The majority of Paramysis species are brackish- or freshwater endemics of the Ponto-Caspian Basin; some of them naturally spread more than 500 kilometres (310 mi) up large rivers, including the Volga, Don, Dnieper and Danube.

Marine species from the Atlantic Ocean and Mediterranean Sea have probably descended from ancient Ponto-Caspian populations.

The largest species, like P. eurylepis, P. inflata, are found only in the Caspian Sea.

Generic characters: subrostral plate; large eyes on short stalk; antennal scale with smooth outer margin, ended by strong spine, and distal segment rudimentary with five setae; four segments of pereiopod 1–4 carpopropodus; five segments in pleopod 4 of male.

[3] Consumed by fishes; particularly important for juvenile sturgeons and zander.