The Octopuses Have Landed

Discussion in 'Cephalopod Journals' started by Spocktopus, Jun 22, 2006.

  1. Spocktopus

    Spocktopus O. bimaculoides Registered

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    Hi everyone. Some of you may know, I am a student at the University of New England, and I am doing the preliminary work for a reasearch project regarding octopus behavior over the summer. The actual data trials are scheduled to take place during school in the fall. I am hoping to study learning and memory as it relates to fine tactile discriminations, and then how that compares with visual performances. I also hope to perhaps shed a bit more light on what basis octopuses discriminate texture, and can they remember a specific grade of roughness as a positive target? Or do they remember soley rougher vs. smoother?

    Anyway, I just got in three O. bimaculoides. I will post some preliminary pics when I get some time. They arrived two days ago and are alive and happy in their tanks. They have yet to be named, but I'm seriously considering going with a Pac Man theme...#1 definitely has to be Blinky because he's the most active and tries to cause the most trouble when I'm changing the water in his tank.

    I've just started observing them over the past couple of days as I work to get a testing system ready for the actual experiment. I will post more details later, but right now I have a question:

    I know double signaling has been shown in squid and cuttlefish in mating situations, but has it been shown in octopus? Mine have been flashing a brief display in which they make half of their body very dark, and then slowly fade it to match the other half. It's like a line drawn between their eyes, starting out very distinct. Does anyone know anything about this particular display?

    I am very interested in color change and how it is used for crypsis vs. communication in cephalopods, and how this sort of "signal language" compares between cephalopod groups. If anyone knows any good info sources or research facilities for this subject, I would love to know. Thanks.
     
  2. monty

    monty Colossal Squid Staff Member Supporter

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    I don't know specifically about it behaviorally, but the first thing I thought of when I read this was the picture in Hanlon & Messenger box 5.1 (p.71) that shows an octo whose chromatophores are denervated on one side of the mantle, which suggests, on sort of a gross physiology level, that the two sides are separate functional units for color change, perhaps. It says it's Eledone cirrhosa, but I imagine that extends to Octopuses in general. There are a lot of references listed in Hanlon and Messenger (start on p.39, maybe); I'd recommend starting from there and using google scholar to look for articles that reference those...
     

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