Figure 1. The green porcelain crab Petrolisthes armatus can be found in rock rubble or oyster reefs in shallow intertidal or subtidal areas.

It occurs in the western Atlantic (Gulf of Mexico, Bermuda, the West Indies and Caribbean, and South America to southern Brazil), eastern Atlantic (tropical western Africa and Ascension Island), and eastern Pacific (Gulf of California to Peru). Since the 1990s it has invaded the Mid-Atlantic (South Carolina to Florida).