Because I'm sure you all wanted to know more
Since we were talking about echinoderm develoment, I of course had to spend time trying to find pictures of the "tumor-like" adult on the larvae (although technically I believe it's called a juvenile rather than adult). I couldn't find great pictures online although I know they exist (I haven't figured out the best search terms it seems). The first pic is of a young pluteus (sea urchin larvae). The second is of an older pluteus. See the brown growth? That's the juvenile which will attach, reabsorb all of the larval features and crawl off to become an adult. The old plutei are so strange looking with these brown outgrowths which wave around small tube feet and spines. Unfortunately this picture does not convey the bizarreness of it all and how it just looks so very wrong.
8 comments:
Those things are so beautiful. If you find any more neat pictures I'd like to see them. Sounds like you've actually looked at live ones under the microscope (at Friday Harbor?). That must be extraordinary!
Way cool
Yesterday I started lecture with, "I had the audacity to tell some of my biologist friends that echinoderms weren't all that interesting, and, well, they let me know how wrong I was. So the theme of today's lecture is 9 reasons echinoderms are really cool." It was a lot of fun.
During my embryology course at Friday Harbor, we spent a significant amount of time tracing the complete development of echinoderms - from egg and sperm to juvenile (which is basically a tiny adult). Man, day after day of looking at sand dollar, sea urchin, sea cucumber, and sea star larvae kinda leaves an impression. I had little bowls of each of those to look at, draw, clean and feed. For a while afterwards, if you had asked me a question about or shown me a picture of any echinoderm I probably would have run from the room screaming. But that was several years ago, and I can now appreciate how cool they are. And I must admit to being a bit partial to sea cucumbers because of it. They are kinda the odd ball of the group (I mean a ciliated barrel? You couldn't make this stuff up) and their pentacula are just cute. But then there is the messy gastrula of sea stars.... Okay, I need to just stop, otherwise I'll go on forever.
Lisa, your class room comment made me laugh. I'm glad that I was able to give you a few new things to talk about. I think all animals have cool quirky things about them (well, except for maybe vertebrates, but they're such a small group)
Well, I think there are plenty of quirky things about vertebrates.
Manatees have prehensile lips. Coelocanths stand on their head.
Caecilians? Lampreys? Pretty quirky.
Jenny gave me a bee in my bonnet to point out that vertebrates do some interesting stuff. (Abby, you were kidding, right?)
Here's some brainstorming: There are some great wierdnesses in fish. How about the wrasses that only become male when they're big enough to defend territory (and are female before that)! I think they're called blue-tailed wrasses. Some fish have REALLY weird larvae also. Oh, and the flounders and soles. They start out bilateral and then one eye migrates over the top of the head and onto the other side to make the weird adult with both eyes on one side.
In other vertebrate groups there's the hyena where females have penis-like things as some sort of status symbol. Amazing array of chemicals produced by frog skin. The whole internal developement thing in mammals (and other groups like some sharks and fish and the gastric-brooding toad). I always thought that 4 stomachs in ruminants was pretty cool, and light sensitive '3rd eyes' on top of the head in some lizards. Tail resobption and leg development in frogs (not to mention digestive transformation from herbivore to carnivore). Sonar in bats and dolphins, too. Language dialects in birds and whales... Aren't these cool and quirky?
Yes, yes, I was kidding about the vertebrate thing. I like to pick on vertebrates alot because they get the lionshare of the attention even though they are not as diverse as several other groups. But I do appreciate that even they have some cool things going on.
Oh, the defenders of the verts come out. Next year (and it will be spring 2008 rather than this fall, yea!) I'll have to come back to you guys when I'm teaching Vert. Yesterday I took my class to the aquarium in Pittsburgh (which I should post about) and my students finally learned not to ask about the fish. "What is that?" "Some vert"
Plants fungi and inverts are where it's at!
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