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Snakes aren’t just muscle-y danger noodles. They're extremely diverse, and some have really weird, unique adaptations that we could all probably appreciate a little more.

Hosted by: Hank Green

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Sources:

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https://commons.wikimedia.org/wiki/File:Aipysurus_laevis00.jpg
[♪ INTRO].

Here at SciShow, we love snakes. We’ve got episodes on venomous snakes, and poisonous snakes, and we’ve even had some on SciShow as Talk Show guests.

But you might still think all snakes are basically the same. You know, like, they’re all just, like, this slender, muscular danger noodle. So in this episode, we want to pay special tribute to the incredible diversity of these legless creatures.

We’re going to talk about 6 snakes with some extraordinary features. Hognose snakes get their affectionate name from their enlarged rostral scale, which is the plate at the front of a snake’s nose. That gives them their upturned noses which make them look, you know, kind of cutely pig-ish.

And kinda like a pig’s snout, their little snoots are great for rooting around in the soil. The upturned nose acts as a shovel to move soil or sand out of the way as they make a safe burrow. The snakes will bend their heads downwards and then wiggle them from side to side.

At the same time, their bodies move in wave-like motions to help them sink below the dirt. Those piggish noses also help them find food. They eat everything from lizards to small mammals, but a nose for digging helps them most if they’re looking for frogs and toads that spend part of the year underground.

Their fangs, which, like other rear-fanged snakes, are located further back in their jaws than front-fanged snakes, are long and smooth, so some scientists thought that they might be used for popping toads that inflate themselves as a defense mechanism. But a scientist back in 1976 measured how long the fangs would need to be, 1.38 cm on average, in case you were wondering, which is much longer than the fangs actually are. They’re only about 0.3 - 0.5 cm.

The hognoses’s unique hiding and hunting behavior is pretty cool, but they have another trick up their scaly sleeves. When they feel threatened, they’ll roll over on their backs and play dead, also called death feigning. And hognoses really get into this dramatic act.

They will writhe around and stick out their tongues until whatever scared them is gone. Way back in 1974 scientists noticed the snakes’ heart rate would also drop while death feigning from around 50 to 80 beats per minute to between 3 and 15 beats. That is some dedication as a method actor!

Stiletto snakes might sound fashionable but that name isn’t because they have good taste in high-heels. They are a burrowing group of snakes found mostly in sub-Saharan Africa. There, they inhabit everything from deserts to rainforests.

And they’re best known for their long, knife-like fangs that allow them to stab prey without opening their mouths. Most snakes strike when their potential meal is right in front of them—but not stiletto snakes. They’ll slide up past an unsuspecting skink, lizard, gecko or mouse and then whip their head backwards to lodge one of those long fangs in the prey.

It’s such a unique movement done at close range that some scientists prefer calling it “fang stabbing” rather than striking. And it might sound like a weird way to hunt, but it’s actually really useful as it lets the snakes capture prey in tight spaces like tunnels or burrows. It also allows them to release the prey really quickly, because they don’t have their whole mouth wrapped around it.

And that’s important because some of the stiletto snakes’ prey, like scaly lizards, tend to fight back. So they want to get in, deliver some venom, and then back off until the toxins have done their job. In fact, the snake’s entire mouth is specifically adapted for this weird attack.

Stiletto snakes have a short jaw bone, fewer teeth, and a snout that’s tightly attached to the rest of the skull so the jaw stays clamped closed when it’s wiggling through tight spaces. But this awesome ability and anatomy has its downsides. Stilettos lack the teeth needed to do the usual pterygoid walk to swallow their prey.

That’s where a snake will open its mouth and use specific teeth to hook and then pull prey into its mouth step by step. Which makes sense if you don’t have, like, hands to shovel food in your mouth, like, awww, I do. And even if they had those teeth, their jaws don’t open wide enough to swallow food that way.

So stilettos have to do a weird head wiggling action where they shift their jaw backwards, flex their head down toward their belly and squeeze their trunk forward, then shift their jaw and head forwards over their prey. It sounds pretty awkward if you ask me. And according to scientists this is pretty much as extreme as this adaptation can get.

Basically it can’t really improve upon its unique strike without sacrificing the ability to eat. The Pseudocerastes snakes of the Middle East range from southern Israel, through Iraq, southwestern Iran and Afghanistan and Pakistan. They get their scientific name from the false horns on the top of their heads, but it’s what’s on the other end of the snake that’s more interesting.

You see, vipers are ambush predators. They select a good hiding place and then wait for prey to come by. Even with the perfect location, though, it can take a bit of time for the right meal to get close enough, so these vipers wag their tails around as a lure to draw their prey in.

And one of these snakes, the Iranian spider-tailed viper, has arguably the most elaborate tail lure of all. Most of its grayish brown body blends in almost perfectly with the gypsum rocks common to its habitat. But its tail looks just like a spider, and with some careful jiggling back and forth, it would probably have you fooled too.

But don’t worry, it’s birds that this spider is after. The good news is that I, personally, am not ever attracted to a spider on the ground, so I’m probably not gonna get lured in by this. But birds do have to be worried.

These snakes seem to mainly hunt larks, shrikes and warblers, but have also been known to catch the odd gecko, too; basically anything that goes for that tempting tail. But, there are some issues with a lure that is so convincing. Researchers have found snakes with damaged tails, presumably because some birds actually bit the “spider”.

It’s unclear whether this makes the snakes any worse at luring in prey. But I bet it doesn’t feel too great to have part of your tail bitten off! Hunting underwater comes with an entirely different set of challenges than the snakes that we’ve talked about so far.

Like for example, finding your prey when the water is slow moving or not very clear, or striking with enough power to counteract the resistance of the water. But the tentacled snake seems to make light work of it. This species can be found in slow moving rivers and murky ponds in southeast Asia, where it feasts almost exclusively on fish.

The snake will sit motionless in the water in a kind of J shape and wait for fish to approach. It will then move sections of its body to herd the fish up towards its jaws. When the fish is positioned in a little crook between the snake’s head and body, the snake will whip its head sideways to strike, turning its head to meet the fish front on at the last moment.

This is different than most other snakes, which coil up their bodies and strike forwards. The tentacled snake will even preempt the fish’s escape. It strikes where the fish will be, not where it currently is.

Though scientists aren’t yet clear whether it’s back and forth evolution between predator and prey or individual experience that led to such smart targeting. The snakes possess some awesome features that facilitate this unique attack. Probably the most distinguishing one is those little tentacles that jut out from the sides of the snake’s nose.

They are highly sensitive to changes in water around them. They’re stuffed full of nerves that send signals to the snake’s brain when anything within a two centimeter radius of them moves. That’s exactly how close a fish is when the snake would want to strike.

The snake’s shallow, flattened skull is thought to help it hunt underwater because it minimizes drag as the snake strikes, allowing it to attack with the same, or even more force, as land snakes. That’s pretty remarkable considering it’s pushing against water instead of air. It also helps that the snake can engulf the water ahead of it when it strikes instead of pushing it out of the way.

Now, you may tremble at the idea of any snake slithering towards you, but what if the snake was, like, flying through the air? So-called flying snakes of the genus Chrysopelea are sometimes called the only limbless vertebrate flyers. But flying is a misnomer.

They’re actually gliding. I’m not any less scared of them. These tropical southeast Asian snakes will launch themselves off a high perch, slither through the air to land some 8 to 16 meters away.

That’s pretty impressive given the snakes are only around half a meter to just over a meter in length. In the mid 2000s, scientists filmed the paradise tree snake species as they launched themselves from a platform, and then reconstructed those jumps in three dimensions, to figure out exactly how the snakes were moving. Let’s start with takeoff, which is kind of a hard thing to do without legs to push with!

So, the snakes make a J shape with the front part of their bodies while hanging from their tails, and launch themselves that way. They then enter a falling phase for a short while before leveling out and gliding, all the while undulating their bodies in a complex side to side pattern. They can even turn in midair!

Talk about falling with style! And this movement is pretty different from what snakes do on the ground so scientists think that this special wiggling might help them generate lift or stabilize them while gliding somehow. Some of their ability to glide also comes from the way the snakes flatten their bodies horizontally once they’re in the air.

The flattening functionally turns their bodies into a wing, which separates the air in front of it into two streams: one above the body and one below. The difference in pressure between the air that goes under the snake and over the snake can generate lift, just like an airplane wing! But scientists aren’t 100% sure why these snakes “fly”.

It’s not more energy-efficient than wiggling along the ground, but it is quick so it might help them escape predators better. Either way, if you see one of these snakes slithering towards the end of a branch,. I would move out of the way.

The olive sea snake spends its time swimming around the coral reefs of Northern Australia,. Papua New Guinea, and New Caledonia using its paddle-like tail to propel itself through the water. Its long, skinny body lets it squeeze into crevices in search of crabs, prawns, fish eggs and fish.

But it’s not the only hunter in these waters, so it often ducks into those same crevices to hide. In fact, aside from surfacing for air, courting a mate and, of course, nabbing some food, they usually spend their time trying to fit as much of their 1.2 meter long body in coral as they can. There’s only one problem with that.

If the snakes’ tail peeks out, it risks getting chomped on. So the olive sea snake has evolved a really neat way of keeping an eye on its tail. Literally.

The skin on its tail can sense light, which means the snake can adjust if it “sees” its tail sticking out. Scientists first studied this ability in the late 1980s when they kept ten snakes in a darkened lab tank. They noticed that the snakes pulled their tails in when researchers shined a fiber optic light on them.

This phototactic response only worked when the light shone on the tip of the tail not the part closer to the rest of the body. Then, in a study published in 2019, researchers looked to see if other sea snakes also had this ability. They found that two other species of sea snake showed a similar response to light, and since they were close relatives of the olive sea snake, the researchers concluded that this ability probably evolved in their common ancestor.

That may mean that 10% of all sea snakes sense light with their tails! By using RNA sequencing, the scientists figured out that their tail skin expresses genes which code for a light sensitive protein called melanopsin and also other proteins involved in how light receptors sense light levels, which might explain how they actually “see” with it. So you see, snakes aren’t just muscle-y danger noodles.

Whether it’s being a really talented actor, gliding between trees or having a tail that looks like a spider, snakes are super diverse. And hopefully, understanding these animals and their weird, unique adaptations will help us all appreciate them a little more. Thanks for watching this episode of SciShow!

We put out educational science videos like this every day, so be sure to click that subscribe button to get them all into your feed. And if you liked learning about these awesome snakes, you’ll probably love our episode on 7 uniquely fierce sharks! I mean, I’m not, like, telling you what to do or anything, but if it were me, I’d watch that one next. [♪ OUTRO].