Organisms
pharyngula | February 18, 2006It's just a photo set of pictures of quail, but I noticed that my right forefinger reflexively twitched at the photo of the Republican lawyer in the middle of them. There may be a neurological explanation for Cheney's shotgun error, after all.
pharyngula | February 17, 2006Argonauta nodosa
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | February 15, 2006In yet another example of evolution in action, investigators have documented morphological changes in the cane toads (Bufo marinus) that infest parts of Australia. They're an invasive species that was introduced in a misbegotten attempt to control beetles that were damaging the sugar cane crop; as it turns out, they are aggressive predators that eat lots of other native fauna, and they secrete toxins that kill animals that try to eat them.
Another feature that contributes to their unwanted success is their rapid dispersal. Individuals can move up to 1.8km per night, occupying new territory at…
pharyngula | February 10, 2006Sepioteuthis sepiodea
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | February 8, 2006a, b, Cranial reconstruction in left lateral (a; shaded area indicates the unpreserved portion) and dorsal (b) views. adc, anterodorsal concavity; al, anterior lamina; an, angular; aof, antorbital fenestra; d, dentary; dg, dentary groove; emf, external mandibular fenestra; en, external naris; if, infratemporal fenestra; isf, foramen on ischium; j, jugal; jp, pneumatic jugal foramen; l, lacrimal; m, maxilla; mc I–IV, metacarpals I–IV; mo, maxillary opening; mt I–V, metatarsals I–V; mvc, median vertical crest; nc, nasal crest; obf, obturator foramen; orb, orbit; pf, prefrontal; pfe, pneumatic…
pharyngula | February 8, 2006Here's some very cool news: scientists have directly observed the evolution of a complex, polygenic, polyphenic trait by genetic assimilation and accommodation in the laboratory. This is important, because it is simultaneously yet another demonstration of the fact of evolution, and an exploration of mechanisms of evolution—showing that evolution is more sophisticated than changes in the coding sequences of individual genes spreading through a population, but is also a consequence of the accumulation of masked variation, synergistic interactions between different alleles and the environment,…
pharyngula | February 7, 2006Carl Zimmer has the lowdown on leeches. The article is right, and they really are beautiful animals—I had a tank full of them last semester (gone now, in a flurry of bloody student labs), and watching them undulate through the water was mesmerizing. They were almost as much fun to watch as my fish.
pharyngula | February 3, 2006Iridoteuthis iris
This big-eyed Hawaiian squid is only 3cm long. It's a sepiolid, or one of the bobtail squids.
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | February 2, 2006As a proud native of the great Pacific Northwest, when an article on one of our noblest creatures was mentioned to me, I had to read it. Here's the center of the story.
In July 2005, nine residents of Teslin, Yukon,
witnessed through a kitchen window a large bipedal
animal moving through the brush. The next morning, they
collected a tuft of coarse, dark hair and also observed a
footprint measuring 43 cm in length and 11.5 cm in width.
That's right: physical evidence, a footprint and hair, from…Bigfoot. The Sasquatch. A sample captured in the wild and brought into the lab. Pinned against the…
pharyngula | February 2, 2006Hey, you know that adorable teeny tiny fish species, Paedocypris, that I was drooling over the other day, and mentioning how cool it would be to work with?
It may be extinct already.
pharyngula | February 2, 2006
apostropher has the link to the video: penis fencing flatworms. They are impressively athletic.
pharyngula | February 1, 2006
Olduvai George does it again: another gorgeous, art-filled post on ancient and modern crocodiles, including a reconstruction of the recently discovered Triassic Effigia.
pharyngula | January 26, 2006
Here's a nifty video (mpg) of an octopus confronting an ROV working off Vancouver Island. The poor thing was just trying to crush and eat an interloper (or perhaps disassemble it for spare parts to use in its high-tech scheme to take over the world), and the ROV operator uses its thrusters to fling debris at it and drive it away.
It's quite a battle, and the octopus holds on for a surprisingly long time in the face of an extremely obnoxious machine.
pharyngula | January 25, 2006I saw on Muton, and several readers have mentioned it to me, this article about the world's smallest vertebrate, fish of the genus Paedocypris. It's a gorgeous translucent cyprinid, so is somewhat related to my favorite fish, Danio rerio. They live in cool, slow moving water in peat swamp forests of Southeast Asia. One female, only 7.9mm long, contained about 50 eggs, so they know it was sexually mature.
Living Paedocypris progenetica, CMK 18496, (a, b) male, ca 9 mm; (c) female, ca 8.8 mm.
That size isn't at all shocking—my zebrafish larvae at about that size are active hunters with…
pharyngula | January 24, 2006
First, a tiny bit of quantitative morphological data you can find in just about any comparative anatomy text:
mammal
number of vertebrae
cervical
thoracic
lumbar
sacral
caudal
horse
7
18
6
5
15-21
cow
7
13
6
5
18-20
sheep
7
13
6-7
4
16-18
pig
7
14-15
6-7
4
20-23
dog
7
13
7
3
20-23
human
7
12
5
5
3-4
The number of thoracic vertebrae varies quite a bit, from 9 in a species
of whale to 25 in sloths. The numbers of lumbar, sacral, and more caudal vertebrae also show considerable variation. At the same time, there is a surprising amount of invariance in the number of cervical vertebrae in…
pharyngula | January 23, 2006Since I mentioned yesterday that penis size mattered, upon stumbling on this article about the horrific effects of a trematode infestation, I thought everyone might enjoy a grim and vivid picture of what trematodes can do to a poor, innocent mollusc.
This is a photo of a trematode, or fluke. Trematodes are parasitic flatworms with very complex life cycles; this particular one is a cercaria, or tailed larva. They swim about and infest various hosts at various stages, proliferating and spreading through tissues, before moving on to infect the next host in their cycle.
This particular trematode…
pharyngula | January 22, 2006I hate those commercials on cable TV for Enz*te, that fake "male enhancement" product that promises a "boost of confidence" for all the guys who take their little pill. I don't believe it, of course—it's probably a concoction of sawdust and rat droppings. But the phenomenon of male confidence as a function of the size of their physical attributes might just have some validity.
AL Basolo, who did some well-known work on mate preference in swordtails a few years ago (short answer: lady swordtails prefer males with longer swords), has a couple of new papers on the subject. She has looked at…
pharyngula | January 19, 2006
Nematostella, the starlet anemone, is a nifty new model system for evo-devo work that I've mentioned a few times before—in articles on "Bilateral symmetry in a sea anemone" and "A complex regulatory network in a diploblast"—and now I see that there is a website dedicated to the starlet anemone and a genomics database, StellaBase. It's taking off!