We also learned (from her) that our program's cosponsor William Gilly, who's been leading many of our science sessions, and who put up with about a million of my geography/biology questions on our Sunday drive from Hearst Castle, is a blogger for Scientific American. There's no shying away from science here. http://blogs.scientificamerican.com/expeditions/2011/06/20/squid-studies-changing-seas-and-shrinking-squid/ I have a good feeling that Seth and I will be learning a lot more about cephalopods in the coming months. Also, if you're looking for a free Humboldt squid to dissect with your class, here's the link for you. http://gilly.stanford.edu/outreach.html. We talked about uses in Art and English. If you want a squid, I can hlep you come up with a project.
So you probably know what's coming for you. 10 things I've learned about cephalopods, mainly Humboldt squids, in the past few days. Hold on to your hat.
1. Squid are all muscle. This makes them about the best possible animal for a snack. They're pursued by everything from dolphins to albatross. Also, when you eat calamari, you're usually eating the mantle (head), cut into rings with the organs cut out from the center. However, the entire squid is edible.
2. The hardest part of a squid is it's beak, which is comparable to a bird's beak. It's made of chiton, and it's very strong. Gilly told us about being bitten by a squid while trying to place a camera on it (a story in itself, I'm sure). He didn't feel the bite because of possible numbing agents in the squid, but he needed 15 stitches. He realized the severity of what was happening when he saw the squid on his arm and red blood on the boat deck. Squid have blue blood.
(Squid beak in center circle)3. Humboldt squid are "reproductive machines." They only live a few years, but their reproductive systems are bigger than their circulatory systems. The female's egg mass is the size of a small car! The male lays spermatophore packages around the female's beak, but no one has actually ever observed their mating rituals.
4. You can't tell the sex of a squid until you cut into it's mantle. Another thing you learn from cutting one open is its approximate age. The tiny (breadcrumb-sized) statolith works like a "black box," recording information about the squid's age and the water temperature during its development. It also helps the squid maintain equilibrium in the water.
(Squid heart. I believe that this is the systemic heart, but it could be a brachial heart. Don't quote me on it.) 5. Squid are some of the only animals on earth to move using jet propulsion. They're only methods of defense are their ink and their escape abilities. They can easily adjust the water flow (yes, I'm simplifying this dramatically) to swim in any direction.
6. Squid ink is edible. Squid can also change the patterns of their inking. They can mix it with water to create a general smokescreen effect. Or they can mix it with mucus and create a pseudomorph, a shape that looks like a tasty treat. That way they can escape while the predator goes after their ink.
(Ink pouch)8. Squid have both chromatophores and photophores. The photophores on the ends of the tentacles look like little drops of light and draw fish in for the squid to eat. There's still a lot of research being done on chromatophores, but know that the entire squid can change color instantly. In one instance, when a camera was placed on a squid, it varied it's color pattern to match the frequency. To see this camouflage ability in action, you can look here. http://youtu.be/ZbNsMVQzca0
9. Humboldt squid have eight arms and two (longer) tentacles. The tentacles have sharp teeth, and can quickly grasp the food. Arms work to keep food from escaping.
(Measuring Squid)10. When measuring squid, you should measure just the mantle. If you hear reports of squid lengths that seem impossibly long, see if the person is measuring by stretching out the elastic tentacle. This is what some people do to exaggerate the size of their finds.
I have one more day to ask questions. Anything you want to know? I also have the name of a cuttlefish breeder if you're interested in helping replenish the supply.
(NOAA research boat for the afternoon exhibition. Whales, plankton, and for some, seasickness.) 
8 comments:
I'm always interested in learning more about cephalopods. They're just awesome!
Why don't people measure the tentacles as well as the mantle?
I had no idea that so much of your time at the Steinbeck Institute would include marine biology! I've learned a lot from reading your blog and will have a fresh perspective the next time I visit the National Aquarium.
Just wait and see if I actually end up posting on my time in front of the jellyfish tank today, take 2. The repeat visit was well worth the time.
They don't measure the tentacles because they're relatively elastic, and some people stretch them out more than others. The mantle should given scientists the same measurement every time.
They don't measure the tentacles because they're relatively elastic, and some people stretch them out more than others. The mantle should given scientists the same measurement every time.
Squids are cool. (Sorry. Nonspecific positive comment there, but I'm really paraphrasing Doctor Who.) Squid dissection also belongs in art class; even the diagrams that aren't technically accurate are incredible. It would be neat to see an art/ biology interdisciplinary lesson.
The Chemistry teacher on the trip paired with one of the English teachers to create joint plan for Of Mice and Men. They're going to be looking at what draws elements and people together and what tears them apart. They'll be starting with order and working towards entropy, so to speak.
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