fast way to get stung. Expert divers shuffle their feet when entering the ocean to avoid stepping directly on a stingray’s back.

7. STINGRAY JAWS CAN CRUSH MOLLUSK SHELLS.

VirtualWolf via Flickr // CC BY-SA 2.0

Even though they’re cartilaginous, stingray jaws are strong enough to crush rock-hard clam shells. The calcified cartilage in their jaws is several layers thick, and the softer cores of their jaw elements are supported by hollow, mineralized struts. This makes stingray jaws strong and lightweight at the same time.

8. SOME STINGRAYS MOVE LIKE A WAVE, OTHERS LIKE A BIRD.

SnapperCR29 via Flicker// CC BY-NC-ND 2.0

Most stingrays swim through the ocean by undulating their bodies in a wave-like motion. Others will flap their sides up and down, giving them the appearance of “flying” through the ocean like a bird.

9. STINGRAYS ARE GOOD AT HIDING.

Jeff Kraus via Flickr// CC BY-NC 2.0

Next time you go for a walk through the ocean’s shallow waters, remember that stingrays spend most of their time hiding in the sand. Their mottled skin, ranging from a light sandy tone to a dark brown, gives them the perfect camouflage for chilling out on the sea floor until a tasty meal comes their way. It also keeps them hidden from predators of their own like killer whales and hammerhead sharks. To add an extra element of protection, stingrays will stir up sand with their wings while burying themselves head-first.

10. STINGRAYS ARE BORN FULLY-FORMED.

Little Peppercorn via Flickr // CC BY-NC-ND 2.0

When baby stingrays are born they look like miniature versions of their parents. They are fully-proportioned and naturally good swimmers from birth. This helps them find food on their own right away, though mothers still stick around to provide protection until around age three or so. Did we mention they also look like adorable raviolis?

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Animals
Where Do Birds Get Their Songs?
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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]

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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.

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