 I'm kind of angry at this lecture right now because there are so many cool things in this lecture. Oh my gosh, it's mind blowing. Arthropods. Arthropods are by far the most diverse group of animals. So they're protostomes, but almost 80% of all animal species on our planet are arthropods. So if you just think about that, it should blow your mind. Now, look at what we've got. We've got spiders, they're arthropods. We've got crabs, those are arthropods. We've got insects, arthropods. Now look at the breakdown. Insects make up almost 75% of arthropods, but you also have a bunch of other stuff. So look at... You have other arthropods? Whoa, look at... So no, this was insects make up almost like way more than 75% of arthropods, but almost 75% of all critters are insects. That's incredible. This is a very interesting slide. Now, let's go look at different kinds of arthropods. We have the chelicerates, which are... They include spiders, horseshoe crabs are part of this group, scorpions are part of this group. That thing, which is like some sort of desert nightmare, and I don't know what that is either, but I think that's like a giant crab. No, that can't be a crab if it's a chelicerate. It's got to be some kind of spider. We're going to take a closer look at the tick, and I just apologize for this. I'm not a fan of ticks, but I need to blow your mind for just a second. Do you think that I've got my little pointer on the tick's head? Haven't you always heard that ticks like embed their heads in your body, and then they suck your blood? I don't like ticks. Well, that isn't the tick's head. I'm about to show you the tick's eyes, and it is going to creep you out. Do you see them? That's its eye right there. And look, here's another eye right there. That's its mouth. It has a specialized mouth. It like sticks its little things, like it's a little syringe proboscis twanger thing that sucks your blood and gets all fat and stuck in there, but its eyes are actually out here on this body. Look at how he's standing. He's standing here going, oh, come to me, my little furry, anything that has blood that I can yumpsialize, it hangs out on the ends of grasses so that when you walk by it like sticks to you, and then they walk super light, like you cannot feel a tick walking on you. I mean, a spider? I do not want to think about this too much, but if a spider is crawling on you, it, like you can feel it, and you get all ying ying ying. And the grossest thing about ticks is that they crawl on you and you don't feel it because they, I don't know why they're like slow and steady, and they just like stealth crawl. Ugh, ugh, okay, let's move on. How weird is this? I, millipedes, do not creep me out at all. Like I can hold a millipede, I can hold like 10 millipedes, and they can crawl all over my hands. We had an exchange student from Japan, and you know, my kids were however old they were, and they're boys, and they're obsessed with anything that's critter-ish, and so we would go camping and we'd take her with us, and the boys would collect millipedes, because like millipedes are the coolest thing ever, and they're not dangerous at all. Sometimes they're stinky, they make a poison stink, but they're like these little round, funny caterpillars and they come out at night. Look at all those legs, like they're just cool, but millipedes are friendly. I never was quite able to convince Moino that millipedes are friendly. She was like, I don't think so, friendship only goes so far. She did the whole, when millipedes came around, but for me, millipedes are cool. Centipedes on the other hand, these are just flavors of arthropods. Centipedes give me the creeps. That thing, if I saw that in the middle of the night, oh, I can't even look at that thing. That's like centipedes make, and centipedes can bite, and they're more dangerous. So I feel like my little brain pathways have been wired that millipedes are friendly buddies. Centipedes can bite you and hurt you, so don't be friendly with centipedes, but ticks aren't friendly either. I don't know, it's interesting. What else, crustaceans? Oh, man, we could spend eight days on crustaceans, because they're incredible. Salabugs are the only land crustaceans. The rest of them live in the water. There's all sorts of parasitic crustaceans, including that one. Remember when we talked about parasites? I think we talked about the one that came in and pretended like it was the fish tongue, like ate the fish's tongue and then just became its tongue. Those are crustaceans. Barnacles, oh, jeez. If you, yeah, barnacle music video, if you're bored, go watch that thing, because barnacles, barnacles are epic organisms in the animal kingdom, because they actually have the longest penis to body size ratio of any animal on the planet. So I mean, you got to be, like, impressed with a barnacle. Okay, and then, of course, we have to talk about our insects. Insects are wholly incredible diversity. If insects went extinct, game over. We're done. Sorry, like, you're done. We all die the minute the insects go extinct. If humans go extinct, probably all the other critters on the planet are going to be like, oh, hallelujah. Thanks for getting rid of those things. Those things were awful. I think this is the end of our, yeah. This is the end of our treatment of arthropods. It's pretty much a tragedy that we can't spend more time on them. But let's go ahead and talk about one group of deuterostomes, and that's the kind of germs.