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    How To Tell Two Squid Apart
    By Danna Staaf | June 4th 2012 03:09 PM | 5 comments | Print | E-mail | Track Comments
    About Danna

    Cephalopods have been rocking my world since I was in grade school. I pursued them through a BA in marine biology at the University of California...

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    Dear squid blog, I am sorry that so many other projects have been keeping me from you lately! My love for squid remains undimmed. Just to prove it, I will share with the world a helpful chart that I drew several years ago and recently unearthed.

    The Humboldt squid (Dosidicus gigas) and the purpleback flying squid (Sthenoteuthis oualaniensis) can look very similar. If you're fishing in a location where only one of them lives (like Indonesia for Sthenoteuthis or California for Dosidicus), no problem. But in certain areas of the Pacific Ocean--oh look I have a map--their ranges overlap, so there is confusion. Panic. Mayhem. Which squid is it?


    But never fear, you too can become a squid expert in three easy steps! Here's the cheat sheet:




    In words: if the squid has a big photophore on its back, it is definitely Sthenoteuthis. But if it doesn't have a photophore, you can't be sure, and you have to move on to the next two items. If the skin slips and slides and bunches up easily, then it's Dosidicus. If you can't budge the skin, it's Sthenoteuthis.

    Finally, if you're doing a dissection, see whether you can separate the mantle from the funnel with your hand (Dosidicus) or if you need a knife (Sthenoteuthis).

    There now, don't you feel better?

    Comments

    Bonny Bonobo alias Brat
    If the skin slips and slides and bunches up easily, then it's Dosidicus. If you can't budge the skin, it's Sthenoteuthis
    What if its an old squid?

    Make love not war
    Danna Staaf
    As far as I know, humans are the only animals whose skin grows loose and wrinkly with age! Isn't that curious?
    Aging squid of many species do end up with thinner mantles, as the muscle breaks down to provide energy for spawning. But the skin doesn't get any looser.
    Bonny Bonobo alias Brat
    As far as I know, humans are the only animals whose skin grows loose and wrinkly with age! Isn't that curious? 
    Yes, and its also rather depressing when you get to my age!
    Make love not war
    Great, next time I am swimming in the Pacific, I will grab their skin to determine if they are Humboldt eying me as a meal. Or is just the fact that they are within reach enough to tell me I am in trouble? ;-)

    Danna Staaf
    Hah! That would be a great use for this guide; I would be well pleased.
    In all seriousness, I know a number of scientific divers who've interacted with Humboldts underwater and had a totally pacific (heh heh see what I did there) experience--mere curious exploration. But that doesn't obviate the fact that they should be treated with the same caution as all wild animals, especially predators.