Leeches (Hirudinea)

A nice find, and classically striped.

Interesting ( and a bit gross ). Thanks @turb

The specimen appears to have annuli, and four dark dorsal stripes, the median pair of which are close and separated by a fine pale line. I am unable to determine details of the number of eyes and so on from the photo. A freshwater leech. Swimming leeches are generally flattened, as you noted.

This leech is actually the same species as Sighting 4422782