They are tan to brown in color and the elytra are abbreviated, leaving several tapering tergites of the abdomen exposed.

[2] Hydroscaphidae live on mats of algae with a thin layer of running water.

This may be the accumulated algae lining the very edge of a stream of water.

[3] They tolerate a wide range of temperatures; they have been observed in hot springs and in icy snowmelt.

In at least one species, the female lays a single large egg on the algal mat.