Sulphur Creek Snails

Day 172: Proof that I never outgrew being a tomboy, I came home from both of my last two trips to Sulphur Creek Falls with my shirt pocket full of snail shells. Fortunately at this time of the year, most of those I found were empty, so no snails were harmed in my efforts to identify two species common in western Washington forests. I learned a lot about gastropod biology while researching these, and if the thought of a pocketful of snails didn't ruin your breakfast, the best is yet to come. Those of you with weak stomachs should probably step away from the screen.

The critter on the right is Haplotrema vancouverense, aka the Robust Landtooth. Innocent as it may look, it is predatory on other gastropod species as well as being cannibalistic. It is very common in wet lowland forest, but often conceals itself under leaf litter, so mind where you step!

On the left is Monadenia fidelis, the Pacific Sideband. This species is hermaphroditic (as are many snails) and employs "love darts" during mating. The partners deploy sharp-pointed reproductive organs which not only serve to transfer sperm-boosting chemicals, but act as a deterrent to subsequent mating with another snail. According to National Geographic, "(I)t isn't clear whether the loss of libido is caused by a chemical on the darts or is a result of physical trauma."