-Animals (Kingdom Animalia)

-Arthropods (Phylum Arthropoda)

-Crustaceans (Subphylum Crustacea)

-Typical Crustaceans (Superclass Multicrustacea)

-Malacostracans (Class Malacostraca)

-Decapods, Isopods, and Allies (Subclass Eumalacostraca)

-Decapods and Krill (Superorder Eucarida)

-Decapods (Order Decapoda)

-Crabs, Lobsters, Shrimps, and Allies (Suborder Pleocyemata)

-Anomurans (Infraorder Anomura)

-Squat Lobsters and Porcelain Crabs (Superfamily Galatheoidea)

-Porcelain Crabs (Family Porcellanidae)

-Genus Petrolisthes

-Petrolisthes lewisi

Petrolisthes lewisi is a member of the family of small marine crustaceans commonly known as porcelain crabs, noted for their flattened bodies, delicate appearance, and smooth, often shiny carapaces. Although they resemble true crabs, porcelain crabs are more closely related to squat lobsters and belong to the infraorder Anomura. They typically have large, broad claws (chelae) used for defense and display, while their fifth pair of legs is reduced and hidden beneath the carapace. Unlike many true crabs, most porcelain crabs are filter feeders, using feathery mouthparts (maxillipeds) to capture plankton from the water column, though some also scavenge. They inhabit rocky shores, coral reefs, and intertidal zones, often hiding under stones or living symbiotically with other marine invertebrates such as sea anemones. When threatened, they can quickly scuttle away or shed a claw to escape predators.