Compare,contrast,and scale hombolt beak to giant/colossal squid.[Does not scale,why?

Discussion in 'Physiology and Biology' started by scottwolverine1, Jan 7, 2008.

  1. scottwolverine1

    scottwolverine1 Pygmy Octopus Registered

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    This is my first post,so bare with me.
    -Why is the little 50-150 pound hombolt squid's beak nearly the size of the 10 time larger colossal squids?
    -Perhaps I'm underestimating it,if so please inform me as such.
    -If I'm not underestimating it,then are there any therories on why,like evolutionary reasons,prey item selection,or something like that.
    Finally,how do I show my support for the banning of deep sea bottom trolling.The world needs to be aware of this and what its doing to the marine life.
     
  2. monty

    monty Colossal Squid Staff Member Supporter

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    Good question, and I'm not really sure what the answer is, but I'll take a crack at it.

    From the size of beaks Steve O brought to TONMOCON it looked like the colossal squid beaks were considerably bigger (around 3 or 4 times larger) than the humboldt squids, and remember that weight scales as the cube of length, all other proportions being equal, so if the beak is 3 times as long, one would expect the weight to be about 27 times as much. But I think you're right that they're out of proportion a bit: they're more in proportion to the size of the prey than the size of the squid. The size of a colossal squid's prey (Patagonian toothfish) is not so much larger than the largest prey items of the humboldts. Also, seeing the preserved humboldt and giant squids side-by-side at Mote really illustrates how much more muscular and well-armed the humboldt is for its size... they're well suited to going after big prey, and they hunt in packs.

    On the flip side of that, cephalopods pretty much have to take small bites: a cephalopod's esophagus passes through the middle of its donut-shaped brain, so if it takes too big a bite, it could literally cause brain damage, so there's a not much benefit in growing the beak any larger than the brain. They seem to be very good at strategically using their beaks, both to inject venom and find chinks in the armor of crustaceans, since ancient cephs pre-date fish so they probably primarily ate crustaceans and trilobites. More recent cephs seem to be able to quickly disable vertebrates, too, as in the "octopus vs. shark" video that's around a lot (it's probably on youtube) where it looks like the octo knows it can disable the shark by biting its spine, although it may just have broken the spine by arm strength. Squids seem to favor repeated rapid biting, but really, by the time a prey animal has been pulled from the tentacles to the arms, it's pretty much immobilized, so the squid doesn't have to kill it quickly with the beak. As far as I know, squids don't have toxins that disable vertebrates like fish, but most cephs that prey on crustaceans have cephalotoxin that disables them quickly, too... I assume squids catching fish pretty much can just hold them in their arms and take bites as they want, and there's not much a fish can do, although there might be other ways squids kill or disable their prey rapidly.

    So I guess my bottom line guess at the answer is that unlike the jaws of a shark, the squid's beak isn't really its primary attack weapon: the tentacles and arms handle the capture and subdual of the prey, so the beak just has to be big enough to bite into the prey and get to the tasty parts.
     
  3. scottwolverine1

    scottwolverine1 Pygmy Octopus Registered

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    Monty,
    Thank you very much.
    -Its a good feeling to "suddenly" be more informed/educated.
    -Now,if we can do something about those "deep sea/bottom nets causing havoc and destruction,the rest of the world will become more informed, and amazed, by these amazing creatures.
     
  4. Spence24

    Spence24 GPO Registered

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    Well :welcome: to tonmo... I really can't help you with any of that Sorry.
     
  5. monty

    monty Colossal Squid Staff Member Supporter

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    I'm glad it was interesting... but take it with a big grain of salt until someone like Steve or Tintenfisch responds, since they've actually got hands-on experience with this sort of thing...
     
  6. Steve O'Shea

    Steve O'Shea Colossal Squid Supporter

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    The size of a mature Mesonychoteuthis beak leaves that of the Humboldt for dead, honestly!

    It is one of those questions that I have asked myself many times. Basically you cannot use mantle or total length to predict beak size. There's a squid here, Idioteuthis cordiformis (often referred to Mastigoteuthis), that has a massive beak relative to the size of the animal - almost as impressive as that of the considerably larger and heavier Architeuthis. The amazing thing about Idioteuthis is that we don't know what it eats; its stomach almost invariably is full of oil, we've not found a single bone or scale in there, and similar species are thought to eat relatively tiny planktonic crustaceans (like Asperoteuthis does .... although I'm writing something that is not my research, and has yet to be published, so I cannot give too much away).

    One of these days someone will come along and want to look at the relationship between beak and palatine tooth morphology, and diet, and relate this to aspects of the total squid morphology. It would be an amazing bit of research!
     
  7. Tintenfisch

    Tintenfisch Architeuthis Staff Member Moderator

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    I'm not taking the bait this time!! :bugout:
     
  8. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    What? No post-doc, post nuptual excitment planned?
     
  9. Tintenfisch

    Tintenfisch Architeuthis Staff Member Moderator

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    All going to plan, post-doc somewhere for sure, but probably not on palatine tooth morphology - I believe SOS has sinister plans to unleash that project on another hapless PhD student. :roll:
     
  10. scottwolverine1

    scottwolverine1 Pygmy Octopus Registered

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    If I were a graduate student,I would run with it.
    -Potential finds would be interesting to both the academic and public worlds.
     

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