Pisidium nitidum, the shining pea clam, is a species of small freshwater clam, an aquatic bivalve mollusc in the family Sphaeriidae, the pea clams and fingernail clams.

shell is slightly tumid (swollen).

In shape it is regular-oval with low umbos slightly behind the midpoint.

The umbonal area is demarcated by three concentric furrows.

The surface (periostracum) is very glossy, with prominent irregularly spaced concentric striae.