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Natural History
Feb. 20th, 2006 07:56 amToday's phylum is the LORICIFERA. I was going to yawn and say they were yet another bunch of marine worms with bristles at one end for catching food, but check out how funky they look. They can retract the head part into the base. They're microscopic and live in sand and were only discovered in the seventies, so not much is known about them.
In fact it's getting obvious there must be an awful lot of phyla out there, perhaps represented by only a few species, which we haven't even discovered yet, and possibly never will. Whole body plans, as distinct and different as a sea urchin is from a butterfly.
In fact it's getting obvious there must be an awful lot of phyla out there, perhaps represented by only a few species, which we haven't even discovered yet, and possibly never will. Whole body plans, as distinct and different as a sea urchin is from a butterfly.
Natural History
Feb. 19th, 2006 06:00 pmToday's phylum are the PRIAPULIDA. You will be shocked to learn they are marine worms. They look a bit rude, hence their name, the derivation of which is left as an exercise for the reader. They live in sand or mud at the bottom of the ocean and catch things with their spiny mouths.
Not again! Frankus, get away from that off-switch!
Not again! Frankus, get away from that off-switch!
Natural History
Feb. 18th, 2006 10:15 am![[livejournal.com profile]](https://www.dreamwidth.org/img/external/lj-userinfo.gif){kind=small}
frankxcat switched off the computer while I was doing this one yesterday, which made me very cross.Today's phylum is the MICROGNATHOZOA. You can tell at a glance that they are obviously the "small-jawed-animals". In fact they have the most complicated jaws in the animal kingdom, with thirty-two moving parts. Fortunately they are only about a tenth of a centimetre in length. Not they, it, there's only one species so far, which was only discovered in 2000 in a hot spring in Greenland. Hilariously, Morphology magazine put a picture on the cover but accidentally said the thing was a metre and a half long. Only on Skull Island!
Natural History
Feb. 16th, 2006 07:37 pmWell! *claps hands* Which of my neglected LJ projects shall I return to first? I know - it's time for more of Mother Nature's boundless creativity! So today's phylum is the ENTOPROCTA. These are the goblet worms, about 150 species of little marine thingies that filter feed with the help of ciliated tentacles around their mouths. Rudely, their anuses are inside the ring of tentacles too - other animals sensible put their bottoms outside their feeding mechanism.
In 99% of cases, you had never heard of them before this posting. I hadn't. (I suspect that in 99% of cases, you will never hear of them again.)
And here's a picture.
Still not up to the Deuterostomes (you, me, starfish). Only five more phyla to go, though.
In 99% of cases, you had never heard of them before this posting. I hadn't. (I suspect that in 99% of cases, you will never hear of them again.)
And here's a picture.
Still not up to the Deuterostomes (you, me, starfish). Only five more phyla to go, though.
Natural History
Nov. 7th, 2004 09:20 pmQuestions:
1. Why have only eukaryotes - that is, organisms such as plants, animals, and fungi, whose cells have nuclei - had the ability to form multicellular creatures with different types of cells? Why can't prokaryotes such as bacteria do this?
2. All known organisms share a common ancestry. In Life: An Unauthorised Biography, which I'm currently reading, the eloquent author Richard Fortey maintains this means life only arose once on Earth. Is that necessarily the case?
3. Why green? Could the photosynthetic pigment have been another colour?
"It's going to worry me until I find out." - the Doctor
1. Why have only eukaryotes - that is, organisms such as plants, animals, and fungi, whose cells have nuclei - had the ability to form multicellular creatures with different types of cells? Why can't prokaryotes such as bacteria do this?
2. All known organisms share a common ancestry. In Life: An Unauthorised Biography, which I'm currently reading, the eloquent author Richard Fortey maintains this means life only arose once on Earth. Is that necessarily the case?
3. Why green? Could the photosynthetic pigment have been another colour?
"It's going to worry me until I find out." - the Doctor
Natural History
Nov. 2nd, 2004 08:46 pmToday's phylum is ROTIFERA, the, er, rotifers. They were discovered by Dutch microscope expert Leeuwenhoek around 200 years ago. (Think of it - they were there the whole time and we had no idea. There's something eerie about that. At least with germs we knew something was going on.) These guys are multicellular, but extremely tiny, the size of single-celled organisms. They have a "wheel" of cilia around their mouths (rota is Latin for wheel) for grabbing food, and a foot with a "toe" used to attach themselves to surfaces. There are about 2000 species, typically found in fresh water.
Natural History
Nov. 1st, 2004 09:26 pmToday's phylum is the NEMERTEA, the ribbon-worms, of which there are around 800 species.
There are two classes:
- Anopla (use their proboscis like a lasso to catch prey)
- Enopla (use pointy teethy things called stylets to zap their prey with poison)
There are two classes:
- Anopla (use their proboscis like a lasso to catch prey)
- Enopla (use pointy teethy things called stylets to zap their prey with poison)
