Garden Slugs Mating
Here is my personal contribution to the art of mating slugs.
These large slugs are common in my yard, but I have seen them mating
only this one time, and all I had handy was a video camera. So I
carefully and not too quickly panned along the length of the pair, then
put together this decent snapshot by stitching together a set of 3
Aside from bringing out a surprising beauty of these normally sort of
"blah" animals, the mating process of slugs will shake your
preconceptions (groan!) of how these things work.
These slugs have an elaborate ritual involving much crawling around
each other in circles, followed by twining together and hanging from a
cord of slime, and culminated by flaring together of large genitalia
that are extruded from underneath the mantle on one side of the
The slugs of this species are hermaphroditic, but must exchange sperm
in a symmetric act.
Other species do things a bit differently, including some that even
convert males to females by a process called "apophallation" -- biting
off the penis -- or so it says in one of the articles referenced below.
For more images and information on the biology, try some Google
searches on "mating slugs". A particularly good page is at http://www.arnobrosi.com/slugbio.html.
A set of excellent
pictures can be found at http://oregonstate.edu/Dept/nurspest/Limaxmaximuscourtship.htm.
Other good general information can be found at http://www.xerces.org/Wings/spring2003.htm.
A excellent video from BBC is currently posted at http://www.youtube.com/watch?v=CKPBCXdR6yo
The image on this page is from my archives, about 9 years old
is amazing how camera technology has matured in that time!
-- Rik Littlefield (contact me here)
Page last modified January 21, 2009.