ABSTRACT
The malacostracans are the largest class of crustaceans, having approximately 23000 species that are assigned to six superorders, four of which have species that live in subterranean environments. The Superorder Eucarida is one of these, and represents the most highly evolved group of malacostracans. Although three orders are assigned to the Eucarida, only the Decapoda are found in caves and other hypogean (below-surface) settings. Decapods are the largest and most diverse order of the Eucarida, with nearly 10000 marine, freshwater, and semiterrestrial species, and are characterized by the possession of a well-developed carapace enclosing a branchial (gill) chamber, three pairs of maxillipeds (mouthparts), and five pairs of functional pereiopods (=10 “legs”, thus the derivation of “Decapoda”). These crustaceans are significant components of hypogean, primarily aquatic communities in temperate and tropical regions of the world dominated mostly by volcanic or karst terrains.
