Pisidium pulchellum, the iridescent pea mussel, is a minute species of pea clam, a freshwater bivalve in the family Sphaeriidae.
The 3.5âÂÂ4 mm shell is tumid (swollen), oblique-oval shell. The umbos are broad well and well behind the midpoint. The surface (periostracum) is glossy with regular concentric ribbing. The colour is grey to cream tinged and pinkvor orange from the animal inside.