Friday Cephalopod: pretty and poisonous


Grrlscientist asked me for a blue cephalopod the other day, and what do we all think of when blue cephalopods come up? Blue ringed octopuses, of course. So lovely, and so deadly.

i-4ccdbe38a825b9ee355b18c6f2bbc031-hapalochlaena.jpg
Hapalochlaena

Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.

Comments

  1. says

    It amazes me that there are people who keep those as pets. I’ve seen people with cone shell snails in their aquarium too.

    Risking your life for a pretty decoration in the living room… ugh.

  2. Andrew says

    mmmmm… Pretty sea-thing. Must touch… I used to find these occys all the time in various tidal pools in my extreme youth. Fortunately I had been indoctrinated by my parents not to touch anything that they had not previously affirmed as safe.

  3. Fernando Magyar says

    Evolving Squid,

    It amazes me as well but more so because unless the person who is the keeper has a good understanding of saltwater aquarium maintenance and ecosystems these pets tend not to fare very well. So it’s more detrimental to the well being of the pets than the owners.

    I myself keep saltwater creatures that I collect in the Sargassum weed that is about to wash up on shore near my home in Florida. These animals were dead creatures floating to begin with so I don’t feel too bad keeping them around a bit longer.

    BTW growing up in Brazil I learned early to shake the spiders and scorpions out of my shoes before putting them on. Of course I never told my mother about the poisonous snakes that my friends and I would catch and release.

  4. Icequeen says

    I once encountered these on a dive where I was swimming with manta rays. The contrast of huge harmless animals and this tiny killer was a great realization. My mom freaked out when I told her how big the mantas were, but I probably shouldn’t have added that that 1.5 inch blob had a bigger potential to kill me.

  5. G. Tingey says

    In what way are they deadlY?
    Are they like cone-shells with a poisonour injection, or do they have some other tixn-introduction mechanism.

    In fact, more info. generally, please!

  6. John B says

    Found this, for those interested in a little video of these creatures. Nothing too exciting, just one of these little guys swimming around.

  7. Ian H Spedding FCD says

    grigory wrote:

    octopuses or octopi?

    I thought it was agreed to be ‘octopodes’.

    Which was interesting because that suggested the singular of Antipodes should be ‘antipus’ and that would make Wilkins an Antipusian…

  8. Geoffrey says

    They also seem to be able to secrete venom directly into the water, as a way of incapacitating tasty crabs without having to get a beakhold; I saw one researcher mentioning mild localised neurological effects in his hand after dipping it in a tank that had previously held a large blue-ring.

    The good news is that with proper resuscitation, the chances of recovery are pretty good; it paralyses muscles and breathing, but it doesn’t do a lot of damage elsewhere and if air supply can be maintained the effects wear off after around 24 hours.

    Incidentally, although the body is usually yellow to brown, they come in a range of pretty colours including pink (scroll down).

  9. David Marjanović says

    Which was interesting because that suggested the singular of Antipodes should be ‘antipus’

    Correct.

    and that would make Wilkins an Antipusian…

    Incorrect. The stem of the word is antipod-. The -s is an ending (for the nominative singular) just like the -es is an ending (for the nominative and accusative plural); and the ancient Greeks didn’t like saying “ds”, especially not behind a long vowel, so they dropped the “d”.

  10. David Marjanović says

    Which was interesting because that suggested the singular of Antipodes should be ‘antipus’

    Correct.

    and that would make Wilkins an Antipusian…

    Incorrect. The stem of the word is antipod-. The -s is an ending (for the nominative singular) just like the -es is an ending (for the nominative and accusative plural); and the ancient Greeks didn’t like saying “ds”, especially not behind a long vowel, so they dropped the “d”.

  11. says

    I wish the Friday Cephalopods contained more info about the creature, like where they live, how big they are, and why the picture is especially interesting.

    BTW Firefox spell-checker thinks that cephalopods is not even a word, and suggests encephalopathy, hydrocephalus and encephalographic

  12. says

    We used to find blue rings fairly regularly in the tide pools around Okinawa. (Of course, we also found white phosphorus, land mines, grenades….)

    My 8th grade science teacher was a PhD marine biologist with about 15 good size aquariums in her classroom. :-)

    I know she had at least one tank that was placed in an off-limits part of the room with a couple of different venomous (NOT poisonous) critters in it.

    Cheers.

  13. says

    thanks for the picture! i love those pretty little guys and if i kept an aquarium, i would love to keep one as a pet. considering that my apartment was transformed into an aquarium yesterday due to a flood from upstairs, it makes me wonder what i am waiting for.

  14. says

    Octopodes are extremely difficult to keep in an aquarium unless you are very knowledgeable about their specific needs in terms of food and water chemistry. They are also the world’s greatest escape artists, seeming to stop only short of quantum tunnelling to get out of whatever container they are in, and that’s only because they haven’t figured out how… yet. Cephalopods are researching that one even as we type.

    So in answer to Greg… “yes” except that in the gaseous atmosphere of your living room, they don’t get very far.

  15. Steff Z says

    Ivan, one of the 2 Giant Pacific Octopuses on display at the Seattle Aquarium, has been checking out the gasesous atmosphere a bit these days. Last time I was there (last week), he was occasionally hanging out at the water’s surface, sending 2 or 3 arms up the side of the tank above him, and checking over the edge with the last ~10 cm of one arm.
    The top of the plexiglass is about 60 cm above the top of the water (and about 2.5 m above the outside floor), so when he starts pulling himself out, his mantle (the big bag of internal organs — like your torso) starts to leave the water before very much of his arms are over the edge, and he decides against it:

    Yuk! all that *gravity*, and so little buoyancy countering it. Never mind.

    When the display first opened a few years ago, the Aquari-nauts had to drop the water level another ~20 cm below what they’d planned, because the octos were deciding that that little adventure was worth it.
    (One staff member told me about standing under one of those early octos, arms over her head trying to push the octopod back in, and yelling for the octopus-biologist to come help.)

    However, Ivan is big: 12 to 15 kg, >2m arm-tip-to-opposite-arm-tip, and still growing . . . he may soon have a lot more than 10 cm over the wall, while staying comfortably wet.
    I’m picturing (in my over-dramatic but ever-hopeful imagination) tousled hair, stolen eyeglasses, and sucker-hickies on innocent visitors who thought they were just walking by.
    (Just kidding. Sucker-hickies from *octopuses* take a lot of doing. Just don’t let a *squid* latch on: their suctions cups have jagged, toothy calcified edges.)

  16. says

    Ivan, one of the 2 Giant Pacific Octopuses on display at the Seattle Aquarium, has been checking out the gasesous atmosphere a bit these days….Yuk! all that *gravity*, and so little buoyancy countering it. Never mind.

    When they develop portable force fields, humanity is so doomed.

  17. Kenny says

    Spent a week in hospital when I was 11 after treading on one in a rock pool with no shoes. Gee it was only a little bite and lucky I was near a hospital.

  18. says

    Beachcombing as part of one of my university field trips one year, I stumbled across the strangest tracks in wet sand I had ever seen.

    Puzzling as to whatever could have made such a chaotic tangle I turned to follow them down towards the water and discovered a large octopus hurridly trying to catch up with the retreating tide.

    (the two i discovered in flagrente delicto a few minutes later weren’t very happy about the plummeting water-levels either)

    There’s also an octopus in the Great Barrier Reef that comes out onto the beach at night to hunt crabs.