flamboyant cuttlefish has two hectocotylus and uses them for hunting?

Discussion in 'Physiology and Biology' started by Polpessa, Sep 20, 2014.

  1. Polpessa

    Polpessa Cuttlefish Registered

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    Hi all,
    I was reading the 29:7/2014 issue of Ocean Geographic, and came upon an article about diving Lembeh Strait where the author describes the flamboyant cuttlefish (Metasepia pfefferi) as follows:
    "They have eight legs and two hectocotylus tentacles, which are twice as long and these are used for feeding and mating."
    The article then goes on to describe the hunting technique:
    "First, they extend their long feeding tentacles towards their prey. Seemingly taking aim and judging the distance of the strike. Next, the hectocotylus is fully retracted. Then, they strike with full speed."
    Is this true? I thought that the flamboyant has one modified left ventral arm as the hectocotylus (not two) and that it has nothing to do with the two feeding tentacles?
    Thanks for your help...:smile:
     
  2. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    I think the author has totally confused hectocotylus with tentacle. Is the article on-line somewhere? I could not find it using their search feature.
     
  3. Polpessa

    Polpessa Cuttlefish Registered

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    Thanks for your reply, DWhatley.
    If you go to this link
    http://www.ogsociety.org/
    you'll see, on the upper right hand part of the screen, a miniature icon of the current issue of the magazine, it has a shark on the cover outlined in orange with "Plights of our Ocean" written on it. Under that it says "Sign Up Now" and I think if you sign up for free membership you can download the current edition of the magazine for free. The article I am referring to is in the current edition so you should be able to see it that way if you download it now before the next edition comes out.

    So, just to confirm, the article is wrong, and the flamboyant has just one hectocotylus, the modified left ventral arm, and this has nothing to do with the 2 feeding tentacles, right?
     
  4. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Unfortunately the "O" edition seems to end at page 71 (I tried both the on-line magazine and the download), the Lembah article is on page 73 (I am assuming this is the article tagged as A Marine Naturalist in the PDF but labeled A Naturalist in Lembeh in the TOC). I am not sure if the "O" edition is intentionally shortened of if this is an oversite since the PDF TOC has a nonfunctioning link).

    I have read of squid having two hectocotyli and of the occasional odd individual octopus so it does occur but I have not seen this mentioned about Metasepia pfefferi , however, I have never kept them so one of our biologists would need to confirm.

    Here is a video taken by @Thales for the California Acadamy of Sciences. Watch closely at 1 minute to see the arms being used for spermatophore transfer. Our software will not accept the time parameter but you can use this directly to skip the first minute
    Code:
    http://youtu.be/SjLapY8mPI4?t=1m
     
  5. Polpessa

    Polpessa Cuttlefish Registered

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    Thanks again for your reply!
    When I signed up for the free membership unfortunately I was not able to access the article on Lembeh. I think for full access to the whole magazine you need to pay. :sad: Anyway the part I was questioning was the sentences I quoted in my original post. So it looks like I might need to contact a Metasepia specialist for a definitive answer?
    Thanks for the video btw, that's cool! I've actually been lucky enough to witness flamboyant cuttlefish mating in the wild during dives but that wasn't really enough for me to determine which arm(s) were being used, it was so quick! :bugout:
     
  6. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    I feel quite certain that the tentacles are not used for mating because this would be so unusual that it would be referenced. Single or dual hectocotylized arms however, has a slight possibility. I truely think the article is way off base and is why I wanted to read it and check out the author's background. I suspect journalist and not scientist.
     
  7. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Well, not jounalist. He appears to be mostly self taught with an undergraduate degree in zoology (not marine biology). He give lectures about the ocean that includes 5 dives. He definitely has tentacles and hectocotyli confused as to function in all cuttlefish. Here is a page on his website. Note the cuttlefish paragraph.

    http://mikescotlandscuba.com/cephalopods.html
     
    Last edited: Sep 21, 2014
    tonmo likes this.
  8. Polpessa

    Polpessa Cuttlefish Registered

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    I'm surprised someone with an undergrad degree in zoology would carelessly make such incorrect statements without doing some research first. He also spells flamboyant as "Flambuoyant" on his website. I'm even more surprised that Ocean Geographic would print this stuff. He also had a variation on this article written about his trip to Lembeh published in an online dive magazine here:
    http://www.depthmagazine.net/Magazines/May_June_2014/index.html
    in which he happily describes how his dive guide moves, pokes, and feeds all manner of creatures so that he can get his shots; it's shameful and gives absolutely the wrong impression about diving and photography. Again, I can't believe the editors printed it!
     
  9. tonmo

    tonmo Titanites Staff Member Webmaster Moderator

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    :lol: this thread makes my day. o_O
     
  10. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    LOL, now you know why I wanted to read the article. The problem we have with cephs is common with a lot of things in that unbelievable physical attributes can often be true or misunderstood hearsay. Even finding out about the author's qualifications may not validate or negate what we think we know (the correct but dismissed findings of the colonial living, beak to beak mating and multiple broods of the Greater Pacific Striped octopus come to mind). I rely a lot on Wikipedia for quick basic knowledge of unfamiliar subjects but not detailed information (sometimes the cited works are a good starting place though). The article on Metasepia pfefferi is quite good and does mention the hectocotylus is a modified arm (stating left ventral) however if my guess is correct on the video, and if it is typical of octopuses, the mention of it being on the left is in question. The article fails to specify which arm (dorsal does not clarify). The general cuttlefish article, includes material that is incorrect
    or may only be true of only a few species
    So often one article is written and then copied over and over, making it difficult to find the original source and validation becomes almost impossible.
     
    Last edited: Sep 27, 2014
  11. Polpessa

    Polpessa Cuttlefish Registered

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    Does this thread "make your day" (I keep hearing it in Clint's voice!) because of my naivety in thinking editors should check what they publish or because you find it funny that someone who studied zoology would write what he did about the flamboyant cuttlefish?

    I also asked Bret Grasse who raises flambos at the Monterey Bay Aquarium and he said this:

    "Your assumptions are correct. Flamboyant cuttlefish have a single hectocotylus (modified arm) that is completely unrelated to their two feeding tentacles. It is not used in any way during hunting. The hectocotylus looks nearly identical to the other arms except it has a fine grove running along its center laterally. 8 arms 2 feeding tentacles."
    D Whatley, you made very good points about both the nature of online material and new research.

    Now I'm curious to know if the hectocotylus is indeed the left ventral arm or not, I will look at some footage we have here to see if I can tell from that.
     
  12. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    @Polpessa, you have me intrigued by some of the things I found and wondered how they could possibly have been written as fact. I did figure out the basic source of the females only have three (or a total of 6 instead of 8) arms. Dr. Hanlon was quoted in an article (referring to the Australian giant cuttlefish) that the females lack two of the flattened arms. The intended meaning was to point out sexual dimorphism and that the two of the male arms are wider and flatter, not that the female had two less. The Wikipidea article used a version of that interview to write the entry and misunderstood the statement.

    It gets worse :roll: http://en.wikipedia.org/wiki/Hectocotylus shows squid tentacles as hectocotyli in a diagram. It also has a list of referring to different species and says,
    Arms 4 are the back most arms as numbering begins at the eyes.

    From the same article, tThis is also suspect (referring to the paper nautilus)
    It is getting harder to blame a self study author.

    @Tintenfisch - you can chime in at any time :sagrin:
     
    Last edited: Sep 27, 2014
  13. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    So off on a rabbit trail it occurred to me to use the FAO catalog I have in PDF form to see what it shows. Under cuttlefish and squid it does indeed show the hectocotylus as arm L4 but confirms the only animal I think I know something about (octopuses) as generally being R3 (whew!)
     

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  14. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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  15. tonmo

    tonmo Titanites Staff Member Webmaster Moderator

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    that's the one! That, combined with the absurdity of the error. :razz: As for this:
    I have fallen for this many, many times. It's a bit embarrassing when I tweet or post something on FB on behalf of TONMO only to find that the "news" I was sharing was incorrect / not properly researched. :oops::oopsie:
     

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