They are oval-shaped and measure 2–8 mm (0.08–0.31 in) when mature.

Typically they are found near shorelines or the marginal growths near freshwater bodies, estuaries, and sea coasts.

[2] There are about 350 recognized species with the majority from the Nearctic and Palearctic.

[3] Many species are found in the intertidal zone and both adults and nymphs of some species like Saldula pallipes can tolerate submergence at high-tide.

They pass the winter through egg or adult diapause.