hello and welcome to our next lecture where we're gonna begin to actually talk about specific phyla of animals so in the last lecture I went over just the very basic animal characteristics so if you if you hadn't gone over that then you might want to go over that first and maybe review a little bit especially a life cycle and characteristics before we move on here and talk about chapter 33 so in 33 your book covers animals that are considered to be what are known as invertebrates right sometimes shortened as inverts and an invertebrate guys it's just an animal that doesn't have a backbone and as you can imagine there's probably and you know that there's millions of species of animals that are invertebrates so there's quite a few animals that make it into this chapter okay so what we're going to be talking about today then are the very first two phyla that fall under the category of invertebrates we're going to be looking at the phylum Porifera and Porifera means poor Bearer so these are gonna be animals like the sponges the second film that we're going to be looking at today is the phylum Cnidaria when you pronounce this term here to see a silence so Cnidaria and these are gonna be things like seein enemies and jellyfish and Hydra and the phylum name comes from the harpoon structure they have in their tentacles so if you ever stung by a jellyfish its from the structure called an Ito site and so that's where the phylum name nidaria comes from okay we're gonna go ahead and start then talking about our sponges and then we'll move over here like I mentioned to the cnidarians but I just want to refer back to this phylogeny that was at the end of the first animal lecture just so we kind of kind of review where we are so over here our ancestral protists was that Kawano site okay those flagellated cells with collars five or six of them stuck together on a stalk they beat their flagella to bring in water currents so that they can trap their food and consume their food that way something very close to that then are going to be our sponges and so our sponges are also from the last lecture referred to as metazoans and those are going to be animals that are next to all of the rest of the animals so this is the only group of animals if you see coming off of this speciation event right here and they have no true tissues so that's why they are not included with the rest of the animals so the sponges have a cellular level of organization that's as complex as they get if we follow down here you see that tissues actually evolve at this note and we're gonna work our way up to the very first group of animals that have true tissues and these are going to be the cnidarians and so these are going to be part of the you metazoan clade true well-developed tissues okay so let's go ahead and start by talking about the the phylum Porifera so in this group here you've got lots of animals that are either fresh or marine okay and think of them as being micro filters they're exceptionally good at filtering out the water that's around them because that's how they're going to feed and so as you can imagine they can give you a quick indication of the overall health of the habitats in which they live because if there's toxins or poisons or any sort of pollutants in the water that they're filtering they're gonna bring those toxins and pollutants inside their cells which will then cause poor growth or kill the this the sponges all together and so sometimes they're quite indicative of the overall health of the either the freshwater body or the ocean in which they live because of their ability to be micro filters okay so they are asymmetrical and so last time I talked about the fact that we have three types of symmetry really asymmetrical as you see here in the screen in front of you other animals are going to be radial in their symmetry or bilateral and this one is asymmetrical because if you look at this there's absolutely no plane of division I can't cut this right here for example down the middle and have the the left side be the same as the right side I can't cut this guy in half this way and half the top bead the same as the bottom okay so they are asymmetrical and they are sedentary and what that means is is that they cannot move they are non motile they have no ability to move they're stuck always in the same spot okay and then once again to finish up this part before we go to the actual body plan here part C in the notes is that they have a cellular level of organization so that means that that each cell can do basically what the entire organism needs they do not come together to make true tissues and we refer to those as being the metazoans okay so the body plan is something that we want to focus on here Oh quite a bit and I'm gonna go through sorry I'm gonna go through the terms and then I'm gonna show you the pathway of water so what I think would work best is to go through the body plan looking at those terms that are there and and then give you the details so let's just go ahead and define so the first term there is epidermis and so you can see the term epidermis is right here and it's pointing to this cell right here and what I want to make sure that you're not gonna confuse this one with as being ectoderm so ectoderm is a tissue right that we see in animals all of the other animals except for this class or this group writer of porphyrins so epidermis just think of this as the outer layer of cells okay outer layer of cells not to be confused with ectoderm and know that these cells here are not forming a tissue of any kind riddled throughout the epidermis are these little openings here called pores so there's one there there's another one there you can see that there's a cross-section of one there and that's gonna be an opening then that's gonna allow water to move then from the ocean or the lake where of the sponges living through the pore and into the inner portion of the sponge now those terms are the eternal here purport should actually be Ostia I don't know why they don't have it there in the notes but I want you to highlight or circle the term Ostia because that is the most correct term then that we use for these guys here that are the openings or pores those are called Ostia the opening here the center of some of the most basic sponges is pretty big it's a wide open space and some not in all but any opening here is called the sponge assault so the sponge whistle is going to be the center of the sponge if it exists okay lighting the sponge as'll are these little collar cells that are similar to the kawano flageolet that we looked at and these are called the Kawano sights the generic name for them is collar cell and so we'll take a peek at one of these in more detail over here in just a minute we have amiibo sites so an amiibo site is not the same thing as an amoeba but amiibo site is site means cell amoeba is describing the movement of these guys and the amiibo sites are going to be these little tiny blue cells and you can see them better up here and there there's another one there and they are cells that are kind of sandwiched in the middle of the two cell layers and what they do is they are totipotent which means that they have multi functions so they are responsible for moving food throughout the body of the sponge they are responsible for making spicules that I'll define later for the sponge they're also even sometimes responsible for making gametes so they have very a very diverse range of functions that they are responsible for but they are not amoeba but amoeba like cells so they have a creepy-crawly movement using those pseudo pods if they need to to move from point A to point B okay spicules so I just mentioned that term spicules are these little Oram kind of yellowy things that kind of look like a mercedes-benz emblem and so you can see that they are kind of sandwiched in the in the center here along with the amoeba sites in many cases there's another one there there's one there there's one there you can see that there's a couple of them that are actually sticking out they're very spiky and what I need you to understand about the spicules the suspicous make up the skeletal framework for the sponges okay they make up the skeletal framework for the sponges and they can be glass like in appearance they can be made out of calcium carbonate which would be more of like a shell if think of like a seashell or something like that but made up a different stuff they can have three points like this one here for the Mercedes boom emblem and they can have more many more points than that but just the generic definition of a Yule is that that is the structure that makes up the skeletal structure of a sponge okay mezzo Hill so the mezzo Hill is think of it as a glue and so you can see the line right here is pointing to like this brown stuff so on the outside right here I have the epidermis right so not a tissue but just the layers on the outside of the sponge on the inside I have another layer of cells the Kawano sites and gluing those two cell layers together is this stuff called the mezzo Hill so if I come up here it's this brown substance there it's then attaching the epidermal cells to the colano sites they're embedded within or sandwich inside of the meso Hill will be spicules if present and amoeba sites if present and what this does then is it allows the sponge to be simply two cell layers thick epidermal and their epidermis cells I should say and Kawano sites glued together with the with the mezzo he'll allowing them all of the cells that make up the epidermis to be in contact with water at all times and also allowing then the Kawano sites to always be in contact with water at all times all of these other structures the mezzo hail the spicules and the amoeba sites are not necessarily going to be exposed to water at all times but for feeding and to prevent drawing out of the sponge it is imperative that you have water always touching the epidermis and water always here at the Kawano sites and then finally the last term that's in your notes there under Part D is going to be the oscul 'm and the Austell 'm is going to be this opening that's up here at the top and the oscul 'm in this picture is very apparent and very obvious but it will not be always in the sponges especially as they get more complex than the one that they've shown here and I can show you then the oscul 'm it would be that opening right over here in this picture and then there's another opening right over there a nap in that area of that sponge okay so what you need to know now that we kind of have an idea of what the terms are is we have to follow the pathway of water so we can kind of talk about what all these things do so for the pathway of water or the flow of water water's gonna obviously going to come in and it's going to enter through those Ostia and it's gonna make its way into the sponges soul and what's gonna happen then is when the water makes its way in the flagella on the collar cells are going to beat in unison so if I take a peek at one of those collar cells over here then I can explain how the sponge feeds so once the water comes in through the Ostia into the spongy sole the flagella of the quano site starts to beat it's gonna bring water over to the collar portion of the cell and now there's mucus that's gonna be secreted by this collar portion of the kawano site and what that mucus is gonna do is it's gonna trap the food particles in the water so all these little red dots here okay they are food particles debris smaller animals smaller protests bacteria whatever it is that they eat they're gonna trap at the collar portion of their cell they're then going to move the food then in through phagocytosis which is a term that you have seen before right into then this head region of the Kawano site and those food particles then will be digested by food vacuoles very similar to what happened in amoebas once in a while and they're showing it here some of that food that's trapped by the Kawano site will be moved then and taken up by the amiibo site also via phagocytosis and the amoeba site needs to have some food for itself so that it can survive and then the other thing that it will do with any extra food is think about it if you maybe this amoeba site over here and there's no amoeba sites over here and there's no pores how are these cells right here going to be fed so the amiibo site then can use their their cytoplasmic streaming okay to make pseudopods to kind of migrate through the epidural cells for example to deliver food me to that area of the sponge and so that's what the the book wants you to know is happening right here and that's why they've shown them to me but say right next to the kawano site so once the water comes in food is trapped then the sponge doesn't need the water anymore so then the water is just going to exit from the sponge whistle and out through the Ospital so if I ask you what's the pathway of water through a sponge it's as simple as this guys it's gonna come in through the Ostia it's going to enter the sponges so it's gonna exit out through the oscul 'im if I ask you why it does that well it's doing that for gas exchange to bring oxygen to the cells so they can have that for sale you the respiration and then exchange for that they're going to give off co2 just like you do okay so that simple diffusion that's gonna happen here in these cells and here in these cells so that's one reason why we have to have a flow of water constantly through the sponges and the second is for feeding so that they can trap their food they are filter feeders they're gonna trap their food bring it in and then have those food particles digested once again within those food vacuoles okay here is a picture of just a variety of different types of spicules before I move on to the three different body forms that we see in the phylum Porifera this is going to be very similar to a picture that you're gonna be asked to draw in your lab where you've got the three-prong mercedes-benz emblem type of structure and this is going to be aspic you'll that is made out of silica same thing that those diatoms in the group of the protest those single-celled algae what they're made up of is so they're pretty they're pretty heavy they're pretty deaths last like in appearance as you can see they're very opaque as the light hits them under the scope over here they're showing so this for example would be something similar to this guy over here but as you can see there's a whole variety of different types of spicules that are found then within a within each of the different classes and then each of the different species of spicules but nevertheless regardless of what they look like they all have the same function and that function is to be as a skeletal supportive structure for for the sponge okay in your notes for e we have three body forms ask annoyed sigh conoid and luke annoyed so your next slide here is going to show those ask annoyed sigh conoid and luke annoyed and this is from your textbook and what they've done so that they didn't have to give all the details they've trying to just color coat if you will the different layers so remember they're not tissues but the different cell layers so Kawano sites are going to be the red the red and the red the mezzo he'll remember is the glue light structure that's going to attach the Kawano sites and the the epidermal cells together which they're using a different term here the yellow I just want you you could just ignore that completely and I want you to know that then as epidermis okay and so that's gonna be the outside so epidermis mezzo he'll cry no sites and then they're just showing the flow of water obviously the flow of water is always going to leave through the oscul 'm and you can see depending on the different body plan for the sponge that oscul 'm can be quite significant or much smaller you can see that the sponge as'll right the center of the sponge can be very obvious as it is there and there but not so much over here it's broken up into smaller parts and I'll explain why that's advantageous here in just a second okay so let's go ahead and start with this guy here that a scan way so that a scanner way this is going to be the simplest of the sponge body plans this is the very first sponge body plan that evolved and literally you're just going to have the water that's going to come in through the us yet to the sponge tool and out through the oscul oh there's no other path for the water to go except for in and then straight out so very very simple after the ask Android body plan then a little bit of evolution has occurred and we make our way then to what's called the psycho annoyed body plan and this one is a little bit more complex than asked then the ask annoyed so you can see that I've got a little bit of the mezzo Hale broken up along with the Kawano sites here and so it's kind of like a little bit of a maze for the water to come in so when the water comes in through the Ostia still it might make a turn there there it might follow this path before it actually gets to the sponges soul and then out through the oscul oh and the reason why it's this way here why this is advantageous is that has increased surface area and so there's going to be a lot more feeding because there's going to be way more Kawano sites available now to trap the the food that's coming in the water as the water makes its way in maze in through a maze before it enters the sponge tool and then out of the sponge finally the most complex of the three sponge body types is this guy here the Luke annoyed and the Luke annoyed is probably a sponge body plan that you're probably most familiar with if you've ever bought a loofah a sponge a loofah or if you've ever bought sponges that at Home Depot sometimes people use those like for faux painting and things like that that is the Luke annoyed body plan okay so you can see that there's no obvious sponges Sol really the oscul amiss quite reduced but there is a lot more channeling in each of those channels than are going to be lined with kalenna site so it's imagine taking this area here the sponges tool and then just breaking it up into smaller pieces and so what that does then is well as the water comes in it's going to go through that channel through that channel through that channel maybe through that channel here follow that maze and then finally up out through the very small sponge as'll and then out through the oscul 'im and that's just gonna increase surface area even more than the psyche annoyed body plan allowing them for greater amounts of filter feeding and also gas exchange one of the things that the lab is going to ask you to do is to go through and draw a name these different body plans for the sponges and so if you just do a very basic drawing just so you get the gist of what's happening and how they are different from one another and then again ignore the this term here and just replace it please with epidermis okay now as far as reproduction is concerned it's pretty simple in the sponges so there is asexual reproduction here so this is one of the animals that can bud and make clones of itself and this is the the illustration that you have here from study and score comm so you've got sponge sponge and then a little clone growing off over here to the right it's going to mature a little bit more and then it's basically going to imaginate here so much so you can see it continuing here that it will eventually pinch off from the parent it's picked up by the water currents and then it just helpfully lands right side up and will attach itself to a substrate where it will then continue growth right and and forever live in that one spot and resume filter feeding gas exchange growth and reproduction on its own so that is called budding and that's literally just making a clone of itself so can't get any simpler than that okay for sexual reproduction these guys are going to be hermaphroditic and they're going to use structures that are called a plan EULA so if you look at a spur I'm sorry no sperm if you look at a sponge rather you've got the adult and they've got quotes your male and then the adult again in quotes female so what the term hermaphroditic means I need to explain that for this slide here to make sense is that the sperm I'm sorry I keep saying that the sponge makes both sperm and egg cells okay it has the capability then to make either or because if you remember it's the amiibo sites that are responsible for making gametes and so if the environment is telling the sponge that it needs to make sperm cells today then it's going to be the quote-unquote male but the next week then it might be told based on environmental cue like hey you need to make egg cells and so it then could become the next week the adult female if you will okay so if we look at this you've got an adult male you've got the adult female and you've got a flagel ated sperm right and that's gonna look very different than the egg cell so remember all so reproduction and animals that sexual is a lot and that's the perfect definition of it right there and the amoeba sites have made sperm cells and the sperm cells that are gonna exit through the oskol 'm with the water current and hopefully you have a neighboring sponge of the same species somewhere in close proximity and this picture doesn't isn't really correct this the sperm cells right they're gonna be brought in through the Ostia within the water currents into the mezzo hill where hopefully they will come into contact with them a proper egg fertilize the egg that's in the mezzo hill as I go is formed a zygote goes through cleavage so if you go back to embryology that's all that I am talking about here and it goes through and eventually then we'll make a larval stage that is free swimming so this is the only stage of the sponge lifecycle that can move that is motile and that will exit then out of the oscul 'im it'll swim just a matter of hours in most cases it will find a hospitable environment it will settle down it will continue to go through metamorphosis and cleavage and it will become a young sponge and that young sponge will reproduce itself a sexually and also sexually depending on what the environment is saying now people will go down and they'll harvest sponges for sale and like with a lot of other things you know we should be concerned with over harvesting or over hunting of animals but you don't have to worry about that with the sponges because if you go and you cut off just a part of it what that's going to do is going to cause then regeneration to occur and the sponges actually grow more of themselves asexually so it actually prompts them to grow and when you cut off parts of the original sponge so it really would be hard to over harvest sponges okay this right here this free swimming larval stage is what is called a plan EULA so the plan EULA next to the term hermaphroditic for F number two under sexual reproduction just realize that this is called a plan yellow larvae and what that means that this is free swimming larval stage and then one last thing that I want to point out just to kind of tie back into one of our previous lectures is if I had a sponge here that was of species a let's say and another sponge over here that was a species F theoretically they should not be able to mate with one another okay and there would be a pre-psychotic isolating mechanism in place to prevent the hybridization and if you remember what that would call what that one is called that is called gametic isolation so even though the sperm can come into the body of the sponge they can come close together but if they're not genetically compatible then due to comedic isolation there would never be fertilization that takes place to make a hybrid so this fertilization to get us the plan yellow larval stage is only going to happen or should only happen when you have sponges that are of the same species okay so to finish up here with this group we are going to talk about three different classes calque area demo spongy a and hex actin Alita try to say that one ten times right those are the three classes that your lab is going to ask you to identify so the calcareous sponges are going to be these guys right here and they are the simplest body types most of the time they're spicules are made out of calcium carbonate which again would be that that hard stuff since like in a shell from a from an animal in the ocean so very strong not glass-like but really strong structure there okay they tend to the sponges in this group calc area tend to be very small sometimes even microscopic and they can either have the ask annoyed or or the psyche annoyed body plan so not the the most complex to look annoyed but the first and the in the middle the demo is spongy egg this group here as you can see the spicules then are made of silica and so like with the diatoms it's a glass-like and appearance and they're they tend to be pretty heavy the spicules here are sometimes mixed with this stuff called sponging that is very spongy hence the term sponge okay most of the body plan that we're gonna see here is going to be very complex that's gonna be the Luke annoyed body plan so even though this tubular structure kind of looks like this one here remember what you have to consider is what the canals look like so does the water just go in out or are there twists and turns and amazed that the water has to go through in order to get to the spongy soil and then out through the oscul 'im and then finally this guy here the heck's actin Aleta Kay spicules with six rays so double the three that I showed you earlier also made out of the silica again and they can be that the psyche annoyed or the Luke annoyed body type so there's not a lot of rhyme or reason here because it's a lot of gray area but I just wanted to point out the names of the three different classes of sponges that again you'll be able to to go through with the lab intro and I and I hope that that'll make it a little bit easier for you to understand okay the last thing that I wanted you here for this violin before I move on to the phylum Cnidaria is to just kind of give you a preview and an intro this is what I would show if we were in class here so one of the things that the lab is going to ask you to do is to look at the genus of sponges called grant yet and in cross-section so if you took one of those sponges and you crossed it in half what does it look like looking at it from the top down and then also what do the spicules of the grant 'ya genus look like so let's go with the cross-section first so this area right here right so I take a tube it would be like taking this guy and crossing it this way and then looking at it from the top down so I'm gonna have a large open area here that is going to be the spongy sole we're gonna have the Ostia there's an ostium there there's an ostium there right so these are all the epidural cells that are there so the water is gonna come in this way and into the spongy sole you're going to have a layer of colano sites here here here kind of just where it's a little bit darker and so this is obviously hopefully you're saying that this is the psyche annoyed body plan so when the water comes in its got to kind of make its way through a couple of little passes before it actually reaches the sponge of salt and then here's the mezzo Hale that's going to attach then the Kawano sights then to the epidermal epidural layer that's on the outside okay layer of cells okay the spicules for this particular sponge look like this so they're they're your typical mercedes-benz emblem with the three rays and they are glass like in appearance and that is exactly what they would look like underneath the microscope with your slides the other specimen that the lab is going to ask you to look at this is going to be an ask annoyed body plan so this is the simplest one this is called Lucas Alinea it's a very very small sponge sometimes only I don't know half of an inch tall they have spicules that look like that but they're not made of silica they are actually made of the calcium carbonate but because this is going to be the ESCO annoyed body plan you're gonna just have the water move in through the Ostia into the major sponge assault and then out through the Ostia so just one pass in and out okay the next group that we have in store then for the very beginning of this chapter are the cnidarians so phylum Cnidaria and you're going to have things like this that I'm sure you're familiar with right that's just gonna be your true jellyfish you're gonna have things that look like this these are going to be your sein enemies and then you're gonna have different types of coral and the coral isn't the animal the animal is inside of the coral in the coral coral is there because the animal actually secreted calcium carbonate that term should be familiar with you to you because that's what some of the spicules are made up of but the actual coral is the house that the the animal is secreting for itself okay so for your cnidarians before we go through the body plan there which is actually pretty simple they are mostly marine they have Oh symmetry so if I tell you that they have radial symmetry you should automatically know that they have tissues and that they have two layers of tissues so these are going to be bilateral I'm sorry um not bilateral but diplo blastic my bad Diplo blastic so they have ectoderm and they have endoderm okay because they have true tissues then they are more complex than the sponges and they are the first group of animals that make up what are called the you metazoans and those are your true animal or not your true animals but your animals with true tissues I should say okay let's look at e number two e let's look at the body plan here so you're going to see here when the slide comes up in just a second that there are two body plans polyp and then there's what is called Medusa so figure 33.5 illustrates each of these so if I look over here on the Left this is going to be my polyp body plan and the polyp body plan is SAS eye which means that it doesn't really move and if it does move it's very limited in its movement and that's one of the things that you should already know because of the fact that they have radial symmetry we said that movement is very limited they can sense their entire environment but they can't move very effectively and so what you've got going on then is you've got the bottom here um this is called the pedal disk so ped like your foot right pedal disk kind of like a pedal and that's gonna attach to the substrate and you're going to have then the epidermis but this time the epidermis is actually ectoderm tissue so not the same as epidermis that we see in sponges that's your blue color this is color coded to be consistent with it the tissue layer when we were talking about gastrulation inside this is going to be the yellow gastrodermis tissue that has matured from the endoderm okay so the epidermis came from ectoderm the gastrodermis came from endo germ and these are both examples of true tissues the mouth this is the oral side is up here sir by several tentacles there is a single opening you see that the label there says mouth slash eNOS so this is going to be an animal that I'm going to say has an incomplete digestive tract the death the digestive tract remember comes from the ark enter on and that's going to be this area here called the gastrovascular cavity so when these guys feed they're going to catch their prey with their tentacles they're gonna bring the food in through the mouth the food's gonna enter the gastrovascular cavity it will be digested what can be absorbed will be absorbed but then there's gonna be waste of course right you bring stuff in you've got to give stuff off or get rid of stuff and so that waste then will go up out through the same opening called the anus and so that makes this an incomplete digestive tract because there's only one opening okay there's mezzo glia and the mess of glia is kind of like the mezzo Hale in our sponges where this is going to be kind of like a glue it's like a really thick jelly hence jellyfish and what the mythically is going to do it's going to be a slippery jelly like layer between then the epidermis and the gastrodermis because when these guys move if I go over here to explain this I could do it a little bit better with the Medusa body plan this is your jellyfish with the bell or the Medusa with the tentacles hanging down but this guy moves it kind of like flutters through the water it contracts then a little bit of the gastric dermis and the epidermis and if these two layers were right on top of one another then just imagine having your hands one hand on the other one and moving them back out maybe right and left or backwards and forwards eventually you're going to have friction and these layers of tissue are so thin that if they were constantly in contact with each other well that they were moving if this is moving in that direction and that's moving in that direction there's gonna be friction was just going to damage the tissues and so what the Meza bleeeh does and you can see them as ugly and parts are really thick like up here and then the mezzo glia over here it's a jelly like substance that allows them the gastrodermis to slip over it independently from the epidermis and so that reduces friction and then that prevents any rupturing or damage to those two types of tissue that are used when the animal is able to actually move okay so the only thing that's different here with the medusa body plan right it has all the same parts the same layers it's just that the mouth / anus is now facing down rather than facing up like it is over here so that changes the term so this is the oral side this is the AB oral site this is the oral side this is the AB oral side so you need to be sure that you're familiar with those terms and the orientations okay so something that's really unique about these guys and again this is why they're referred to as the phylum Cnidaria is because of their tentacles so they are carnivores with tentacles and their tentacles are aligned with these cells called NATO sites that store these structures called the mattis's that are both there in bold is parked g4 number two at the very bottom of page four so let's go ahead and take a peek at what is going on inside of the tentacles here in Figure 33.6 so if I take this would be the polyp body plant right this is the oral side the abnormal site this animal here is actually referred to as a Hydra this is one of the organisms that you'll be working with for the lab but if I were to take a very small part of the tentacle and I were to blow it up and expand it this is what it's going to look like so I've got then the cells okay that if you go back for just a second that are making up the epidermal tissue this time not just cells but tissue I have these little kind of like spiky things coming out of it okay and so if we take one of these and we look at it up close so here is the epidermal cell there's the up the other epidermal cells so that would be like that and that right there and then this here in the middle is a second type of cell called a neato site neato site site means cell and if you look at this you can tell that this part right here including the trigger right is a cell because it has a nucleus and the reason why I'm trying to emphasize this is because students always get this term neo site mixed up with what's inside the Neto site this guy here called a nomad assist so then a Matt assist is not a cell instead it is a harpoon like structure that is stored inside the Neto site so it's a thread that is coiled inside the Neto site so that if you're swimming along and you brush up against the tentacle of this Hydra for example or a jellyfish you're gonna touch one of those triggers and automatically what's going to happen is when that trigger is is brushed up against even if it's just a slight little touch that pneumatosis is going to eject itself it discharges out of the Neto site and it would look like this so what this picture is trying to show you here is that this would be this organism called Daphnia this is a water flea so the same thing as basically the fleas that your cats and your dogs get except that it's just an aquatic species and this is an animal that this Hydra would eat and so if this little water flea is is swimming around and it touches the trigger then if it's still close enough the nomads assist is gonna harpoon right through the body of that water flea and it's gonna send this thread and this thread is going to have toxins and as you know sometimes those toxins they're just an irritant they sting and they may hurt for 30 minutes or so well other jellyfish especially like the box jellyfish this thread right here can have neurotoxins that could that could kill a large animal including us rather quickly but that's the idea there so let's go through this one more time so here's my tentacle if I look at the tentacle there's gonna be these little triggers that are every couple of cells and those triggers belong to the cell here called the nino site the neato se is strengthened a mat assist which is the thread harpoon life structure that will discharge when something hits the trigger and hopefully for the animal here the Hydra it's able then to harpoon its prey kill the prey let it die and once it stops moving it'll move it down its mouth into the gastrovascular cavity and it's kind of funny because sometimes guys these little Daphnia hair these little water fleas can actually be bigger than the Hydra but they can they can manage to get them down in through the opening of the mouth you can see it because these bodies are normally clear in nature the Daphnia or the water flea will be digested and then remember all of the waste that this little Nigerian in this case a Hydra cannot handle or use if it's just waste it's gonna go right back out through that same opening okay so please please please do not get the term Neto site mixed up with nomad assist the needles sake because it has a term site in it is the cell that stores the harpoon called the nomad assist okay we've got two clades that we are going to be looking at there's more that exists in nature but we don't have examples for all of them so we're just gonna focus on these two groups here we're gonna talk about the Medusa zones and then we're going to talk about the anthozoa pnes so let's go ahead and look at this repair the Medusa xoans first and the first group that I want to look at is the clade Medusa ZOA but I want to look at animals in here that I'll refer to as Hydra zones so now I'm at the top of page five and what I'm looking at here is number one clade Medusa ZOA hydras Owens with dominant polyp they're the called the Hydra sand I have two different speeds onra rather they're under that group okay so this first one is going to be Hydra so this is the name of the genus Hydra so this right here this is the animal okay and they're only usually about maybe a couple of millimeters tall so they're very small so this right here is the equivalent of this right here okay so if I were to ask you what the body plan is right here you should tell me that that's the polyp body plan here's the pineal disk that's going to be the part that kind of like a suction cup almost that will attach itself to the substrate this is going to be the melt slush enos you can see the gastrovascular cavity is here and then here are the tentacles and you can see that the tentacles it almost looks like they have little kind of beads on them but those are each going to be the the Nino sites with the new Madison sword inside of it okay so if we look over at this it's the same thing so there's your base or your penal disc okay here are the tentacles there and there and then there's the mouth but there's a couple of things that I wanted to highlight here so this is showing the mail and the mail well some of these species can be hermaphroditic and some of them are not in this case they are not so this is only going to be a male Hydra and what you can see then are these little bumps and the bumps are always going to be closer to the mouth if it's going to be the spur merarys which are the testes so there's a teste there's a test feed there's a test E and then there's at-st okay if it's a female she's gonna have a much larger bump and that bump is usually gonna be at least Midway or closer down to the bottom now I say this because once in a while if you look at a slide it can be a hermaphroditic Hydra and it will have the testes and then ovaries down here but in this case this picture is showing you single sex Hydra so they do undergo sexual reproduction obviously so this is going to be making sperm cells and this is going to be making egg cells but in addition to sexual reproduction these heydrich commonly will reproduce themselves a sexually and that's what this little guy is here so this is a bud and this is a bud and that's gonna be a second bud so this is not just a really swollen ovary these are actually buds and so they're gonna make very small clones of themselves those buds kind of like with the sponges will pinch off eventually and float down rearrange themselves with your petal just down here and then their tentacle is facing upwards okay that is pretty much what you need to know for the Hydra as far as is the notes here and then also for your lab but another group within the same clade Medusa ZOA the same subgroup hydras Owens is going to be an organism by the name of OB Leah okay and what I want you to notice here is that this let's look at this picture for just a second this is a colonial polyp so with the Hydra it was living on its own and was not a colony that's it right this is it this is it but another type of a hydras Owen in the clade Medusa ZOA like this OB Leah is in fact a colony and so you can see from this picture you've got lots of polyps that are just attached to the stock here so that makes it a colonial Paula so if we take and we look at this that's one thing that you're going to want to make mention up in your notes under OB Leah is that it is a colonial polyp okay and let's look at what's going on here because you've got two different two very different types of polyps so anything that has these tentacles that are coming off of it like here and here in here and then there's some more down here those are all going to be for feeding right because the tentacles have the the Nino sites with the nomad assist to catch the food so those are obviously all going to be used for feeding but you can see that kind of mixed in with all the rest of the polyps there's another pump and you can see this one really good that doesn't have any tentacles and because this one doesn't have any tentacles then this pulp is not for feeding but it's going to be used for reproduction and in this case it's going to be sexual reproduction so what's going to happen then is if I'm talking about this guy right here that particular polyp okay it is going to push out the other stage that's possible in this phylum the Medusa stage so little teeny tiny jellyfish looking structures are going to come out of the reproductive polyp but they are not jellyfish because they are a hydras Owen I'll explain what a jellyfish is and where it belongs in a second but they have that Medusa body plant and those are going to be very short-lived okay they are diploid structures so notice everything in here is diploid now except for the gametes so it's a diploid dominant lifecycle as I mentioned in the previous lecture and the Medusa is going to have gonads that are going to make either egg or sperm so female male as soon as these Medusa stages within this lifecycle make their gametes and release them they die okay they're they're just done they don't grow into anything else they do not survive very long and so what's going to happen then is they're haploid egg that's been made in there via meiosis and the haploid sperms made in the gonads via meiosis come together and again this is going to have to be a comedic isolation to make sure that the the right species are coming together but you're gonna have fertilization so sperm and egg come together and you get a zygote that's now back to the diploid um stage it goes through cleavage it makes the blastula so hopefully this is becoming somewhat familiar to you remember this is your little hollow ball of cells and in this case then it's gonna go through and is going to make a plan yellow larval stage okay it's ciliated which means that it can move it can swim it'll swim for a matter of minutes or hours it will settle down it will continue through cleavage and metamorphosis it will then develop into a mature polyp and this guy right here will be the feeding polyp it's hard to know what this one will be probably another feeding polyp and then interspersed within the feeding pulps once in a while you have the reproductive polyp and so the other thing that I want to point out to you is that the polyp is the dominant stage of the life cycle right that's what all these guys are here the dominant body plan I should say but we do alternate between the polyp body plan and the Medusa body plan but the Medusa body plan is only there once again simply to make gametes within the gonads and as soon as those gametes the sperm and the egg or release then that Medusa dies and we get back to the polyp body plan okay this is gonna be a little bit weird but what they've done guys is they taken the single clade Medusa so and they're kind of bro turn it up into different groups so I had clavem induces OA for the Hydra and claim Medusa's OA for the OB Elliott which is this one here but those are collectively referred to as Hydra zones within that same clade Medusa's OA I'm gonna have another subgroup and that's going to then be Skye Fazil so these are referred to as the sky for zones but still in the same clade and the Skype as Owens are going to be your true jellyfish okay so the the animal that you're probably more familiar with your jellyfish yes they are in the same plate as the Hydra polyp but yeah and that's Medusa's oh but they are referred to generically as Skye fazilet those are your true jellies okay so this one here is just I think fascinating this is called the lion's mane jelly it's about seven feet across here 120 feet long from the very top of the Bell Medusa all the way down to the bottom of the longest tentacle and it has eight cents sets of tentacles and people are fascinated every time they see Alliance Maine jelly and so as you can see if you're a diver right that would be something that you would definitely want to go up and photograph here like this person is and a big group was doing just that and because it has so many tentacles it was able to sting 50 of them simultaneously I think they were all okay but just kind of funny that that's a such a massive jellyfish okay so the dominant body plan in this group then for the Skyforce Owens is going to be the Medusa okay so here this is one of the organisms that you're going to be asked to look at in your lab this one is the irelia so it's the first little thing that I have under clade Medusa Zyliss Caiphas Owens the irelia life cycle okay so you have I'm single sexed Medusa so here's your mail Medusa I'm making sperm cells here's your female Medusa making egg cells so the sperm will fertilize the egg you get the zygote it's gonna go through cleavage to make a blastula here's your free free swimming plenty of low larval stage it settles down and it going to make kind of what looks like a little polyp okay and this very young area right here is called the young Skyforce Toma and the Skyforce tell my guest looks like a polyp at first but then it changes and it starts to grow taller okay and you can see that there are these lines that are coming here and when you see these lines then we are going to call this the Stroh bola so this is going to be the young Strobel up and that then develops further into the adult Stroh bola which is what I'm going to have all of these layers so these lines right here you can see they start to kind of change shape and they have this jagged ridges here these are called ephra and so this is fascinating what's going to happen then is at the very top this first ephra is going to pinch off and flip over it's gonna be a young stage that will develop further into either a male or a female Medusa after that one does it the next one will do the same exact thing so this next effort will pop off flip over either make a male or a female Medusa so if I can count this it looks like we're gonna get one two three four five six seven eight nine ten eleven maybe about 12 then Medusa male or female coming from the adult Strobel up so in your lab it's going to ask you to fill in the blanks here from this life cycle i believe it asks you for this week the plain yellow larval stage which just looks like this so that's nothing exciting it's gonna ask you I believe for the skyfest oma for the Stroh bola for the effect and then for eventually the adult Medusa and you don't have to tell me if it's a male or female just know that when it reaches reaches the Medusa stage that that is the most mature stage of that lifecycle so it does as well kind of like what we saw in the OB Leah it does alternate a little bit between having a very short-lived Paula but again everything else will be the Medusa body body plan okay the next clade so we're done with the clade Medusa's OA it's going to be the clade anthozoa and these are your CN enemies and this one's pretty easy because this only has a polyp body plan so this group does not alternate between the Medusa body plan and the polyp body plan so that's a little easier to remember here okay so in the life cycle you're going to have sperm and egg coming from the mature adults they're gonna make a zygote there's your plain yellow larval stage it swims for a short period of time settles down into a young polyp and then we'll either mature into an adult male or female so these I know you're familiar with this next slide is going to show you a sea anenome that is in California we actually don't have very many species and our waters but this is one that's very very common so if you've ever gone over to the coast or to Pismo in to the tide pools this is probably one that you have seen and maybe you've even stuck your finger in there and if you stick your finger in here into these tentacles right so this is the polyp body plan this is the mouth this is the oral side the fetal disc would be underneath it we can't see it but they feel sticky right it's it's almost like it's sticking to you well the stickiness that you're feeling when you are touching those tentacles the nomad assists are actually coming out of the needle sites and ITA's are pointing you okay it's trying to sting you but because your your skin is is pretty thick it just feels like it's just little sticky pieces it doesn't hurt you or harm you and if you wouldn't you stick your finger right in it this doesn't like that and so it's gonna basically make itself roll up into a ball you know this one it looks like it's green um from this picture and obviously you can see that but it itself is not green it is green because of a mutualistic relationship that it has so these organisms within the clade anthozoa again you're seein enemies right there going to also include corals and those corals that i mentioned are going to be a little tiny polyp animals like this that secrete calcium carbonate around them that may if that hard coral structure and in order to survive they often will house these little green dots right here those are going to be unicellular algae claudette we've seen that happen with the fungus we're seeing the same thing happen here remember with the fungus it was the lichens but here we have the little green algae and so you see it in coral if I back up just one slide the green that's coming from here is due to the presence then of all of those single-celled green algae inside of the tentacles when this sea anenome is not healthy or if it doesn't have chlorophyll in it for whatever reason it looks pure white and then it's struggling because it's not getting extra sugars that it normally gets when it has the the green algae in it and so the one thing that's really unique about this and why this is important is because the coral reefs they're indicative of massive amounts of biodiversity within our oceans right so similar to things like your rain forests on land and we need to have them there because they bring thousands of species and the whole ecosystem resides within healthy coral reefs and so again just to reiterate this little polyp here is the animal that will secrete coral around it and if you've ever looked at pieces of coral they kind of branch and they go up more than they go out and they go up because they have to make sure these when they're secreting when this polyp is secreting the carsten calcium carbonate rather to make their coral homes they have to make sure that they're going up so that the little green algae inside of their tentacles are able to get light and the mutual exchange then here is that the coral is getting sugars from the algae and the algae are getting protection they're getting a house and they're they're being oriented just so so that they can get massive amounts of UV radiation so that they can pump out massive amounts of sugar and oxygen which the coral polyp actually uses as well okay so that concludes then the two phyla porifera and nigeria please read your book it doesn't go into too too much detail here so we're gonna keep it pretty superficial but if you have any questions about the material as always please please feel free to send me an email okay thank you for listening have a great day