Genetic Differences in Cephalopods

Discussion in 'Physiology and Biology' started by Level_Head, Oct 26, 2011.

  1. Level_Head

    Level_Head Vampyroteuthis Registered

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    This paper (free) talks about genetic differences between certain octopus species, particularly with respect to the one they're describing, O. insularis. It was very similar in appearance to the larger O. vulgaris, but turns out to be much further away in mitochondrial genes than expected:
    http://www.demersais.furg.br/Files/2008.Leite.O.Insularis.J.of.Molluscan.Studies.pdf - 2006

    The paper describes both the dorsal mantle white spots and arm crown spots in that species as distinct structures in common with O. vulgaris, but does not give much in the way of details.

    In the case of the research discussed, they work on the usual, mitochondrial percentage differences. And they note that this can produce odd results; they express a hope for studies done with octopus nuclear DNA instead.
     
  2. CaptFish

    CaptFish Colossal Squid Staff Member Moderator

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    Genetic Differences in Cephalopods

    A thread to discuss Genetic Differences in Cephalopods, and a place to post related material.
     
  3. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Thanks for the pdf reference Level_Head but not for the dorsal mantle white spot info :sagrin:. For whatever reason, I am determined to learn to ID our animals and when we have one that lives a normal life span unidentified it sticks in my mind. Penelope was one of these animals. I was sure it was not O.vulgaris because of the once seen ocellus and had guessed insularis. The paper gives a very good description of both the lines CaptFish saw AND the occassionally seen ocelli. Made my day!!

    I am also going to reference this paper in the species section and quote the mantle description in the ppost.
     
  4. Level_Head

    Level_Head Vampyroteuthis Registered

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    Oh, the point of that mention was to echo the thought that it was a common feature of a great many species. I wasn't trying to suggest a species ID, just learn a little more about the cellular construction of those spots.

    The paper had other interesting spots of its own, hence the post.
     
  5. Level_Head

    Level_Head Vampyroteuthis Registered

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    Oho! Do you think that Penelope was an insularis, then?
     
  6. CaptFish

    CaptFish Colossal Squid Staff Member Moderator

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    I don't. He was caught in the florida keys, and they are described as being from S.america. i am 99% convinced he was a vulgaris.
     
  7. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    I DID but ...
    After reading more of the paper and seeing several more confusing things (like both small and large eggs and both benthic and palegic young) I went back over the the PDF (sometimes books are easier) and realized that the amended description I was excited about was for the general vulgaris group and NOT insularis. Later in the paper it states there is no ocelli - bummed

    However, with the warming waters seeing a South American animal would not be surprising.
     
  8. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    GPO vs Rubescens

    The Seattle aquarium posted an article, Which Octopus Are You Seeing? to differentiate between Enteroctopus dofleini and Octopus Rubescens.

    The bullet points for Enteroctopus dofleini:
    Weight:

    Average 60lbs
    Up to 150lbs
    Arm Span:

    Up to 20 feet across
    Life Span:

    3-5 years
    Mating:

    Terminal maters, both male and female will die after mating.
    Female will lay 20,000 to 100,000 eggs and guard them till they hatch.
    Males have a modified 3rd right arm used in mating (lacks sucker disks at the end of the arm).
    Main Identifying Feature:

    Giant Pacific Octopuses do not have "eyelashes", paddle like projections under their eyes.
    Coloration:

    Giant Pacific Octopuses are more red in color.
    Skin Texture:

    Giant Pacific Octopuses have paddle-shaped skin projections.
    Common Den Types:

    Rock piles, under rock ledges, tires, under downed pilings, old pipes.
    Growth Rate:

    1-2% of their body weight every day! Human example: gaining 2-4lbs a day.
    Largest species of octopus in the world.


    The bullet points for Enteroctopus dofleini:
    Weight:

    Max of 1.5lbs
    Arm Span:

    Up to 20 inches across
    Life Span:

    2 years
    Mating:

    Terminal maters, both male and female will die after mating.
    Female will lay 20,000 to 30,000 eggs and guard them till they hatch.
    Males have a modified 3rd right arm used in mating (lacks sucker disks at the end of the arm).
    Main Identifying Feature:

    Reds have "eyelashes" - three paddle like projections under their eyes called papillae (click here to see a picture).Coloration:

    Reds are more brown/grey in color.
    Skin Texture:

    Reds have rounded skin projections.
    Common Den Types:

    Bottles, old barnacles, moon snail shells, under downed pilings.
     
  9. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    A neurophylogenetic approach provides new insight to the evolution of Scaphopoda
    Lauren H. Sumner-Rooney,Michael Schrödl,Eva Lodde-Bensch,David R. Lindberg, Martin Heß,
    Gerard P. Brennan,Julia D. Sigwart 2015 (subscription)

    [DWhatley] Interesting abstract proposing to add the scaphopods mollusca to the cephalopod grouping (genus?)

     

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