Nature Study at the Sea: Sea Hare

This is a sea creature I saw at Leo Carrillo Beach yesterday. 

When we visited Abalone Cove, I mistakenly captioned a picture I took as being that of a sea slug. Well, yesterday, after watching the creature pictured below open and close its parapodial flaps, I noticed something lighter in color inside it. I put my finger between the flaps and felt something hard. Because I thought it was a sea slug, an animal that doesn't have a shell, I was surprised and confused. I had to know why it was opening its flaps and what the shell was.

I discovered that the animal I thought was a slug was actually a sea hare, named for the its hare-like "ears." The sea hare does have a shell inside, to protect its heart and gills. It has an input siphon and an output siphon for its gills, and I'm pretty sure now that the opening and closing of the parapodial flaps had to do with the sea hare breathing.

The sea hare is hermaphroditic, and it has a very bizarre way of mating. Here is a link to a National Geographic video explaining how the sea hare reproduces.