It's Slime Time! | Compilation

[Music] slime can be kind of polarizing there are entire youtube channels devoted to it but start talking about snot and all of a sudden people are anti-slime but slime does more important work than you might think this gooey stuff comes in many forms and it helps out animals and bacteria alike you might not realize it but you're even covered in slime right now so first here's olivia to tell you about some of nature's many uses of slime from self-defense to creating bubble wraps when we humans have a big old glob of snot trailing from our noses it can be kind of gross but snot is just our way of getting rid of dust pollen viruses and other nasty things that might get into our noses and in the animal world slimy secretions can take lots of forms and do other really useful things slime doesn't have a strict scientific definition but a lot of it has the same basic chemical ingredients proteins carbohydrates and lots of water in most slime these ingredients are arranged in long flexible polymers called mucins mucins can have different compositions but they're all glycoproteins which are protein chains with sugars sticking out other mucus can involve water loving sugar polymers called glycosaminoglycans or gags and slime is so slimy because of how these polymers are arranged in a solid molecules are more organized and tightly packed while in a liquid molecules are arranged more randomly and move around more slimes are somewhere in between the polymers are lined up but they can glide past each other they're usually non-newtonian fluids so stretching pushing or squishing changes how viscous they are or how easily they flow now if you were to crown the slimiest creature on the planet it would probably be the hagfish its scientific name mixing glutinosa actually comes from greek and latin words for slime and glue hagfish are jawless sea creatures with long bodies flat tails and somewhat terrifying mouths with rows and rows of pseudo teeth they're made from keratin like our hair instead of materials like dentin and enamel like many true teeth they mostly roam around the sea floor scavenging for worms or eating dead fish from the inside out and if a predator tries to slurp one up like a tasty sea noodle the hagfish fights back it spews a bunch of gill-clogging slime by secreting a concentrated mix from around 100 pores along the length of its body the pre-slime mix contains mucin vesicles that burst in the surrounding seawater because of a process called osmosis the concentration of salt in the vesicles is low relative to the seawater so water rushes through the membrane plus the mix also has fine twisted protein fibers that are unique to hagfish slime called skeins they give the slime strength help it stick together and trap a lot of sea water in fact by one group's measurements about 99.996 percent of hagfish slime is seawater so a little protein can go a long way the more a predator struggles the more viscous the hagfish slime becomes making it gag and back away or if the predator keeps attacking it might even suffocate and die and to escape its own mucousy mess a hagfish will tie its body into a knot and physically scrape the slime off on land leopard slugs don't use slime for defense they use a string of it to get busy wrapping around one another while hanging from a tree branch first off slugs attract their mates by secreting chemicals called pheromones into their slime trail once they've found a partner they climb a nearby tree by changing the viscosity of their slime using muscle contractions at rest mucin molecules in the slime are lined up in a solid so the slime basically glues the slug to a surface but when the slug's muscles contract they push on the slime that rearranges the mucin molecules enough so that the slime flows more like a liquid and the slug can crawl along once slugs reach their branch of choice they squeeze out a long string of slime the molecules realign to form a strong semi-solid rope and then they can do their cirque du soleil mating feats it's a lot of effort but at least one researcher thinks that leopard slugs need the help of gravity to extend their penises which inflate to become almost bigger than their bodies and they have matching genitals because most slugs including these ones have both sperm and eggs inside them and can fertilize themselves so this ooze filled ritual helps ensure that when two leopard slugs mate with each other they make a lot of contact and successfully trades sperm so both sets of eggs get fertilized now one of their cousins the violet sea snail also secretes slime from its foot but instead of acrobatic mating the sea snail uses slime to float on the ocean violet sea snails are pelagic meaning they hang out on the ocean's surface and i mean that literally they'll hang upside down from a little raft of bubbles the bubbles are made by splashing its foot and trapping air in a tough mucus which one researcher described as similar to bubble wrap scientists think that a violet sea snail's bubble boat could have evolved from egg sacs that were held together by a string of goo empty ones may have helped with buoyancy so adding more mucus covered air made this floating ability a more permanent thing with its sturdy raft the sea snail can set out in search of food which is mainly soft-bodied stinging hydrazoans like the portuguese mana war somehow it eats them without getting killed by toxins though maybe the sea snail sidles up next to its food while avoiding the stinging parts or somehow neutralizes the stinging cells either way the mucus probably plays a part so even though glue and boric acid slime tutorials are all the rage on youtube nature has been doing some pretty cool slimy stuff all along and now that we've got the obligatory hagfish discussion out of the way we can get into some more extravagantly slimy animals because hagfish can surround themselves in slime but could they build a palace out of it not many animals can construct a home out of their own goo here is how the giant larvacean one-ups the hagfish this is a giant larvation sorry let me zoom in this is a giant larvation the huge structure around it is its home a palace it built for itself out of snot it's a magnificent feat of engineering especially for a small tadpoley looking creature and these mansions make larvaceans a key part of the ocean ecosystem but the weirdest thing is that as alien as they might seem larvaceans are actually among our closest living boneless relatives because of that they can help us understand ourselves a little better larvaceans are tiny compared to their mucous mansions a snot palace can easily be a meter wide in some species while the architect inside is less than 10 centimeters long these structures have to be so big because they act as filters to catch all the little bits of food that rain down from above what scientists call marine snow but while giant snot palace looks and sounds messy there's a complex structure hidden within this was only recently discovered by scientists as these balls of snot are too fragile to be brought up from the depths without damaging them researchers at ambari actually designed a way to scan the houses in their natural environment using lasers attached to a remotely operated vehicle they then used the scans to generate three-dimensional visualizations which one can enter and fly through using a virtual reality headset this revealed that each palace is full of intricate chambers and passageways we don't fully understand how this sophisticated plumbing works but the gist is that the critter inside flaps its tail to move water through multiple layers of filters the outer filter catches anything that's too big for the animal to eat while the inner ones channel ideally sized food into the animal's mouth and those tubes and such mean that this water movement happens without giving away the location of the actual animal to anything prowling the ocean for a meal here's what's really mind-blowing about all this though each massive intricate snot palace may only last for a day or less after that it becomes so clogged that the animal abandons the entire thing but no worries it can whip up a new one in less than an hour it just oozes snot out of some cells on its head region and inflates the chambers like balloons and ta-da instant house figuring out exactly how they pull that off could help us improve our 3d printing skills or speedily build structures underwater or on other worlds but regardless the discarded houses don't go to waste the food-filled snot ball sinks as fast as 800 meters a day so these empty mansions soon become tasty snacks for creatures that hang out in deeper waters and for seafloor scavengers like sea cucumbers they also make larvaceans big players in the global carbon cycle you see every living thing in the ocean is built from carbon that has entered the water as carbon dioxide when those creatures die the carbon in them has the chance to return to the air but sinking larvacean stunt palaces trap this carbon speeding it to the deep instead where it can be locked up for millions of years in fact in some places they might transfer more carbon to the ocean floor than any other kind of plankton and removing carbon from seawater means more co2 from the air can dissolve in so they are doing their part to lower the carbon dioxide of our atmosphere that's not the only way they're helping us out either they've also recently emerged as model organisms that's because like us they are part of a group called chordates so they share a decent amount in common with us especially when it comes to which genes are active early on in life when we also kind of look like tadpoles they also grow fast and have clear bodies all of which makes them useful for studying how genes affect development so these deep sea architects are inspiring engineers and developmental researchers alike and who knows what else we may yet learn from them this is making me feel like i'm not using my snot to its fullest potential although i do think i'd enjoy living in my current home more than one made entirely out of my own snot probably i mean my nose would probably be raw from all the hard work but why leave it all up to my nose some animals like this next one have slime covering their eyes and thanks to this special coating they don't need to blink as much as we do to keep their eyes from getting dry when someone is faking their sadness you've probably heard it said that they are crying crocodile tears and that saying comes from a myth that crocodiles shed tears of fake remorse over what they've eaten but although their remorse part is definitely a myth researchers have shown that crocodiles and their cousins do get watery-eyed over meals they're not crying in the sense that you and i normally think about it but in the process of understanding what they are doing researchers are also learning more about how these animals keep their eyes moist something that may help us develop a treatment for dry eyes in humans scientists investigated this in a 2007 study they didn't use crocodile specifically because crocodiles are extremely aggressive and agile on land instead they looked at their close relatives trained alligators and caimans who have the same facial anatomy these reptiles had been conditioned to eat on land which was important since it wouldn't have been possible to observe any crying or watery eyes if the animals were in the water and their eyes were thus already wet and it turned out there was a lot to see and researchers observed watery eyes as well as frothing and foaming from most of the study animals eyes while they ate now as for why well it's important to know that these weren't strictly tears in the way we normally think about them in other words the glands around their eyes weren't making new liquid instead this was more like tear film getting kind of regurgitated tear film is the liquid that covers our eyes all the time and it usually drains into the tear duct but in these reptiles as they're munching away the exhale coming from their lungs forces their tear film back out of the tear duct and the frothing and bubbling is a reaction caused by substances in the tears such as proteins it's not just that these reptiles get all watery-eyed though their tear film is also way more efficient than ours like humans have to blink 15 times a minute to spread tears across our eyes but caimans can go without blinking for almost two hours what makes these films so much more stable hasn't been fully worked out but a paper published in 2020 shows that it's at least partly caused by what they're made of researchers learned this by studying the crystalline patterns that formed as the film's dried which clued them in as to what was in them in the first place these patterns are created by large quantities of things like proteins electrolytes and mucus all of which are dissolved in the tear film but get left behind as the water evaporates proteins and mucus both help keep the liquid super stable so it's able to cling to the eye for a long time which comes in handy for animals who spend a lot of time in water meanwhile electrolytes may help keep the eye moisturized and protected from inflammation a better understanding of crocodilian tear films will help us understand these animals as a whole and it could give researchers a better understanding of human tears too if they can pin down the exact molecules and mechanisms behind these reptiles extremely stable films that may lead to the development of new treatments for things like dry eyes and humans not to mention tears and how they work in general aren't well understood so learning more about them will help improve researchers overall knowledge which is nothing to cry about we don't usually think of large reptiles as slimy but tear film is pretty helpful for them and they're not the only animals covered in film we humans also have slimy film all over our bodies so even the animals you don't expect to be slimy can be covered in slime from tear film to biofilm up next here's what biofilms are and what they're doing inside of us biofilm also sometimes referred to as slime is a type of bacterial colony that produces a sticky organic glue which anchors the microorganisms to whatever service they fancy and also to each other making them exponentially better slash worse than they would otherwise be it's also the latest addition to my list of things i wish i didn't have to worry about we tend to think of bacteria as freewheeling loners making their way through the world all by themselves and sometimes they are that way those are called planktonic bacteria but scientists are beginning to realize that bacteria actually spend most of their lives as biofilm which makes them way way way better at doing what they do whether it's helping us digest food or killing us with cholera just as living in towns and cities makes us more effective as a species bacteria living together as biofilm allows them to divvy up labor protect each other and share food and that frees up more time and resources to do the stuff like digesting in the killing their secret is the slimy goo that many bacteria secrete made up mostly of complex sugars called polysaccharides along with some proteins to form this sort of infrastructure of these bacterial towns this concoction of chemicals is actually very similar to a substance our own bodies create and that you may be familiar with mucus through this slime different bacteria can share nutrients in water they can also send signaling proteins to let them communicate they can even swap dna to pass along their genes it's like the united freaking nations of germs up in there because this structure makes microorganisms so successful scientists estimate that 60 to 80 of the bacteria that cause human infection actually live as biofilm and because the only thing they need to start a colony is water they pretty much form in every environment on earth from super hot hot springs to the inside of your mouth in fact if you rub your tongue along your teeth right now you can probably feel maybe even taste the most widely known form of biofilm plaque which is actually a biofilm that contains up to 500 different species of bacteria and is the number one cause of periodontal disease other biofilms are responsible for even gnarlier infections like cystic fibrosis legioneers disease and all kinds of chronic ear sinus and skin infections to make matters worse their thick slimy matrix often makes biofilms antibiotic resistant one study found that bacteria and biofilm were a thousand times more resistant to antibiotics than the same bacteria were when they were on their own but the real insidious part is that biofilms periodically shed their individual bacteria which then go off and start their own infections while antibiotics can kill these planktonic bacteria often making everything seem cool for a while the biofilm death star is just hanging out there waiting to release more of its little tie fighters to attack the body again as a result biofilm infected tissue sometimes has to be removed surgically they're that tenacious so i know it's gross and also it's scary so what are scientists doing to protect me and also you but more importantly me from biofilms well for now scientists are finding out more about them and how they work so that they can develop drugs that can break down the slime in order to help the antibiotics work at the bacteria within the film and what are we doing here at scishow well just know that we made a conscious decision to not show you any actual images or footage of biofilms in the human body so be thankful for that and have a good day well i'm now feeling very conflicted about biofilm yes it can help us digest our food and we need to do that to survive but it can also kill us well there's another slime organism that we shouldn't underestimate and it's known for its relative intelligence slime mold so here's another reason you can't count out the little guys slime mold sounds like something out of a sci-fi movie or maybe what you'd find growing in your shower if you forget to clean it but don't let the gross sounding name put you off these organisms may look like oozing blobs of goo but the more scientists learn about what they're capable of without a brain the more fascinating they are the term slime mold actually refers to more than 900 species found on every continent and despite the name they're not fungi they're actually lumped in with protists these guys have been around for at least 600 million years they're a diverse group of amiibo-like eukaryotic organisms which means they have cells surrounded by membranes and dna tucked inside a nucleus they come in all sorts of shapes and colors there's even one called dog vomit slime mold because it kind of looks like bright yellow puke all slime molds start life as single-celled organisms but when food is scarce they join up to form a bigger mass using chemical signals to find each other plasmodial slime molds fuse together to make one giant cell with a bunch of nuclei floating around inside it which continue to grow and divide in sync and cellular slime molds remain separate cells but just communicate and work together as a big swarm these blobs cruise around in search of things to eat like microbes and when the environment is safe enough slime molds grow tiny mushroom-like sporangia pumping out spores that grow into the next generation of single cells but the weirdest thing about slime molds is that they're actually kind of smart not in quite the same way as animals though when these cells stick together they don't magically grow brain or use tools or anything like that but scientists have found that slime molds can find efficient paths between lumps of food and seem to learn new things about their environment which is pretty impressive for an organism that doesn't have a single neuron one kind of experiment tested their route finding abilities by using maps of countries in a particular plasmodial slime called phizarum polycephalum in a 2010 paper for instance researchers laid out bits of food in a petri dish to mimic towns near tokyo japan first the huge slime mold cells spread out to cover the whole map and figure out where the tasty treats were that food finding strategy seems pretty normal and probably takes a good amount of energy but then the slime mold contracted leaving slimy branches between food lumps to shuttle nutrients back and forth throughout the cell and when they compared this petri dish network to a map of tokyo it was really similar to the way engineers laid out the real subway lines this happens with other maps too physarum blobs find incredibly efficient pathways thanks to chemical signals without complicated computer algorithms or brains actively solving a problem a study from 2008 showed that the same species can learn to anticipate changes in their environment that keep happening at regular intervals like every 30 minutes scientists would suddenly lower the temperature and humidity around a plate with slime mold growing on it and the slime mold would slow down its movement to save energy eventually though the slime mold started to slow down before the change actually hit it had somehow come to expect the change meaning it had some way to sense time passing one researcher suggested it might have to do with the normal pulsing movements of its cell membrane or the fluids inside but there's still a lot we don't understand about how these brainless blobs have a sort of memory another experiment in 2016 showed that phizarum slime molds can even get used to a chemical they don't like over time such as caffeine this is called habituation and is considered to be a kind of learning and when these habituated slime molds fuse with a buddy they can share things they've learned so the bigger new blob behaves just like the habituated one even with all these experiments scientists still aren't sure how they do any of this something biochemical is going on to store information without the help of neurons and doing more research to understand them could teach us more about all life on earth life has existed on our planet for more than three billion years but we think brains have only been around for a sixth of that time most organisms on earth are still brainless and slime molds show how even single-celled living things can navigate complex environments and mess with our ideas about intelligence they could also offer some insight into how the first multicellular organisms formed since they start out as single cells before glomming together so next time you stumble across a smear of yellow goo on a rotting log know that it's not just a gross blob it's a slime mold with a lot of chemical secrets now slime mold is much more impressive than we thought it would be but it's still no match for one of the most notoriously smart animals in the world it's an animal that can make slime blobs as big as itself almost instantaneously i'm talking about the octopus and it's incredible mucousy ink if you've never been inked by an octopus before you might be surprised to find that it's pretty much made of snot so to start and end with slimy sea creatures here's michael to tell you all about octopus ink one of the hallmark moves of octopuses and their cephalopod relatives is that they can squirt ink when they feel threatened typically we think of this ink as an underwater smokescreen and it can be used that way but cephalopods have had the ability to ink for at least 300 million years and in that time they've gotten pretty creative with it we're talking toxic clouds mucousy decoys and even a dazzling display of underwater pyrotechnics trust me cephalopod ink is so much cooler than you ever realized it seems like inking evolved primarily as a way of avoiding getting eaten early cephalopods all had external hard shells to protect their soft bodies but as time progressed they lost or internalized those shells and researchers believe that as that happened the ink sac emerged as another form of defense this theory tracks seeing as nautiloids the only cephalopods around today that have a protective shell can't ink plus anyone who's seen a big old cloud of ink in the water knows it works super well as a smoke screen but not all cephalopod inks are the same you see what we call ink is a mixture made by two separate glands the ink gland and the funnel organ the ink gland is responsible for the actual color you see that black brown hue courtesy of the pigment melanin this gland is an offshoot of the cephalopods digestive tract so you could say these creatures are all technically pooping ink meanwhile the funnel organ is located in the siphon the tube-like organ that cephalopods use to expel water waste and ink it makes mucus which combines with the ink glands pigments before they're released into the water while the melanin encephalopod ink hasn't changed in millions of years there are lots of other components that do vary depending on species like toxins and amino acids and these can give the ink different properties for instance blue-ringed octopus ink contains tetrodotoxin the same deadly paralytic found in the animal's venom researchers think its presence in ink might slow or deter potential predators giving these small octopuses even more opportunity to escape similarly some squids have toxins in their ink that disorient predators this seems to buy them a bit more time which can make a huge difference if they have to outrun a fast attacker and those amino acids they're believed to have a phagomimetic role that's fancy biologists speak for making the ink taste like food so predators try to eat it instead of the actual animal though that's not the most elegant way these animals can use their ink as a decoy remember how i said ink is a mixture of mucus and pigment well sometimes cephalopods up the mucus content a ton to make what scientists call pseudomorphs ink clouds that are roughly the same size and shape as the creature who inked them these no joke seem to function as decoys the actual critter turns tentacle and runs leaving an inky shape behind for a predator to attack sometimes they even release several pseudomorphs at once and then hide amongst them which i assume the predator just finds super confusing they can also make slightly less mucusy ink which unfurls in long ropey strands the animals tend to swim next to these instead of away from them which seems counterintuitive but researchers believe they do this because these inky ropes resemble something else perhaps something dangerous like a stinging syphonophore or jellyfish tentacles or just something inedible to the predator like seagrass and in that way the critter is essentially creating a place to hide in open water of course all of what we've talked about so far are variations on the smokescreen idea it turns out ink clouds can do more than just help a cephalopod flee they can also act as visual alarm cues for others in the area that ink cloud is a clear sign that there's danger nearby and scientists think that the ink itself may also serve as a chemical alarm the idea here is that nearby cephalopods could smell or taste that their cousin is in trouble and therefore danger is afoot allowing them to hightail it out of there even if they can't see the cloud this could also explain why deep sea cephalopods still ink even when they live in darkness some eighteen hundred meters down i mean it's not like a big dark cloud or even a fancy fake squid does much good in pitch blackness when a predator can't see them though there is one deep sea squid that's figured out how to use its ink more like its shallow water cousins it's aptly named the fire shooter squid because it emits glowing ink other squid can make light with their bodies but this is the only one known to date which has a light producing organ that empties into their ink sack allowing them to squirt out luminous ink this ink comes out as glowing ropes or something resembling a shower of sparks and is likely used to blind or distract a potential predator so much like the toxic clouds and pseudomorphs made by the shallower kin it gives the squid a head start when fleeing but perhaps what's really incredible is that all of this is just part of the story when it comes to the biology and ecology of cephalopod inks researchers are still working to fully understand all the variations that are out there and how the animals use them one thing's for certain though the evolution of ink and all these creative takes has been key to the success and survival of these smart boneless marine creatures turns out slime is everywhere underwater inside and outside animals and in you and different organisms use it for very different purposes an honorable mention though goes out to the slimiest humans kids so if you know any little slime balls that might be interested in learning more about their own slime you might want to send them to our scishow kids channel to watch this video about boogers thank you for watching this episode of scishow and thank you so much to all of our patrons for making it possible to share free science education videos like this one if you'd like to learn more about becoming a patron and joining our community you can check out patreon.com scishow [Music] you

Channel: SciShow

Views: 107,607

Rating: 4.9095173 out of 5

Keywords: SciShow, science, Hank, Green, education, learn, slime, animal, biology, crocodile, slug, human, plaque, teeth, biofilm, gross

Id: 4T6qazQp_1g

Length: 27min 39sec (1659 seconds)

Published: Sun Oct 03 2021