English: Crustaceans.
Zoology: crabs, lobsters, crayfish, shrimp, krill and barnacles; 67000 species; exoskeleton, they moult to grow; biramous, two-parted, limbs; nauplius form of the larvae; free-living aquatic animals, some are terrestrial (e.g. woodlice), some are parasitic (e.g. Rhizocephala, fish lice, tongue worms) and some are sessile (e.g. barnacles).
OrdersBranchiopodaPhyllopoda
Sarsostraca
RemipediaCephalocaridaMaxillopodaThecostraca
Tantulocarida
Branchiura
Pentastomida
Mystacocarida
Copepoda
OstracodaMyodocopa
Podocopa
MalacostracaPhyllocarida
Hoplocarida
Eumalacostraca