Mercatoris Musing

Discussion in 'Octopus Care' started by ekocak, Apr 24, 2015.

  1. ekocak

    ekocak Vampyroteuthis Registered

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    The very first octopus I had, in high school, probably about the year 2000 looked very much like all the pictures I'm seeing in the gallery of Mercatoris. It was sold to me as a vulgaris. Were they being imported back then? I wish I had any pics, but this was pre-everyone having a digital camera days. The color and shape and size seem about right. It was also extremely secretive and shy compared to the bimac I had later.
     
  2. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    If you think about it, consider adding at least the country to your profile so it will show on your posts, it really helps with some of the questions, especially out of the US. Since you have also had a bimac, I am assuming you live in the US but correct me if that is erroneous :grin:.

    Mercs have been the most common Gulf and US southern East Coast dwarf since we have records. They have a long time history of being mislabeled as O. joubini and only fairly recently has it been clearly established that there are at least two common dwarf species in this area (I have kept a third and still have no idea what species Monty was - absolutely sure he was neither a merc or a joubini) and may have kept another that highly favors O. hummelincki (a whole can of worms on the naming of this one. At one time it was considered a dwarf but has since been classified as a medium sized animal - quite a wide range of sizes has been recorded). The major identity difference between O. mercatoris (and there is some question on the actual proper name for this one) and O. joubini has been the egg size and number (O. mercatoris has large eggs where O. joubini is a small egg species). There was a nice 1991 write up done on O. joubini that is in the species forum but there are no photos and I never received a reply when I requested more info. I have yet to see one personally and have not found definitive photos so am in a bit of a quandary on how similar they are (the paper suggest they are not hard to distinguish). O. joubini has been mistaken for juvenile O. vulgaris for a long time but most vendors really have no clue what to look for to give the animal an id. The vendors can't really be blamed though as not only is good information hard to come by, many octopuses are very hard to ID as juveniles and all have similar characteristics they can display.
     
    Last edited: Apr 25, 2015
  3. ekocak

    ekocak Vampyroteuthis Registered

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    Profile updated! If I recall correctly, the 1st octo was labeled as "Atlantic" on the shipping list and sold in the shop as "vulgaris" so it really could've been anything. As a teenager I worked in a marine aquarium shop which is why I remember what it shipped as. Probably won't ever know, but it struck me as I was looking at everyone's photos that I probably had it wrong all these years, and that may have been a good thing, since it was in way too small of a tank for a vulgaris.
     
  4. tonmo

    tonmo Titanites Staff Member Webmaster Moderator

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    Yeah, I think vulgaris is typically quite a bit larger than mercs when full grown, although mercs are generally a large species for a home tank... I wouldn't think you'd want to go much larger than that in a hobby tank! Since O. vulgaris is typically known as the "common octopus," it seems many LFS will just go with that label. ("Well, gee, it's common, so chances are good that's the right label!" :smile:)

    You know what we need? A "Commonly Kept Octopus Size Comparison Chart," complete with general guidance on accompanying tank size. Any volunteers? :heee:
     
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  5. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    I worked up this post in 2013 and included it along with a few other discussion in the Posts with Infor for New Octopus keepers sticky. The post is not quite a chart but gives some basic info on the animals we most commonly see.

    Edited by TONMO: changed URL to https
     
    Last edited by a moderator: May 10, 2015
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  6. tonmo

    tonmo Titanites Staff Member Webmaster Moderator

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    This is a great one! I even Liked it, apparently :smile2: I may convert that to an article... we should probably do that with a bunch of your best posts :thumbsup:

    :feet:
    (note my edit to your post above... if you use a bookmark for TONMO, please change it to https... I haven't been able to get htaccess to handle this properly!)
     

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