Xanthidae is a family of crabs known as gorilla crabs, mud crabs, pebble crabs or rubble crabs. Xanthid crabs are often brightly coloured and are highly poisonous, containing toxins which are not destroyed by cooking and for which no antidote is known. The toxins are similar to the tetrodotoxin and saxitoxin produced by puffer fish, and may be produced by bacteria in the genus Vibrio living in symbiosis with the crabs, mostly V. alginolyticus and V. parahaemolyticus.
Portunidae is a family of crabs which contains the swimming crabs. Its members include many well-known shoreline crabs, such as the blue crab and velvet crab. Two genera in the family are contrastingly named Scylla and Charybdis; the former contains the economically important species black crab and Scylla paramamosain.
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.
Lybia is a genus of small crabs in the family Xanthidae. Their common names include boxer crabs, boxing crabs and pom-pom crabs. They are notable for their mutualism with sea anemones, which they hold in their claws for defense. In return, the anemones get carried around, which may enable them to capture more food particles with their tentacles. Boxer crabs use at least three species of anemones, including Bundeopsis spp. and Triactis producta. The bonding with the anemone is not needed for survival, however, and boxer crabs have frequently been known to live without them, sometimes substituting other organisms such as sponges and corals for the sea anemones.
Ranina is a genus of crabs belonging to the family Raninidae. It has two extant species.
Paguristes is a genus of hermit crab in the family Diogenidae. It includes the following species :
Dairoidea is a superfamily of crabs, comprising two families which each contain a single genus: Dairidae and Dacryopilumnidae (Dacryopilumnus) .
Xantho is a genus of crabs in the family Xanthidae, containing five extant species, all restricted to the north-east Atlantic Ocean and Mediterranean Sea, although Xantho granulicarpis is not universally recognised as a separate species from Xantho hydrophilus:
Actaea is a genus of crabs in the family Xanthidae, containing the following species:
Paractaea 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:
Glyptoxanthus is a genus of crabs in the family Xanthidae, containing eight species. It was originally erected by Alphonse Milne-Edwards in 1879 for six species previously placed in the genus Actaea and elsewhere. Although previously included in subfamily Euxanthinae, the genus has a quite distinct morphology from other genera in that group, and was placed in 2011 in the new, monotypic subfamily, Glyptoxanthinae by Jose Christopher Mendoza and Danièle Guinot.
Cycloxanthops is a genus of crabs in the family Xanthidae, containing the following species:
Xanthias is a genus of crabs in the family Xanthidae, containing two exclusively fossil species and the following extant species:
Atergatis is a genus of crabs in the family Xanthidae, containing the following species:
Atergatopsis is a genus of crabs in the family Xanthidae, containing the following species:
Lophozozymus is a genus of crabs in the family Xanthidae, containing the following species:
Platypodia is a genus of crabs in the family Xanthidae, containing the following species:
Pseudophlyctenodes hantkeni is an extinct species of crab in the monotypic genus Pseudophlyctenodes, in the family Xanthidae. It is known from the Eocene of Hungary and Sicily.
Daira is a genus of crabs and is the only genus in the family Dairidae.
