Potential Evolutionary Path of Metasepia

Discussion in 'Physiology and Biology' started by Phil1078, Aug 25, 2010.

  1. Phil1078

    Phil1078 Blue Ring Registered

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    So Mr. Ross' flamboyant cuttlefish got me thinking. In Metasepia we really get a glimpse of some of the environmental pressures that lead to the octopus. If I am not mistaken, the cuttlebone is greatly reduced. Metasepia is supposed to tire of swimming more easily. There is also an adaption to walking. Now what I find really interesting on this new take on the octopus' way of life are the little stalks or papillae (I am not sure what to call them) that are located on the ventral side of Metasepia's mantle. Could this eventually lead to a 12 legged octopus-like cephalopod? The muscular, mollusc foot evolved into legs, so perhaps the mantle will too. It seems analogous to the "thumb" of pandas, which is really a separate hand bone (I believe the sesmoid). Anyway, I am not the most well versed in cephalopod evolution, so please correct me if my speculation is way off.
     
  2. cuttlegirl

    cuttlegirl Colossal Squid Supporter Registered

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    I so wish Monty were still around to answer this one... Development of the arms occurs from the same group of embryonic cells in cephalopods - I have an article that I will try and find... - so the papillae will not evolve into more legs.
     
  3. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    CG, when I saw the question, I thought the same thing.
     
  4. kpage

    kpage Wonderpus Supporter

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    wow... I just read what happened to Monty... Must have missed it because of my job. That's terrible.

    sorry to detrack the thread
     
  5. cuttlegirl

    cuttlegirl Colossal Squid Supporter Registered

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    Ok, here's the title of the paper...
    I have the full paper, but it is not for redistribution, but if you are a biologist and interested, I will find a way... PM me. It is a really complex paper, I will try to summarize it after I re-read it...
     
  6. Stavros

    Stavros GPO Registered

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    I like the fact that Cousteau was saying this back then.

    Octopus and squid, the soft intelligence
    JY Cousteau, P Diolé - 1973 - Doubleday Books
     
  7. Level_Head

    Level_Head Vampyroteuthis Registered

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    Hmm. I'm not sure that it's a question of papillae evolving into more legs. The flamboyant seems to walk on muscular extensions of the mantle. I had at first though that these were modified swimming fins, but the fins are still present (though very diaphanous) and still used for swimming.

    The walking process uses muscles, not just the apparently more "passive" extension of the skin protrusions. It would be interesting to see a diagram of the ventral mantle musculature of this creature.

    I'd be inclined to agree with Phil1078; this development does seem to be walking the path, so to speak, of a different mode of locomotion.

    It's interesting to me that the flamboyant cuttlefish seems best equipped of all the cephalopods to stride out onto land. Those muscular protrusions are seemingly steerable, stretchable and flexible (though they obviously don't have to bear much weight in his current environment) -- it would be intriguing to see where evolution could take this animal.

    I can picture a sort of quadruped stance based on extensions of the mantle, short and sturdy, with all of the current arms and tentacles available for food capture and perhaps, eventually, tool-building. Every "land based cephalopod" concept I've seen had them walking on the arms, though often with some specialization. This is a new possibility.

    Are there any other cephalopods with this sort of pseudo-articulated mantle musculature?
     
  8. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    ... or could it be that they never developed the swimming structures of their cousins and the "leg" fins are remenents of land life?
     
  9. Level_Head

    Level_Head Vampyroteuthis Registered

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    I don't know -- that loss of functionality is not easy to definned.

    Hmm. The occasional above-water excursions by octopuses work as long as their gills are kept wet, I understand. There is another creature that emerged from the sea long ago but now is entirely terrestrial, and it too must keep its breathing apparatus wet: the spider. They use "book lungs" with openings underneath, and they've evolved elaborate mechanisms (especially the desert types) to keep those surfaces moist.

    Perhaps our cephalopods might do something like this.

    Hey, a genetic researcher who specialized in manipulating genes to create new cephalopod body parts for operating above water -- would she be an octogenairian?
     
  10. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    "D" Grabs silver cross and runs backward emphatically saying, no, no, no

    I just read at least one articles about whales having been land animals as evidenced by fossils and don't remember the source (likely started with something here) but here is a quick summary of the findings

    The significant difference would be that whales remained lunged air breathers with modified intake and exhaust. It does not take much to envision this guy trundling about on land but I have no idea if we have seen gilled animals in a reverse engineered evolution.
     
  11. OB

    OB Colossal Squid Staff Member Moderator

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    Sepia bandensis appears to be halfway there, for one...

     
  12. Phil1078

    Phil1078 Blue Ring Registered

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    When I was referring to papillae becoming legs, I really was referring to the muscular extensions under the mantle. I just didn't know the terminology for it.

    I believe you are referring to tagmata cuttlegirl, or at least a similar word. I learned about that in my insect class. It is a good point, but I think different tagmata can be modified given enough evolutionary time.

    Level head makes a good point about Metasepia being able to invade land. I can definitely picture a "quadruped" cuttle ambushing insects and small verts.

    Ob, thanks for the biped cuttle post. One can see pretty easily the bouyancy of the cuttlebone. It is keeping that mantle pretty level. In Metasepia, with its reduced cuttlebone, the muscular mantle extensions are a must in order to keep it from dragging the mantle all over the place. Great video.
     
  13. cuttlegirl

    cuttlegirl Colossal Squid Supporter Registered

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  14. Phil1078

    Phil1078 Blue Ring Registered

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    I actually read the Pharyngula post last year when I did as research paper on the Deimatic Display in Sepioteuthis sepioidea answering the four behavioral ecology questions of adaption, physiology, ontogeny, and phylogeny.

    The article notwithstanding, I still do not think it is too much of a stretch to see the muscular mantle extensions in Metasepia being used for more intense locomotion.
     
  15. Level_Head

    Level_Head Vampyroteuthis Registered

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    I may borrow this notion for Book 3. Not to give away a spoiler...
     
  16. perke

    perke O. bimaculoides Registered

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    Sepia officinalis when in a smaller stag of around 2-3cm mantle will also display this walking ability. I've been working with Metasepia for around 5 months and they vary in their strategies. Sometimes they will swim, sometimes they will use their mantle for walking along with arms and sometimes just their arms similar to bandensis. The locomotion with the mantle extensions are rather slow and from what i've seen is more when they are stalking something such as a shrimp.
     
  17. Thales

    Thales Colossal Squid Staff Member Moderator

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    +1

    On a related note, I don't think they are particularly bad swimmers as is sometimes thought.
    Have you noticed anything regarding the floating issue with these guys?
     
  18. perke

    perke O. bimaculoides Registered

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    No they swim just fine, they have a tendency to float at the surface when they want something such as food, but this is not uncommon in officinalis if you don't feed them enough. They actually spend a lot more time swimming than I originally thought they would. When there is activity around the tank and something interesting going on they will actively come off the sand to check it out. In fact they have some very interesting postures that they can do with one another where one is on the sand and the other hovering mid water column.
     
  19. Thales

    Thales Colossal Squid Staff Member Moderator

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    Great stuff.

    I am noticing that they get 'floaty' sometimes and seem to get uninterested in eating. Very strange. The hovering towards each other sounds like breeding posturing.

    Can you tell me about how you are keeping them? What size tanks, how many per tank and such?

    Thanks!
     

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