fish are by far the most diverse group of vertebrates with more species than all other groups of vertebrates combined. Now we said that the evolution of Jaws was a very important step. But before we had jawed fish, we had jawless fish and jawless fish actually lack a backbone, but they have cartilage vertebrate. Uh, we're gonna look at two types of jawless fish which are also called cyclist stones, which basically means like circle mouth. You'll see wine second, though much to your chagrin. And the first organism we're gonna look at is the hag fish. This is maybe one of nature's grossest animals. Uh, these air scavengers that actually swim like snakes and the reason they're so gross is you see all these little dots along the hag fish? Well, they actually secrete this water absorbing pre slime material. And basically that priest lime, as it's secreted from those glands along the body, sucks up the water around the hag fish and turns into this gross mucus e kind of slime a substance. This is useful. It allows the hag fish to, you know, escape if it's ah, predators going after their something. But it is also the reason that hag Fisher, horrifying and disgusting like we can see right here now lampreys arguably worse than hag fish. I don't know thistles tough. Both these guys air kind of. Well, there is no one's favorite animal. Let me put it that way. Lampreys are parasites with that characteristic circular mouth, except theirs is filled with these horrible teeth that they used to feed on their hosts. They have a cartilage skeleton, similar to have how hag fish have cartilage vertebra, though it should be noted that their cartilage is actually not made from college. In Lane, Priest cartilage is not made from collagen, which is one of the main component components in most cartilage we see in animals. With that, let's flip the page and turn to some more pleasant organisms.