Slug love


Some of you may recall a movie of mating slugs I mentioned before…now here’s a site with photos of the act.

In case you’re baffled, the strange translucent blue sheets hanging down are the interwined penises of the two slugs. Don’t they make a beautiful couple?

(Thanks, Craig Clarke! Does your mother know you browse the web for molluscan porn?)


  1. Bat-Cheva says

    Well. Those are rather, ummm, impressive.

    And I’m not at all sure I’ll ever get the image out of my mind.

  2. scolex says

    This post reminded me of this comic.
    Granted they’re snails instead of slugs, but the humor remains the same.

  3. Owlmirror says

    I just scrolled down to the customer reviews for Life in the Undergrowth, and I see that there is one single one-star review among the glowing five-star reviews. This one person was “very disappointed” with the DVDs because “They were FULL of evolution”.


  4. CCC says

    I actually stumbled on that by accident, but my mom knows I enjoy looking for molluscs. They have nice big ones where I live. I have a 14 inch Lighning Whelk shell on my porch table.

  5. JohnJB says

    Now, I love a big transluscent blue penis as much as the next guy (probably more so), but as I understand it, the organ coming out these critters heads exchanges both eggs and sperm.

    So the term penis isn’t quite right , is it?

  6. says

    Wait… the entire blue glob is their penes? And they come out of their heads? I have no idea if I’m seeing that right. And is it still “mating” if they’re both male?

  7. Owlmirror says

    And is it still “mating” if they’re both male?


    Some molluscs fence with their penes. Others shoot sperm darts into each other’s bodies. This is less ballistic and more balletic.

  8. says

    I’m moved to song:

    A twisted young fellow named Wallace
    Once had an affair with a mollusk,
    But that’s not as odd
    As the brachiopod
    Who buggered an ostritch for solace.

  9. Jeb says

    I can’t believe that the obvious hasn’t already been stated.

    Those slugs are hung!

  10. Paul Riddell says

    As with most visuals of this sort, I can hear Bill Hicks commenting on this:

    “You the guy buyin’ all the bobbin’ slimy slug-ass movies?”

    “Nuh UH! It said ‘Pink Gastropods’! If it had said ‘Bobbin’ Slimy Slug-Ass’, I never woulda bought the m**********er!”

  11. monstruoso says

    Ahh, so weird and pretty… once saw a slug in a neighbor’s yard that actually startled me, it was really big had these huge eye spots and.. and… well, it looked at me… shudder.

  12. JohnJB says

    The earlier post about the slug movie us titled
    They’re blue, and long, and prehensile, and beautiful!

    Which prompted the comment:
    Drop out the second “and” and it scans for the opening of The Girl from Ipanema.

    Which got me going:
    They’re blue and long, prehensile and beautiful,
    They hang on stands of mucus so fanciful,
    And when they twine, it feels so fine, they go ahhh…

    Slick and wet and oh, so clingy,
    I wish I had a pale blue thingy,
    And when they twine, it feels so fine, they go ahhh…

    Ooh, but I envy so madly,
    How can I ever aspire to ….
    Drat, do I do sex so badly,
    I can watch, and can love what I see,
    Slugs indeed do have more fun than me.

    They’re blue and long, prehensile and beautiful,
    They hang on stands of mucus so fanciful,
    And when they twine, it feels so fine, they go ahhh…

    They go ahhh …

  13. says

    Thank Owlmirror – the only hermaphrodites I know anything about the mating of is C. elegans, and from what I recall the more rare males can cross-mate with a hermaphrodite but otherwise the hermaphrodites self-fertilize internally.

    Taking off of JonJB’s comment… so is the sac at the end gametes? And since they’re hermaphrodites they have both and are just randomly exchanging? I imagine that afterwards they suck it all back in and later lay eggs?

  14. CCC says

    I’m surprised nobody made any “dickhead” jokes.

    And that “shooting sperm darts into each other’s bodies” thing gives me an idea for a macromedia flash game.

  15. Owlmirror says

    According to this biology lab page (search for “Courtship and Mating”), they are exchanging sperm only. Apparantly, they do sometimes self-fertilize.

    A mutual exchange of sperm occurs and the penes unwind and are retracted. […]

    The sperm are stored initially in the seminal receptacle but eventually make their way upstream to the fertilization chamber where fertilization probably occurs.

    There’s a more detailed description of the Limax reproductive system as well.

    There’s also this rather explicit description of the foreplay:

    During warm months pairs of sexually receptive individuals climb to some elevated position in a bush or tree and follow one another in a circle while licking each other for as much as 2½ hours. Eventually they entwine and drop from the perch and hang suspended, like amorous bungee jumpers, by a tough mucus strand that may be as much as 25 cm long

    Whoa, kinky.

    More pictures here:
    Leopard Slug Aerial mating

    and here:

    Leopard Slug, Limax maximus

  16. Scott Simmons says


    Oh, good. I was afraid maybe they were gay slugs.

    That would have been really gross.


  17. jv says

    I don’t know if anyone will ever read this, and if they do, I imagine they’ll wish they had not, but:

    When I was a kid (under 10, forget exactly), I was walking out my front porch and came across a couple of slugs just starting to hook-up. In retrospect (in human terms), I would say they’d had a good date, and at the end of the night one slug invited the other up for a “nightcap”, and they were just starting to make out on the couch.

    A curious child, I sat down to watch them (fighting off the initial urge to salt them — cruel, yes, but a disturbingly fascinating thing to see, as well). They anchored their slime belay and descended over the precipice, entangling in that little swirl thing they do and extended their “appendages”. Lots of goo and oozing.

    At the time, I was not entirely certain what they were doing, but I suppose I had a hunch.

    It certainly made the later “birds and the bees” talk far more psychologically devastating for my parents…

    Perhaps unrelated, but I’ve never been phased by any sexual fetishes as an adolescent or adult. I’m not into most of them, but still nothing really shocks you when your (internal) response is “well, that’s not as gross as the slugs”.