Crustaceans includes crabs, crayfish, lobsters, shrimp, isopods, and barnacles (at least 67,000 described species). Most crustaceans are aquatic animals, but others adapted to live on land (e.g., land-crabs, woodlice). On this website, all crustaceans (including freshwater and terrestrial species) are encompassed in marine invertebrates, for simplicity.

 

Decapoda

Stenopodidae (Stenopoid Shrimps)

Palaemonidae (Palaemonid Shrimps)

Palinuridae (Lobsters)

Coenobitidae (Hermit Crabs)

Diogenidae (Left-handed Hermit Crabs)

Cancridae (Rock Crabs)

Gecarcinidae (Land Crabs)

Grapsidae (Shore Crabs)

Majidae (Spider Crabs)

Ocypodidae (Ghost Crabs and Fiddler Crabs)

Portunidae (Swimming Crabs)

Pseudothelphusidae (Manicou Crabs)

Isopoda

Asellidae (Freshwater Isopods)