GASTROPODA!

In my last post, I mentioned the darker-skinned Apple Snails. This isn't the darkest one, but she's the one I could find today.  (I say "she" because I saw her laying eggs. They're not hermaphroditic.) One online aquarium stuff supplier is selling these as just "Black Apple Snails" or "Mystery Snails." My guess is that they're the same creature with dark skin or light.

And, no, this is not the actor who played Davy Jones in Pirates of the Carribean. (She gets that all the time.) They cast a look-alike for that role, someone who could work longer out of water without drying up.

Above: Size comparison. Apple Snail versus Ramshorn Snail. 

At night, these Ramshorn Snails are absolutely everywhere. They don't seem to eat that voraciously, so it's no big deal. A super-neat thing about them is that they can crawl on the underside of the water's surface without breaking the surface tension. You just see the underside of their foot. I'll have to get a picture of that for you. (The type of Ramshorn Snail I have is, I believe, Planorbis planorbis.)

Below: The gooey clear stuff is snail eggs. The lower glob of the two, which is neatly arranged in concentric circles (and looks kind of like a tiny ringworm here) is definitely laid by the Ramshorn Snails. The more prominent glob is probably from the snail pictured here.

That little guy is what they call, ever-so-specifically, a Pond Snail. After a little research, I think she's Physa sp. a.k.a. Physa Snail, Pouch Snail, or Tadpole Snail. This type and the Ramshorn Snails came to my pond as hitchhikers on plants, rather than deliberately introduced. I enjoy them nevertheless.

Finally, I can't believe I've never mentioned Isabella Rossellini's Green Porno, a series of fascinatingly bizarre short films, starring herself, about reproduction in the animal kingdom. At this time, I must recommend  Green Porno: Snail. You can see the entire series (plus Seduce Me) at the Sundance site.