Giant Antarctic Sea Spiders | SciShow Talk Show

[Music] hello and welcome to the scishow talk show the day on scishow where we talked to some interesting person about some interesting thing today we got art woods associate professor over the university of montana you study little things that are not so little anymore let's just start out tell me what what is it a sea spider it is yeah so what a sea spider is normally I've got a vial yeah so that's a vial of ones that we collected in Washington State out of the San Juan Islands okay and that's the usual size like hanging out in like tidal areas are they under like I'm the continental shelf they're down within sort of scuba diving distance so then you know hundred feet of the surface and they like just to be in soft body stuff hydroids sea anemones other things like that hide away in the algae okay and they hard to see like vegetarians they just chew up to array on smell they're kind of carnivores but they're also scavengers so you know they're eating soft bodied animals that are easy that they can't run away from them okay and I'm looking at this seems like a bunch of dust basically a little tiny thing weed over four or five days and couldn't find any finally my grad student Steve who has much better eyes than I did said you know there they are didn't have the search image and these are like what kind of I I don't want to show you what's on the table yet viewer because it's exciting so hopefully we haven't done that yet these and these are I mean obviously there are through pods of some kind but they're what are they well they're they're technically in the subphylum chilla Sarada so they're they're more related to things like mites and spiders and scorpions and then they are to things like insects but you know they're all arthropods and so they all have the exoskeletons and they're jointed legs but pretty you can tell are they pretty separate from like what I would think of as like a land like a mite or of daddy longlegs or something they are they're very separate they probably shared a common ancestor about five hundred million years ago you know just just so one way we like to think about the relationships is that a sea spider is related to a spider in the same way that a seahorse is related to a horse it's about that distance of relationship so two lizards but that's different yeah for sure I mean I feel like a sea horse and a horse are pretty much not in the same yeah but they're also device right I guess oh yeah yeah yeah they have backbones so yeah I actually could not have told you that a seahorse was a vertebrate for sure they look real I know they're very strange yeah really odd okay they're fish yep yep okay it's all it's all better now you've been studying sea spiders specifically for a while mhm and you are studying the fact that these things that you can hardly see in this little vial here become this thing yeah pretty dancing you know that like looking at it looking at this 3d print to be clear this is not a actual animal it looks like an electron micrograph of a mite or something it doesn't look like this is the thing that actually exists and one note when I her first heard the term sea spider I just assumed that it was like just a crab it's like some kind of like that's what we call a certain kind of grandpa no this is a very different and very weird and very alien looking thing it is yeah and I mean you see the first traces of them in the fossil record 500 million years ago the old ones had longer tails and there seems like this behaves and evolutionary reduction so that little nub right there is that I thought that was I thought that was an artifact of the print no no so and what's really weird about these is they're all leg right this is like a linker in the middle uh-huh that connects up all the legs and so almost all of the body is leg and one of the really weird things is that the organs go down in the legs so there's gonna and the legs their guts go all the way down to the end of each leg tip where's its pothole the butt hole is on that little nub right there okay and so when you say every tiny bug and you say its guts are in its legs yeah I mean like like food goes down into the leg and then comes back out the leg yeah it goes down in the leg and it gets digested down in there there's a lot of peristalsis and the can get kind of shuttled back up here and there yeah yeah those waves that go down the gut right yeah like the muscular gut is pushing food directly and then you're in a in the legs that's where the absorption of the food happens well no one's really studied that so we don't well we ate its guts usually why we put food into more surface area so here's a crazy thing about their guts and their legs we discovered that they use their guts to circulate the fluids in their body because they have tiny little hearts in the middle mm-hmm and the hearts can't do it they're just too weak and so they're using their guts as a heart basically to move stuff around in their bodies okay sure sure we're done I mean yes that's yeah that's on the list of the weird things it is though it is among the weird things apparently also they have gonads in their legs they do yeah where is the gonads is all is that all is if there's like a cloaca situation where sort of all happening in that tail there are little holes in their legs called gonna pores and when they mate they have to line up they're gonna pores and it's you can imagine our crazy complicated mating is but that many legs try to get them all lined up I love the word going up or yeah it's like somebody was like listen it's like a poor but it's for reproduction it's where the sperm in the eggs come out it goes or I've never knew that gonna pores were a thing is that a thing in other trip to lizards it is and there are other marine invertebrates that have gone up or is this sort of a general word for you know the hole that the sperm in the eggs come off right but it's in the legs in these guys it is yeah not in everything so crazy isn't it yes super crazy and it's sort of it may be a little bit convenient that are there are some giant sea spiders because that would be very difficult to figure out in these tiny things and maybe they're different yeah I don't have so we do a lot of physiology and biomechanics in this project and it would be impossible to do all these little guys and so we really have to do it on the big ones and you know that's part of the question is how can you be giant like that and what do you have to scale up over evolutionary time in order to be a big big thing like that and still walk around and operate and I'm actually like not not a 3d print here as well yeah oh you're gonna take the lid off sure you can hold it so this one's been preserved in ethanol this is a real Antarctic giant sea spider and and also basically a cocktail yeah indeed Oh what in the world is that thing there's like a cucumber on it there's a lot of things right so so those are the palps and they use those to touch their food and position it while they're eating it with a little hole that sits and that's it's where the food yeah that's the boss this is what is called and there's a little set of jaws on the end of that and then the other crazy thing they have see these ones that have the circles on them yeah those are called OVA Jers and they use those circles to groom themselves so they'll run run that down a leg and this guy didn't do a very good job because you can see that he has all this white stuff on him mm-hmm those are those are bryozoans that are growing on his surface and so he's gradually getting covered by my stuff and then the last kind of really weird back to it about these is that the male's use these to carry around eggs so after they mate would have guests on a name yeah the man of the females gives the eggs to the males and then it's his responsibility here I'm not I'm not here yeah you have the over whatever's what do they call overtures overtures yeah I mean the mouth parts are like this is so otherworldly the other the other neat thing is that little stalk right there huh that's the eyes and they have eyes that look in all directions and a little brain in there just right under the eye okay so question yeah how did this basically ocean might become a gigantic and apparently this isn't as big as they get no so the biggest ones we saw really were a little bit bigger than a dinner plate and like when you say like how are you even known these things are around well maybe about a hundred years so so there are records of these from the very first to Antarctica or they would dredge so they're a big scoop basically they're dredging stuff off the bottom and there's descriptions from 1905 and you know we saw these like giant spiders coming out of the dredge so we know that there were giant sea spiders there but there's been almost no work done on them and that's one of the amazing things about going to the Antarctic is it's you know it's basically discovery science you're sort of going into this place where no science has been done yeah and you get to do be the first to do these craziness are you jumping in the water with these guys yeah we so we scuba dived and collected all of our own samples almost everybody on our team was a diver and that that's a whole interesting process and of itself cuz you got to get through the ice yeah you know you're diving around underneath the ice we get the spiders off the bottom there's their super obvious getting ocean spiders yeah put them in a bag I don't like run away real fast no this is a fast spider right I mean you know that's top speed and so we take them back to McMurdo Station which is the National Science Foundation research station that's run by the US and we do our work there do you know why they get so big you know that that's like the 64 million dollar question and the answer is no I don't know even though we've been studying these things for a while and there's about 10 good ideas for why they get giant and we've studied a few of them and you know we still can't say for certain why it is we have we have some some pretty solid ideas about the physiology and and what might allow them to get really big but that's a different question than why I question why right so what's like shoving them toward that city this now looks like food this looks fun you know right a penguin or a seal yeah or something like that like food so one weird thing is we never saw anything predating on these and I agree with you like they're super slow they're really obvious why aren't they getting just scarfed up and we never saw anything bothering them maybe so I saw a lot of mitad lost legs so there's something going on where they they get damage to their legs and they looks like they can shed a leg if it gets infected with something and then they regrow it at subsequent molt so every time we'll see this comes out a little further yeah let me tell you a little bit about what we think is driving or allowing gigantism so allowing it right yeah yeah so one of the major ideas we've been working on is what's called the oxygen hypothesis and that's just like a fancy word a phrase for saying that in in really cold polar waters meant their metabolic rates are really low because they're so cold and that means that they're using oxygen really slowly right oxygens the fuel that's kind of keeping the metabolism going and at the same time in cold water oxygen dissolves really readily and there's a lot of oxygen in Antarctic waters the most oxygen any ocean water anywhere in the world so you got a situation where they're they're using oxygen very slowly but there's a lot of it around then we think that that allows them to evolve really large structures really thick tissues and it's still not a problem to get oxygen into where I sneezed so that's a way of saying that the window is really large into which they can evolve but it doesn't say you know why did that because the line gets pushed pushed way up there yeah when to me it says like maybe there's something that would be filling this niche in a warmer climate that isn't yeah so that that's a great idea and and that's actually a way of expressing an ecological hypothesis so there are very few crabs in Antarctica for whatever reason not even obvious why that should be a but maybe these guys have radiated to fill the ecological niche the crabs fill elsewhere in the world and nothing to do with oxygen it's more of an ecological well it's so it's it but it could be both it could be that it allows for a larger but also there's a pressure toward water exactly and and you know you hear about the sort of like the times in geologic history when there was a lot more oxygen and there were a lot bigger bugs because it was possible to get to oxygenate all this tissue right and you're talking about an animal that can't really even move oxygen around its whole body with its tiny hard and has to do it with its with peristalsis and its guts hmm so it doesn't make some sense yeah I agree is there anything else that's that allows these has allowed these guys to get bigger well I think the ecological ones are the most interesting so the polar environments are really seasonal there's there's a ton of what's called primary production so photosynthesis for about two months in January in February one possibility is that big-sized helps you go through long periods of starvation and so it could be that this sort of super highly seasonal like one pulse of food per year and then ten months of starvation that that selects for large body size that makes some sense yeah and they'd fill up your big chunky legs yeah I've fatten up for a couple of months yeah and just hang out and try to minimize how much energy you're using for the rest of the year doesn't say mob ablai they're using that much energy you know we measured so we measured their metabolic rates that they're Laotian like freezing cold yeah you put a little mask on them and not kidding so they they absorb oxygen across their entire city break them out and take them to the lab yeah first first step so this is a good example draw blood from these guys no there's no blood drawing okay let's say this is a metabolic chamber so so this guy's alive you could put him in here and put the lid on and seal it tight and then we have some sensors that can read how much oxygens in the water and you can just watch the oxygen level go down and from that you say well that's how much oxygen is using right I guess but you can also maybe study that over time without giving them food they could that's tricky because their lives are so slow that we probably have to be down there for years so we would put them in we'd bring them back and put them in what are called seawater tables these are like boxes basically pumping fresh seawater in one time and it goes back out into the member goes down and we wouldn't feed them for a couple of months and maybe it sounds cruel but they're totally fine because their lives are so slow which brings up another question which is how old did these guys get and yeah I would love to know I have no idea and there's I guess is leaking wait am i fifty or a hundred years old absolutely giant ones so you have a podcast yourself so you're making content mm-hmm now big biology it's called yeah and is it about in general like weird organisms that have gotten gigantic for some reason or is it about biology it's just about biology general these ideas to talk to leading biologists around the world about big open questions in biology and you know people that we know we're gonna be interesting on air and have provocative things to say about them about questions that people haven't figured out yeah oh it's been super fun so far we did a really interesting one with Sheila paddock she works on the biomechanics of extremely fast movements hmm stomata pods which are known as mantis shrimps yeah and they have this appendage that they can basically move about as fast as anything in the world gets gets moved and they use it to break open snail shells so as she says it's the fastest thing in the world hitting the slowest thing in the world and there's like a lot of weird biology about that all right well I've heard that we have another invertebrate to meet hang out way that's alive and not sitting in a vat of ethanol perfect and I'd like to meet it now hey Jesse it's like you brought us a normal spider these are outrageous spiders yeah those are she's kind of outrageous I don't know her name is fluffy come here fluffy so not super related to each other but not super not related yeah I mean the big the big move to land yeah it's a pretty big difference especially similary I'm officially sorry eight likes what well it depends these guys have eight and this one has 12 what is unusual yeah freak spider it's a freak spider so like like it looks like too many legs in place of my mind that's really weird and I guess it looks like yeah I know I can handle that I'll just have more guts and gonads yeah no problem how do you I don't know that's so cool so these guys they do not have guts and gonads in their legs oh okay yeah and then they have their heart there's less of cephalothorax there so that's one of the differences between insects and arachnids is that they have the the future heads and and thorax and all their legs come out of the cephalothorax there and then they have the pieces over their mouth and so these guys have turned into things mm-hmm and I actually have this you can see that you can't it's hard to see the fangs under they just like like look like furry little fingers but oh yeah look at that oh I'm not great about rack and mouth parts so do these have their unless they don't really I mean they're in that that same subphylum but they have this very simple mouth so there's like three triangular pieces that come together on the end of the proboscis and it's like a little kind of cutting mechanism and then that proboscis is big because it has a bunch of muscles inside of it and they use that to kind of crush up the food and then suck it back into the gut system where there's no thanks you know there was right at the end okay okay yes same place yeah so totally different ways so these these all hands here are they're just legs they're not look those are palps so they would use those together she also has she has ped up helps and so if you count her legs I have the kids like this and their girl like like spiders have eight legs but then they counts her legs and they're like so these aren't actually considered legs those are pedipalps and she uses those to feel around and help her catch her prey and then the male's they use their pet up helps for Reproductive purposes so they will collect their sperm and hold them into the ends of their pet up helps and then when they come and do the song and dance for the the lady then they've real quick try and stick that they'll use their front legs hold up her front legs and use their pet up helps to deposit the sperm as quickly as they can into a little hole in her their abdomen there and then get out of there as best she can most tarantulas have this fluffy appearance and people think it's for her hair but it's part of their exoskeleton you call it your deck eating bristles and you can see like a like a drier spa top of her abdomen their count work yeah so she would use and she's not missing any in there but that's where she would kick some of her hairs off of her abdomen to protect herself so if you were like she thought you were trying to eat her she would quiver her abdomen and warning and then she would use her back legs and kind of do a rubbing like flicking motion with him and she would kick those here decay ting bristles into the air and it becomes like this almost fine dust of meals are like fiberglass and it goes to nose so bad like immediate reaction to you she was grouchy with me one day I didn't know she was about to molt and I was just holding her and she's like you know you're making me you're making you man ha now leave me alone and she didn't do any abdomen quivering she just kind of went to the second stage and she didn't flick him at me or kick him at me but she just nonchalantly put her back leg up on to her abdomen I was like rub rub and I'm like what do you do would you have an itch I'm like Oh doh here comes the cloud and it was like I could see the sun shining past her and so I could see this cloud coming towards me like putting away oh man I got some up my wrist and some of my neck and then some of my arm there I didn't get it in my for a while almost immediate reaction inching burning and it lasted two weeks worried about isn't the giant fangs I mean he's probably worried about these so these guys came over we did sure sure um so she does detect temperature changes so go ahead put your hands out and she might she'll be all right that kind of cold and so ash man I like that oh when she walks on you you can feel she has these little hooks or their feet a lot of insects have those kind of like little crochet hook yeah two little toes it looks like little furry toes they're kind of cute actually she isn't a great climber she doesn't like to climb she's fairly large and she likes to stay on the ground and so they would find a little crevice somewhere and line there they're a little cave with silk strands there they're webbing and then they would put like tendrils out in front to try and catch the the prayer her little door bells ring in solo Creek it would come by and it touch that and she'd run out there and she'd inject them wait for a little bit she does not spin them up in her little silk web but she would just go ahead and start eating them right there Justin Jackson just so many things crickets like all kinds of insects and small mammals too so she would eat like baby rats and mice yeah yeah amazing yes she has a pretty quick how old is she you know we don't know how she is she started to slow down when she was younger she was much quicker I'd do a little tap on her back leg and she would she would scurry around um but I think she's she's getting pretty old she's molted three times for us do you think she knows you I think they get comfortable with certain interactions certain types of interaction so I don't think she knows me personally but she knows that like this calm flat human and like I can I sit in this perch and I'm not really threatened yeah there's something to me that looks much more sand and I apologize for for putting my values on this but much more advanced about a tarantula vanessi spider sort of an interesting conversation that biologists have sometimes so you're sort of saying that sea spiders are more primitive and that's a way that people sort of apply a value judgment to it and it's it's a funny thing right because these really are their what are called basal arthropods so it's something that looked you know that branched off very early from from Julis roads from arthropods and so it is basal in that sense but it's been evolving for just as long as the lineage that's just didn't need to I mean this is what it came up yeah but yeah these so these guys are related to scorpions too and they think that scorpions were like the the originals and then and then spider formed from that but they both have those specialized mouth parts and the same body structure yeah yeah that that abdomen is so big Eagles around and that's another reason these guys they don't go up into the the trees very much just cuz yeah they are very heavy they're happy and also for agile it's like a big hunk of food if it's like it's not like this it's like chitin that's like a big yeah and the males are gonna be they're gonna be more like a finger with and if she was out there you know not just spoiled she might be a little bit thinner but she's very well-fed look at this and you can see how they molt you can actually see the how the abdomen is just oh just very very fragile so they take all their ducks with them and you can see them just like the exoskeleton in their little tray up there yeah yeah so they they froze back does not have detectable mass it feels like nothing yeah yeah crazy light yeah this molting process is interesting because you see how this one has all the bryozoans on it we think that those things growing on the surface my students Steve Lane has been working on this that that those communities of organisms on the surface interfere with gas exchange and that they may have to molt to get rid of interesting that is it but how do these guys start like today I like have to molt to grow bigger they do yeah like all arthropods they do but that long is kind of mysterious in this group because almost nobody's looked at it we only saw a couple of individuals mole full time we were there it's not totally clear that the when they get to it adulthood whatever that is I think that they keep molting maybe they only have to because it's a very vulnerable process for tarantulas to molt they're gonna flip on their back yeah and the inside skin has to be really soft perfect humidity yeah and if there's a little bit of stress there they're gonna get stuck in their mold and they're gonna die right did you see her come out of these or is it I gotta see her on her back it was for this one yeah I gotta see her back and I'm like oh no she's talking that that's like my first reaction was like oh no she's she's dead she's laying in there upside down but spiders don't die on their pack these days so like immediately I'm like rational and I'm like okay know what's going on and then I sigh wait I tried to wait it happened overnight and so I was like I kept checking on her and then eventually like I slept for a couple hours and then I woke up and there was doing them vulnerable for the next day or two while they harden up and then I they become like oxidized so like the oxygen hardens up their exoskeleton and they can start moving around again but they really don't want to move around because if they do like have to run from a predator or somehow they get in a weird position in their leg moves weird they'll actually harden in a weird position right and then they're handicapped for that whole next year basically right we have insects in the lab that sometimes have a hard time getting out of their molds and and it can kill them yeah you know like they they have to pull out their old tracheal tubes and those tracheal tubes can break off inside of the new ones and then that that stops up the oxygen from getting into their tissues and it's really bad for cancer yeah yeah this does not have no mass I [Music] mean not as heavy as one would expect yeah so she neat yeah so I don't I don't know if I told you what she was she was a Chilean Rose hair tarantula it is not no she's a Chilean rose tarantula okay um and they used to be called Chilean Rose hair tarantula but they moved away from the word hair because it was no hair it was confusing people and so Chilean rose tarantula she's a female and so this is as big as they get and the males are smaller and they they're called rose tarantulas because they have a pink carapace right they're not topless cephalothorax there yeah yeah well thank you fluffy for coming on the show and you know hopefully you weren't freaked out by these many more legged animals Jessi runs animal sanctuary and rescue and has a YouTube channel where you talk about all the cool stuff that you do at youtube.com slash animal in respond Tana and where can we find big biology big biology org awesome it's on iTunes and Google Play so please sign up this is fascinating thank you so much for coming out and for going to Antarctica and dive it into the freezing cold water to life those are gigantic sea spider yeah thanks for having me on it alright thank you for watching thanks for supporting and enjoying scishow [Music]

Channel: SciShow

Views: 290,062

Rating: 4.9084044 out of 5

Keywords: SciShow, science, Hank, Green, education, learn, sea spiders, antarctica, spiders, animal wonders, jessi knudsen castañeda, biology, chelicerata, pycnogondia, arachnida, arachnid, chilean rose tarantula, tarantula

Id: 0XqR2c16PcM

Length: 28min 46sec (1726 seconds)

Published: Wed Aug 01 2018