Trapeziidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

s, commonly known as coral crabs. All the species in the family are found in a close

symbiosis Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can fo ...

with

cnidaria Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

ns. They are found across the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, and can best be identified to the species level by the colour patterns they display. Members of the family Tetraliidae were previously included in the Trapeziidae, but the similarities between the taxa is the result of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

Subfamilies and genera

The

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

lists the following subfamilies and genera: '' Calocarcininae'' Stevcic, 2005 *'' Calocarcinus'' Calman, 1909 *'' Philippicarcinus'' Garth & Kim, 1983 *'' Sphenomerides'' Rathbun, 1897 '' Quadrellinae'' Stevcic, 2005 *'' Hexagonalia'' Galil, 1986 *'' Hexagonaloides'' Komai, Higashiji & Castro, 2010 *'' Quadrella'' Dana, 1851 '' Trapeziinae'' Miers, 1886 *'' Trapezia'' Latreille, 1828

References

Crabs Taxa named by Edward J. Miers Decapod families {{Eubrachyura-stub