The Unspeakable Horrors of the Deep Sea (ft. LindsayNikole) 

Zeus: Can you imagine living among humans? Hades: Try living among dead humans. Poseidon: That's cute...

when I was a kid, they used to tell me that fearing deep sea creatures was stupid. Casual Geo made me realize it's actually not so stupid

It's crazy how alien these creatures look. Makes you really understand just how different the environment is down there, where these body designs would be the best fit, something that would never succeed anywhere close to the surface.

I'm with Lindsay in that I think pretty much all of these creatures are fascinating in how they've evolved to adapt to such an intensely harsh environment. Yeah, I wouldn't like to come face to face with them down in the ocean, but I love learning about them! They're so neat!

For anyone curious about the angler fish mating, first of all, horror warning. Secondly, the male angler fish are much smaller and lack any of the attributes that help their female counterparts hunt (light, powerful jaw, sheer size ect. ). So their only chance at survival is finding a female. Once they do, they give her a hickey and just don't let go. Somehow, rather than destroying the invader, the females immune system accepts the male into her body. After this, the males jaw melts and he becomes completely merged with the females body, he then gradually starts to shrivel up in order to remove all non essential organs. Eventually, he is fully integrated into the female and survives directly from her blood flow, like any other of her organs. There can also be multiple males attached to a single female. So yeah, male angler fish are essentially just the testicle DLC for the females.

The ocean is like a cute looking indie game. It looks harmless on the surface, but the deeper you go, the more horrifying it becomes.

Also, sea cucumbers can fart their lungs out as silly string and regrow their organs. I’m surprised you didn’t mention the Bobbit Worm

bro the dead by daylight skill check sound at 16:10 literally sent me into a full panic--

As someone with thalassophobia, thank you for confirming that my fear of the deep is completely rational and scientifically justifiable

Somewhere in the afterlife, Steve Irwin is watching Casual Geo and Lindsay work, with a happy tear in his eye and smile on his face going “good on ya, mates”

Thank you! I had constipation and couldn't poop for 60 years, but all i had to do was watch this video and instantly crap myself!

Bro watching the deep sea live cameras for a living is like watching jump scares for a living.

I never get tired of actual marine biologists bullying this animal 😭

I absolutely love casual geographic and Lindsay collaborating, best crossover

Very entertaining. I learned a lot. Especially about myself, if I go near a big body of water I planned to wear chainmail and a sport a blade like a medieval knight

When I was a kid, I was really really into deep sea animals (I still am.) I actually recognized a lot of these critters, thank you for making a video about them! I think this is the first time I’ve ever seen someone talk about the praya dubia on RU-vid. It’s so eerie but cool! IIRC, their hunting strategy is basically acting like a sideways jellyfish - they take advantage of their long length by deploying a curtain of stingers below them.

"And the biggest predator that isn't a disgraced former youtuber.." this has to be the best line in this video lmao

This crossover makes the most sense, now we just need one with Lindsay and tier zoo and we have the holy trinity of zoology

I saw the collab name and got so excited because I first found your videos, and then found Lidnesey’s videos while trying to find some zoology stuff to study whilst studying simultaneously for a chemistry exam that was the day after (kinetics and electrochemistry yaaaayy) And then I see you’ve both collaborated and I am happy :)

Congratulations on Lindsay for being the first instance of anyone saying "die" on this channel! "No-one can hide from my sight" - the stop light fish, probably. I bet it's a Widowmaker main Ahh! "Telescope fish"! Now I finally know what it is! You featured them the last time you met up and never said a word!

What's even more upsetting about humboldts is that they're just as clever as many other cephalopods. A humboldt squid once tried to physically pry the mask off a diver in order to drown him.

I can’t stress enough two things: 1. You two collabing is always an absolute gem 2. You giving spider warnings saves my life every time

Great video, really enjoyed seeing and listening to you showing everything. I think listening to you and David Attenborough about the ocean or animals in general is so enjoyable to me 😊👏

Absolutely love you and Lindsay scaring us with the deep ocean, was really great to see you guys sort of going back and forth

A bit further explanation on the Anglerfish reproduction: All the ones seen in the images are females and the males are much smaller. They fuse with the much larger females and eventually degrade to the point where they are essentially just organs for the female. They can also have multiple males attached at a time. Edit: Ma look! My first ever comment is famous!

the irony is that looking scary often enough means harmless in nature, while a lot of cute or pretty often turns out to be mass mudering a-holes.

I really appriciate your spider warnings. It is not that bad for me but it really helps when I can prepare myself. Also thanks for this video, it is amazing what animals are living down there. And the little octopus at the end is just supercute, I dont know he reminds me of a little doggy in the sand 😂

First video I've seen from you and very entertaining! Thanks for the spider warning too!

A close friend of mine was an ex Navy diver. He told me that him and his fellow divers always hated night dives. The ocean looks like a vast infinite pool of black ink. Its a cold, deep, dark abyss. The only thing they ever look forward is ending their dives, resurfacing, hauling onboard the ship, taking off their diving gear and wet suits, and finally heading to the hot shower. The hot shower is probably the only place that feels like it can wash away the night diving experience. Even experienced Navy divers would shudder after coming up after a night dive.

No clickbait, no boring shit, no water-speech, lot's of real footages - Sir, you do need a like!

I really enjoyed your script, so well written. A decent way to spend ones time, well done.

This video is well and truly a master documentary and almost phycological veiw of such creatures especially with the help of Lindsay. Beautiful on both parts

"You're seriously underestimating the ocean's ability to massacre your mental health!" GREAT LINE!

One could legit do an scifi game where aliens are just deep sea critters and majority of people wouldnt know or call that shit fake.

Thank you for the spider warning, but my dumb ass wasn't quick enough to react.

I've just absolutely loved nature and animals since I was a kid, so this kind of informational and comedic content is so awesome dude!

It's crazy how within my lifetime we went from having no footage of giant or colossal squid, to now having footage of divers just casually swimming alongside them.

Casual geographic ☑️ Lindsay Nicole ☑️ Deep sea ☑️ I’m in for a treat

Love your style. These vids are just as informative as they are entertaining. I wish you would add caption with metric system measurements but I am getting better at doing quick calculations in my head so maybe its for the best 😅

This is some of the best narration I've seen on the internet.

It’s pretty crazy how deep sea stuff ain’t even too far off from Subnautica’s intentionally fear-inducing designs

Casual Geographic: I'd rather eat ten pounds of Popeyes biscuits with no drink than go in the deep ocean. Lindsay Nikole: THIS FISH IS MY SON AND I LOVE HIM This collab has a lot of good energy, thank you both so much for creating it. Also, TIL that lizard fish are a real thing, the deep sea is so full of cool stuff wow!

That basket star made my jaw drop! How can something so creepy-looking be alive?

Love the humour in your descriptions so I will subscribe to see more🤭😘

14:58 Casual Geographic: I don’t know who would waste their oxygen trying to defend this creature. Lindsay: *He is my son.*

Nothing is more Lovecraftian than the deep sea itself.

Very insightful and informative, Great video 👍👍

Man I love the ocean. All these critters are so cool looking. This vid is giving me the motivation to get through the lab report I have due. The "horrors of the deep" Are exactly what I want to study, they're just so cool and goofy looking.

I think the scariest thing is that all of these creatures live their lives in complete darkness most of the time and imagining being alone in the complete dark, bumping into literally anything and trying to swim up or down and not knowing which direction is the surface.

The sheer shock and joy of catching an oarfish in Animal Crossing is one of the best feelings ever

I just found you and you're all I'm going to be watching for a very long time 🤣 Thank you for the amazing content!

The animal crossing pun, let's be homies, homie! Real shit though, this education be highly entertaining, well done man.

Honestly the fact that Animal Crossing made half the creatures in this video a) obtainable by fishing with a fishing rod or literally diving down into the ocean and b) really cute suddenly has me rethinking why I have them in my aquarium/museum on the island now 😂 my AC avatar has no idea the danger she’s in

I feel oddly proud about already knowing 90% of the creatures featured on this list

This is the type of video i want to watch at 3AM in the morning

I love the fact you used the Deep Dark Galaxy theme in this.

The fact that the biggest squids MIGHT have evolved enormous eyes partly to avoid and flee from sperm whales hunting them is terrifying

So a few things I'd like to add/mention: * Sea cucumber is also a delicacy like the hagfish, and also features pretty prominently in Asian cooking, such as Japanese cuisine. In fact, the exterior of the sea cucumber and the interior are considered separate kinds of food with their own unique dishes in Japan, a bit like the cuts of meat at butcher's. Sea cucumbers can also move great distances by filling their bodies with water and inflating themselves until they are neutrally buoyant, catching the currents and tumbling through the water until they decide they've had enough of the tumbleweed act. Because I guess sea cucumbers just felt they had to tick off all the weird-as-hell boxes. * Pacific sleeper sharks are actually hella scary for more than just their presence on volcano stages. The longest ever recorded was 14 feet long, but some scientists think they could grow up to lengths of upwards of 23 feet long, which would put them in the same length ball park as the great white. They are also extremely stealthy, capable of gliding through the water without much in the way of body movement, making them absurdly quiet. They mostly subsist on crustaceans and octopi, using suction to swallow their prey whole in one go, but have also been known to eat harbor porpoises and might also prey on juvenile sea lions. So, y'know, just imagine what this thing is up to, ninja-voring victims whose only idea of the sleeper shark's presence is suddenly flying into a 14-foot long shadow's jaws, then add that they aren't confined to the deep ocean like most of the rest of these guys and do hunt for prey at or near the surface. Oh, and pictures of them are often used for "images of deep sea Megalodon" hoaxes, so y'know, if that gives you any further idea as to how terrifying these things are. * The stoplight loosejaw is not only unique in that it uses red light to hunt prey, but in order to see that red light, it processes a derivative of chlorophyll in its eyes, making it the only vertebrate animal known that is capable of processing chlorophyll in its body. The chlorophyll derivative acts as an enhancing photosensitizer, allowing it to absorb long wavelength light that lets it perceive the color red. It does not produce this chlorophyll naturally, however, and is believed to harvest it from the copepods it preys on who use it to get that red coloration. Basically, they turn their prey's camouflage on them by stealing what makes it possible and using it to see even more copepods. Sort of a weird version of 'you are what you eat', I guess.

“Detecting multiple leviathan class creatures in the region. Are you sure that whatever you’re doing is worth it?”

The more I watched this video the more my appetite considerably decreased- I had to put down my food after the hagfish and damn I'm glad I did bc I cannot see sea cucumbers the same now 😩 that being said I love your videos! I can watch them all day long and not get bored once

Until recently, it was thought the Magnapinna/Big Fin squid's tentacles worked similarly to a jellyfish's, that they just dangled until something touched them, which was then reeled up. Then, one was filmed going after a flashing infrared lure (which mimics biolumenescent prey items) mounted on a submersible, and it was discovered the tentacles are in fact like normal squid tentacles, which is to say, prehensile. In the video, they *SHOOT* into frame like snakes striking, grasping the lure the way you would expect ANY squid to grab its food, except, you couldn't see the rest of the squid immediately, just the tentacles emerging from the darkness like blind demon eels. It is DEEPLY disturbing footage. If you're a squishy protein source floating about in the stygian, you might not ever see your killer before it has already caught you.

I can't help being impressed at how Lindsay turns "ocean" into a spondee and "crustacean" into a molossus. Amazing.

That clip of the frill shark swimming towards the camera freaked me out more than it should've

man this is why i subbed to this channel!

“Many say that this is a face only a mother could love , well then maybe he is my son.” Is the quote I am going to use for the rest of my life

Why does Lindsey look so proud of the deep sea telescope fish, like a proud father at their kids baseball game

So informative and yet so entertaining! I can't stop laughing! this is how I like to learn things.

The fact that he and Lindsay even collaborated in the first place makes me MASSIVELY happy to be alive

I remember hearing a story about a diver that got attacked by a group of squid. He thought it was harmless at first but one of them latched onto his mask while the rest swarmed him and started dragging him down. I remember him surviving (he retold the story in an interview) I just don't remember how or who he is. Needless to say it adds to my internal horror debate of which is worse: being eaten alive by a giant thing or by multiple small things?

Omg... that photo of the deep sea telescope fish is so goofy, I love it!!

To me giant isopods are essentially really big roly polies, I already love them.... so I think I'd adore time with an isopod.

"...we seem to have a habit of constantly trying to eat all the things Nature went out of its way to tell us not to." This line made me actually choke on my laughter.

I like how each thumbnail is just getting progressively more disturbing. I hope this continues.

I love deep sea squid research. Cephalopods in general are amazing

It doesn’t help that whenever you’re in the ocean and you look down and stare into the bottomless black, you can’t help but imagine what could REALLY be lurking down there especially since we only explored 5% of our oceans

We forgot to mention the Giant Squid’s arguably more terrifying cousin, the Colossal Squid. We’ve only ever found one example. It has shorter tentacles than the Giant Squid, but it’s got a much heavier, much denser and far larger bell, assumed to be for the purpose of tanking in combat. And the one we found was a juvenile, so we don’t actually know what an adult Colossal Squid looks like, or how much bigger it is than a juvie.

Let’s face it, there was no way this collab would’ve been complete without mentioning the telescopefish

oh ive LOVED goblin sharks since ive heard of them when iw as a kid omg! i thought it was so cool to find out they ejected their jaws! ive also really fallen in love with magnapinna, kapanese spider crabs, and giant isopods in more recent years :)

I know this is an older video but I just wanna say thank you for putting up the spider warning. I have CRIPPLING arachnophobia so the warning helped me shield my eyes before I saw it on screen.

A couple of my teachers have been playing Casual Geographic videos for history and science. He’s very clear, and accurate with his information, but something about the way he talks makes him very entertaining to listen to, therefore making everything he says more memorable. Great channel.

As a retired Ship’s Captain that ran supply ships for the oil and gas industry in the Gulf of Mexico, I can promise you that this only touches on just a few of the amazing things that I’ve seen out at sea. Once you get off the Continental Shelf, you enter a whole new ocean with the increase in depth. I’ve seen Hammerheads with hammers 6’ or more across the front!! Lots of other things that people don’t realize live in the Gulf. Great video!

You did good. Only thing that Mike in your hand I taught it was a lollypop and was expecting you to put it in your mouth the whole clip. 😂✌️☘️

0:16 Not even twenty seconds in and he calls out one of the stupidest and most common nature conspiracies. I respect this man deeply.

The deep sea has to be my favourite nightmare on this planet

Here from a video of an expert reacting to your video but they kept talking over your jokes, so i wanted to hear your video for myself!

Casual Geographics chaotic vibes and Lindsay’s more calm but still chaotic vibes match perfectly

For anyone wondering about anglerfish mating, I’ll break it down; the fish you recognize as anglerfish are all female anglerfish. Male anglerfish are tiny and look like minnows or tadpoles. The males are born and swim around until they find an adult female (~100x larger than the male) and bite onto her side. Their jaws lock and the upper half of their tiny minnow bodies, including their brains, dissolve and fuse with the female’s body, leaving only a little tail sticking out of the female. The male’s reproductive organs stay intact, and the female then fertilizes herself with them when conditions are right for making eggs. The males literally only exist to sacrifice themselves to females. They’re like sperm-shaped fish full of fish sperm and not much else.

At this point I wouldn't be surprised if Cthulhu was actually real, and was just hiding in the deep sea. Wouldn't even be the strangest thing down there.

I’m very happy that I’m watching this in the morning

The Barreleye fish defies reality with how odd it is!

Imma be honest, this has just given me the curiosity for the ocean I had as a kid. There’s so much crazy stuff to learn about

17:51 this feels like the equivalent of aliens laughing at you while you’re petrified in fear.

Very articulate and vocally creative my boy. Nice mouth piece

the deep sea lizard fish looks like an aquatic skullcrawler and i love it

"Who would've thought that just putting elbows on a squid would instantly turn him into the spawn of Satan?" I LOLLED at this

I used to be pretty “meh” about the ocean, playing Subnautica cured me of that

As a " non- buoyant individual" I rarely go deep sea diving!!! I'll let someone else do it!! Adore your vocabulary gymnastics!!! Thanks for another great video!!!❤❤😅

I am just more scared to want to swim or even go in the ocean after this video. Holy shit these creatures or really enormous. Love your podcast it’s amazing the things we don’t know about

The best thing about the deep ocean is that you can't accidentally find yourself there. Also, it seems very reasonable to have deep existential dread about the unknown abyss. It is wild tho: mountain above sea level are the happiest places on earth, at least at breathable altitudes, whereas mountain ranges underwater are wildly terrifying.

I gotta say "Many say this is a face only a mother could love, well then maybe he is my son." is probably the best line I've heard like...ever.