Organisms
pharyngula | June 26, 2008
This is an amphioxus, a cephalochordate or lancelet. It's been stained to increase contrast; in life, they are pale, almost transparent.
It looks rather fish-like, or rather, much like a larval fish, with it's repeated blocks of muscle arranged along a stream-lined form, and a notochord, or elastic rod that forms a central axis for efficient lateral motion of the tail…and it has a true tail that extends beyond the anus. Look closely at the front end, though: this is no vertebrate.
It's not much of a head. The notochord extends all the way to the front of the animal (in us vertebrates, it…
pharyngula | June 23, 2008That smart guy, Carl Zimmer, has written an article on those smart molluscs, the octopus. I like that his conclusion is that we can't really judge their intelligence, because it is different than our own.
That's the same answer I give to questions about the existence of intelligent life in the universe. I suspect that it's there (but rarer than most astronomers seem to think — intelligence is an extremely uncommon adaptive strategy here on Earth, as is probably likewise elsewhere), but that it will be radically different in intent and action than our own, as different as we are from a squid,…
pharyngula | June 13, 2008Nautilus pompilius
(from Nature 453, 826 (12 June 2008) — doi:10.1038/453826a; Published online 11 June 2008)
pharyngula | June 2, 2008
We're all familiar with Pavlov's conditioning experiments with dogs. Dogs were treated to an unconditioned stimulus — something to which they would normally respond with a specific behavior, in this case, meat juice which would cause them to drool. Then they were simultaneously exposed to the unconditioned stimulus and a new stimulus, the conditioned stimulus, that they would learn to associate with the tasty, drool-worthy stimulus — a bell. Afterwards, ringing a bell alone would cause the dogs to make the drooling response. The ability to make such an association is a measure of the…
pharyngula | May 25, 2008
It's another transitional form, this time an amphibian from the Permian that shares characteristics of both frogs and salamanders — in life, it would have looked like a short-tailed, wide-headed salamander with frog-like ears, which is why it's being called a "frogamander".
Complete specimen in ventral view, photograph (left) and interpretive outline drawing (right). Abbreviations: bc, basale commune; cl, cleithrum; cv, clavicle; dm, digital elements of the manus; dt3, distal tarsal 3; fe, femur; h, humerus; ic, intercentrum; il, ilium; is, ischium; op, olecranon process of ulna; pc,…
pharyngula | May 24, 2008
We mammals have been beaten again. Shrimp have more sophisticated eyes than we do, with the ability to see things we can't, and I'm feeling a bit envious.
There are a couple of general properties of light that can be captured and measured with a light detector. One is the amplitude of the light wave, which we see as differences in the intensity of light. This is the most basic measurement of a photoreceptor, sensing the raw amount of energy being transmitted. Another property is wavelength, which we perceive as the color of light. Many mammals are incapable of detecting the wavelength,…
pharyngula | May 23, 2008Octopus cyanea
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | May 16, 2008Loligo forbesi
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | May 15, 2008
By now, everyone must be familiar with the inside out organization of the cephalopod eye relative to ours: they have photoreceptors that face towards the light, while we have photoreceptors that are facing away from the light. There are other important differences, though, some of which came out in a recent Nature podcast with Adam Rutherford (which you can listen to here), which was prompted by a recent publication on the structure of squid rhodopsin.
Superficially, squid eyes resemble ours. Both are simple camera eyes with a lens that projects an image onto a retina, but the major details…
pharyngula | May 9, 2008Wired has a pretty gallery of images from the recent Colossal Squid necropsy. If you've ever wondered what a pile of squid guts would look like on a table, here you go.
It's too bad the images aren't quite large enough to use as wallpaper on my laptop.
Oh, and those colors—that's exactly what slug guts look like, too. We natives of the Pacific Northwest have many opportunities to get familiar with those.
pharyngula | May 9, 2008Octopus marginatus
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | May 4, 2008I love bats — they're almost as glamorous as squid. So I am greatly dismayed to learn that there is a virulent bat illness spreading out of the northeast US, a serious die-off that has as one of its symptoms a fungal growth that has led to calling it "white nose syndrome". Bats are behaving oddly, starving to death, and dropping dead.
Earlier I was complaining about the limited imaginations of television executives, who do such a poor job of translating science to the screen. Here's a story full of drama and tragedy, with photogenic stars (the bats!) and scientists doing real, serious…
pharyngula | May 2, 2008Sepioteuthis sepioidea
Since I saw Iron Man last night (short review: AWESOME!!!), I thought I'd try to find a cephalopod with a similar red and gold color scheme…and didn't get very close. But this one does have the sleek look of a rocket-propelled machine, so it will have to do.
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | April 27, 2008Watch the communal spawning of squid off the California coast.
It's the last thing they do: one huge orgy of mating, and then they collapse, spent and dying.