"He must, so know the starfish and the student biologist who sits at the feet of living things, proliferate in all
directions. Having certain tendencies, he must move along their lines to the limit of their potentialities."

John Steinbeck - Log from the Sea of Cortez

Friday, February 19, 2010

Shubin and Colbert

Today, my vert zoo students and I talked about the fish/amphibian transition that took place in the early part of the Devonian. Of course, Tiktaalik came up. A couple of years ago, I had the pleasure of seeing Neil Shubin in an ALLELE talk at the University of Alabama, not long after Your Inner Fish came out. He's a very funny, very engaging speaker. I tried to show my students his appearance with Stephen Colbert, only to find that Comedy Central has pulled it from YouTube. But, it's still there on their site. Embedding won't work, so here's the link.

Guys, meet Neil Shubin....

Wednesday, February 17, 2010

One of the bad ones

An overly dramatic look at Chironex fleckeri, the Indo-Pacific box jelly.

Tuesday, February 16, 2010

In fact...

...it's time for some night music. Maybe some Avett Brothers.

Words...

My zoology guys are about to tackle the Phylum Cnidaria. It's tough to get excited about the poriferans, but when you leave the sponges behind and move on to the jellyfish and their kin, things can ratchet up a little. And there's the added benefit of some goodies for the literature/philosophy guys too.

One of the things I love about biology is the degree to which it draws upon other disciplines for its terminology and its descriptions. I'm sure that's true to some extent in all fields - psychiatry has it's Oedipus complex and computer guys have their trojan horses. Still, I think biology makes greater use of literary allusions than the rest of them put together. I mean, we use a dead language just to name our organisms. From the Red Queen Hypothesis to the Ghost of Competition Past, there's plenty of opportunities to prove to the crowd that, yes, I read that book.

We lean on the Greeks a lot, and the cnidarians are a prime example. There's Hydra, the little freshwater polyp that draws its name from the nine-headed sea serpent of Greek mythology. And then there's the medusa, the free-swimming, sexually reproducing stage found in most of the cnidarian classes. They're named, of course, for one of the great villians of all time, the gorgon with serpent hair, so hideous that men turned to stone when they gazed upon her. Medusa was beheaded by Perseus, who later would use her still potent head as a weapon. Here she is, as envisioned by the great Harry Harryhausen in Clash of the Titans...





The references to creatures like Hydra and Medusa in the cnidarians are a tribute to their most characteristic feature. All cnidarians possess cells known as cnidocytes, which contain specialized organelles called cnidae. There are a variety of cnidae, but the ones that the phylum are known for are the stinging and food-gathering organelles known as nematocysts. Within certain cnidocytes are capsules which contain coiled, hollow threads and have a hairlike triggering mechanism, a cnidocil, on their external surface. When the cnidocil is stimulated, on contact with a potential prey item or an unfortunate swimmer, the nematocyst penetrates the object and the thread is thrust into it. This is one of the most rapid movements in the animal kingdom, taking place in a matter of microseconds. The toxins contained in the nematocyst are potent - some of the most potent we'll see in the animal kingdom. But that's a story for another day. It's late.

Whales...

I'm "reading" (actually, listening - it's an IPod/running thing) to a new book by Phillip Hoare called The Whale: In Search of the Giants of the Sea. It's both a natural history and a history - a natural history of the great animals themselves and a history of man's interactions and fascinations with them. I'll periodically have whales on the brain. Right now, we're reading about sperm whales. World's largest predator. Almost 70 feet long. Diving to depths of well over a mile - in search of giant squid. And the hero of, like it or not, the great American novel. Not a bad resume...



And,how spectacular is this?

Tut was a wreck..

DNA analysis of the mummified boy king, and associated mummies, indicate that:

1. His parents were probably siblings.
2. He may have suffered from juvenile aseptic necrosis.
3. He may have fathered children that died from congenital disorders.
4. A fractured femur may have led to an infection that killed him.
5. He probably suffered from the worst form of malaria.

But he had some cool stuff.

One of the sadder things...

...you'll see today. A bahaba, a species of sciaenid fish from the western Pacific, was caught and sold this week.  That might not sound like much of a news item, until you hear the rest of the story. The bahaba (Bahaba taipingensis) is critically endangered, primarily as the result of massive overfishing. You see, the swim bladder of the bahaba is thought to have medicinal powers. This 300 pound fish was the first of its kind to be caught in more than a year, and sold for the equivalent of $500,000. A pretty magnificent fish that will soon go the way of the dodo. Or, more appropriately, the way of the rhino, and for much the same reasons.

I like the comment at the end of this article. What do you think we could get for the dried and powdered remains of a Chinese herbalist?

Monday, February 15, 2010

Your metaphysical question for the day...


If you're being charged by a 4 ton elephant, is it running toward you? Or just walking really fast? As best I can tell, the "answer" seems to be, "Well, what do you mean by running?"

How could you possibly have fun with a jellyfish?





Sponges, of course, can have fun with just about anybody. They are, after all, the life of the oceanic party - a living, flow-through filtration system that can deliver the party treats quicker than Dominos. The delivery system is provided by specialized cells called choanocytes. Choanocytes are flagellated, and the action of the flagella create a current bringing food-laden water into the sponge. Choanocytes are also equipped with a collar of microvilli around the base of the flagellum. Food particles carried with the water are trapped in this collar, ingested, and passed along to other cells for utilization within the body of the sponge. While sponges take on a vareity of body plans, the utilization of choanoctyes to move water and collect food is universal. Modern single-celled choanoflagellates are structured similarly, suggesting that they may share a common ancestor with sponges.

Take a look at the movement of water through sponges as demonstrated here. Be forewarned, the music's not as cool...