Ok. This is an image upload experiment. I had to click the "start" button to start the actual upload. Then I was given two BB-code links, one to a thumbnail and one to the full size image (which I sized down to 700 pixels wide before the upload). I had to cut and paste the BB-code link from the upload form into the body of the post. Will it work? Or will it won't?
This is an aquatic worm. They are little different than earth worms other than size and habitat. They do tend to be smaller than earth worms. They do live under water. They are common trout stream critters, at least down low where the rivers are a bit siltier. I'm not sure but I don't think there are any aquatic worms in cold high altitude gravel bottom torrents. These are farmland creatures. Although, farmland trout habitat is where the biggest fish live.
Everybody ties red San Juan Worms which is interesting because there is no such thing as a red worm, and yet the red flies work. But so do browner, more realistic worm flies.
Anyway. These are real. They are aquatic. I didn't know they even existed until I netted one, scratched my head and looked it up. Fish do eat them.