Portunus is a genus of crabs which includes several important species for fisheries, such as the blue swimming crab and the Gazami crab. Other species, such as the three-spotted crab are caught as bycatch.
Pinnotheres is a genus of crabs, including the pea crab. Many species formerly in Pinnotheres have been placed in new genera, such as Zaops ostreus, the oyster crab and Nepinnotheres novaezelandiae, the New Zealand pea crab. The species currently recognised in the genus Pinnotheres are:
Calappa is a genus of crabs known commonly as box crabs or shame-faced crabs. The name box crab comes from their distinctly bulky carapace, and the name shame-faced is from anthropomorphising the way the crab's chelae (claws) fold up and cover its face, as if it were hiding its face in shame.
Majidae is a family of crabs, comprising around 200 marine species inside 52 genera, with a carapace that is longer than it is broad, and which forms a point at the front. The legs can be very long in some species, leading to the name "spider crab". The exoskeleton is covered with bristles to which the crab attaches algae and other items to act as camouflage.
Macrophthalmus is a genus of crabs which are widespread across the Indo-Pacific. It contains the following species : Species in this genus are often referred to as sentinel crabs.
Parthenopidae is a family of crabs, placed in its own superfamily, Parthenopoidea. It comprises nearly 40 genera, divided into two subfamilies, with three genera incertae sedis:
Calappidae is a family of crabs containing 16 genera, of which 7 are only known as fossils:
Menippe is a genus of true crabs. One of the best known species is the Florida stone crab. Most of the species of this genus are found in the Atlantic Ocean.
Pilumnoidea is a superfamily of crabs, whose members were previously included in the Xanthoidea. The three families are unified by the free articulation of all the segments of the male crab's abdomen and by the form of the gonopods. The earliest fossils assigned to this group are of Eocene age.
Etisus is a genus of crabs, containing the following extant species:
Inachidae is a family of crabs, containing 39 genera:
Hemigrapsus is a genus of varunid crabs comprising thirteen species native almost exclusively in the Pacific Ocean, but two have been introduced to the North Atlantic region.
Leucosiidae is a family of crabs containing three subfamilies and a number of genera incertae sedis:
Actaea is a genus of crabs in the family Xanthidae, containing the following species:
Liomera is a genus of crabs in the family Xanthidae. It contains the following species:
Pilumnus is a genus of crabs, containing the following species:
Pisinae is a subfamily of crabs in the family Epialtidae, comprising the following genera:
Rochinia is a genus of crab in the family Epialtidae, containing the following species:
Calappilia is an extinct genus of box crabs belonging to the family Calappidae. The type species of the genus is Calappilia verrucosa.
