…and this is a 
Friday Cephalopod: Septopus!
Category: Cephalopods • Organisms
Posted on: September 8, 2006 8:13 AM, by PZ Myers
Go ahead, count 'em. Since there were some comments about octopuses with an odd number of arms, here's an example. Males of this species have a highly modified arm (the one they use for sex) that is tucked away in a pouch, so they have the appearance of a seven-armed octopus.
Haliphron antlanticus, the seven-arm octopus
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
Comments
How interesting.
Is it a pelagic octopus?
Posted by: Stanton | September 8, 2006 8:25 AM
PZ, are you by any chance a fan of Brendon Small's wonderful animated series Home Movies?
If you don't recognize the reference, go to this URL and search on "Septopus"! (The episode didn't get the best reviews, but I personally love 'em all.)
http://www.toonzone.net/homemovies/HeartSmashers.htm
Posted by: Julie Stahlhut | September 8, 2006 9:39 AM
I'm also a huge fan of Home movies and was startled to see "Septopus" coming from my Pharyngula RSS feed!
PZ, you simply must watch this episode that deals with the pie eating Septopus. :)
Cheers!
Posted by: O.B. | September 8, 2006 9:53 AM
Hmmm....an arm specially adapted for sex?
Sounds like a happily married octopus.
Posted by: phototaxi | September 8, 2006 11:09 AM
Octopus is originally from the Greek, isn't it? Shouldn't it therefore be heptopus?
Posted by: Prof. Bleen | September 8, 2006 11:58 AM
The Septopus episode was awful, but yeah, hooray for real septopi.
Posted by: Rey Fox | September 8, 2006 12:25 PM
Bleen said:
Yup.
Posted by: MartÃn Pereyra | September 8, 2006 1:03 PM
It looks like pretty good 7-way symmetry (don't know the technical term) - so where is he hiding the sex arm? I don't see a fold or crease in the web, and I can't see the pouch he's keeping it in.
Posted by: TheBrummell | September 8, 2006 1:11 PM
hey! "the heart smashers" episode of home movies, a.k.a. the septopus episode, was MARVELOUS! coach mcguirk blows out his pecs, and we get a glimpse into jason's darker side ask the group contemplates "getting rid of" paula's would-be boyfriend. and melissa's movie costume is to-die for!
note: the ballad of the septopus (theme music) is on the bonus CD that comes with the season 4 dvd set: a must have for all home movies devotees.
Posted by: Judy L. | September 8, 2006 1:41 PM
It's a wonder my trusty right arm could be seen at all then, after the teenagerdom I endured!
Fortunately, things improved...
Posted by: Steviepinhead | September 8, 2006 2:45 PM
Could the pentalateral symmetry of some echinoderms have evolved in a similar way?
Posted by: DAS | September 8, 2006 3:25 PM
Anyone remember Babylon 5? The Centauri were purported to have six penises, which were prehensile as well as rather long. (Londo Mollari was caught using one of his to cheat at cards.)
No idea whether they kept 'em in a pouch or not, though.
Posted by: Warren | September 8, 2006 4:01 PM
An octopus keeping one of its arms safe for best (ie sex) reminds me of a Red Dwarf episode: in which Lister gets infected (with the "Epideme" virus) and they have to amputate what he describes as his favourite arm (the one with which he does all his favourite things) to save his life.
Posted by: SEF | September 8, 2006 5:06 PM
Wow, a thread that encompasses two of my fave shows -- Home Movies and Red Dwarf!
Posted by: Julie Stahlhut | September 8, 2006 9:11 PM