Hi,

I've been writing a science Q&A blog since 1999. USA Today and the Globe and Mail have run almost all my [url=http://www.wonderquest.com/index.htm]WonderQuest[/url] columns. My daughter thought you folks might be interested, too. So, I've got a [url=http://www.wonderquest.com/teachers-science-corner.htm]Teacher's Corner[/url] going on my web site and a monthly newsletter for you. By the way, I'll be posting my monthly column here for the next few months, if you'd like.

Here's my newsletter for this month; I hope you like it. And, more importantly, find it useful. Here's my email address, in case you want to subscribe (free) or send me comments:
[email="contact@wonderquest.com"]contact@wonderquest.com[/email]


July's e-Newsletter for Teachers

An octopus is a cousin to slugs and snails

A provoked greater blue-ringed octopus. When disturbed, the octopus switches from its normal drab brown/yellow color to bright yellow with bold blue rings. Photo courtesy of Roy L. Caldwell © Used with ermission.

Q: Is an octopus a reptile, mammal, or amphibian? Or is it just a fish? Christine, Chardon, Ohio

Q: How do blue-ringed octopuses breathe? Priscilla, Tootgarook, Victoria, Australia

A: An octopus is not a reptile, a mammal, or an amphibian (though it can live short periods of time out of water — long enough to climb out of a tank at night and eat shell fish from other tanks). It is not even a fish.

The ancestors of octopuses branched off from the ancestors of vertebrates more than 550 to 600 million years ago. Annelids (for example, earthworms and leeches) and arthropods (insects, lobsters, and the like) may be their closest major related groups, says biologist [url=http://ib.berkeley.edu/people/faculty/person_detail.php?person=133]Roy Caldwell[/url], a professor at the University of California.

Octopuses are in the mollusk group — muscular slimy creatures such as slugs, snails, mussels, oysters, squids, and cuttlefish.

Although not fishes, all octopuses (including the blue-ringed octopus Reader Priscilla asked about) breathe like fish with gills. They suck water through two internal gills, just behind two of their three hearts. The gills extract oxygen and blow the water out through a tube, called a "siphon" or "funnel". The octopus can shoot through the sea — in reaction to the expelled water jet — although he usually walks or crawls.

When attacking prey, an octopus gets close, leaps forward by spurting a water jet backwards, and grabs his lunch — perhaps a crab or fish.
By the way, all octopuses have poisonous bites. The golf-ball size blue-ringed octopus of Australia, however, is the only octopus whose bite is known to kill humans. The poison can stop a person’s heart and breathing in several minutes. Without medical care, this can kill the victim. We have no antidote. With medical aid to maintain ventilation, though, victims usually recover.
There is another species, called Octopus mototi, whose name on the Rapa Island in the South Pacific, literally means "poisonous octopus," says Caldwell. We don’t know if this creature is deadly, "but I would not let one bite me."

Further Reading:

[url=http://www.wonderquest.com/octopus-teeth-eyes.htm]Do octopuses have teeth?[/url] WonderQuest

[url=http://www.wonderquest.com/octopus-women-size-schedule.htm]How long are an octopus' arms? What is a siphon? Do octopuses have bones? How did octopuses get so intelligent? Why don't octopuses have bones? How do octopuses change colors?[/url] WonderQuest

Roy Caldwell, "Death in a Pretty Package: The Blue-Ringed Octopuses." Freshwater and Marine Aquarium Magazine, 23 (3): 8-18.

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Related Lesson Plan, Courtesy of Discovery Education
(Click [url=http://school.discovery.com/lessonplans/programs/octopus/]link[/url] for the entire plan)

The Amazing Ocotpus

Learning objective: Some animals can change body color to blend in with their surroundings. This ability both protects them from predators and allows them to sneak up on prey, since they are nearly invisible.

Grade Level: 3-5, 6-8

Topics: Animals: octopus and other cephalopod

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Teacher's Comments, so far

  • Comment: It's a good idea, but needs to be marketed (i.e. made visible to science teachers). You might consider putting a couple of different things up for a couple of different grade levels.
    Jesse Johnson, physicist, University of New Mexico
    7 May 2007
    Reply: Good thought, Jesse. I need help from teachers: what's good for different grade levels?

    Comment: Different teachers will want different things. Many teachers will use only that material that they can relate back to their state or district benchmarks or guidelines. The problem is that different states all have different guidelines! On the other hand, many states use National benchmarks to guide the development of their own standards, such as using Project 2061: [url="http://www.project2061.org/"]http://www.project2061.org/[/url]
    Eric H. Chudler, neuroscientist, Director of Education and Outreach, University of Washington
    7 May 2007

    Reply: I'll add a lesson guide that relates to the Q&A featured. Figuring out what teachers can use is difficult, though. I need feedback.

    Comment: "Nice Science Link," says Steve Brügge.

    "April Holladay is a local writer who has a wonderful column in USA Today called WonderQuest. I've known her for many years and always find her columns accurate and well written.

    "She has a new web page aimed at teachers."

    See: [url="http://www.wonderquest.com/teachers-science-corner.htm"]http://www.wonderquest.com/teachers-science-corner.htm[/url]

    Steve Brügge
    Science Teacher & Webmaster, Eisenhower Middle School
    [url="http://www.aps.edu/aps/eisenhower/brugge/brugge.html"]http://www.aps.edu/aps/eisenhower/brugge/brugge.html[/url]
    15 May 2007

    Reply: Thanks, Steve. Kudos from you is high praise indeed. Steve's science class regularly wins the NM Science Bowl competition and even the regional Science Bowl.

    Comment: WOW! Double WOW! I'm impressed. Such talent, and so much work. Where do you find the time? Have you enslaved a bunch of Munchkins that do all this?
    Walt Murfin
    15 May 2007

    Reply: Actually, there are many Munchkins behind the scenes. I haven't exactly enslaved them, but I couldn't do it without them. Click here to see the 500 or so [url=http://www.wonderquest.com/Contributors.htm]contributors[/url].

    Comment: I love your newsletter!
    Bobbie, Vocational Rehabilitation Specialist
    2 July 2007

    Comment: As a home schooling parent of kids 4 and 6.5, your articles are invaluable!
    Curtis, home-school teacher
    6 July 2007