Cryptochiridae Explained

Cryptochiridae is a family of crabs known commonly as gall crabs or coral gall crabs. They live inside dwellings in corals and cause the formation of galls in the coral structure.^{[1] [2]} The family is currently placed in its own superfamily, Cryptochiroidea.

Gall crabs are sexually dimorphic, with males being much smaller than females. Contrary to females, most males are free-living and "visit" females for mating.^{[1] [3]}

These crabs are most common in shallow waters where they live in association with stony corals, but they have also been recorded from mesophotic zones and deep waters.^{[4] [5]} They likely feed on mucus secreted by their coral hosts, as well as various detritus. Some species are thought to be filter feeders.^[1]

Because crab size is related to gall size, it is likely that the crabs form the galls, rather than living randomly in a dwelling within a coral. Related groups of gall crab taxa share a similar gall type, suggesting that the crabs influence the morphology of the galls.^[6]

The family contains the following twenty-one genera:^{[7] [8]}

• Cecidocarcinus Kropp & Manning, 1987
• Cryptochirus Heller, 1861
• Dacryomaia Kropp, 1990
• Detocarcinus Kropp & Manning, 1987
• Fizesereneia Takeda & Tamura, 1980
• Fungicola Serene, 1966
• Hapalocarcinus Stimpson, 1859
• Hiroia Takeda & Tamura, 1981
• Kroppcarcinus Badaro, Neves, Castro & Johnsson, 2012
• Lithoscaptus A. Milne-Edwards, 1862
• Luciades Kropp & Manning, 1996
• Neotroglocarcinus Fize & Serene, 1957
• Opecarcinus Kropp & Manning, 1987
• Pelycomaia Kropp, 1990
• Pseudocryptochirus Hiro, 1938
• Pseudohapalocarcinus Fize & Serène, 1956
• Troglocarcinus Verrill, 1908
• Sphenomaia Kropp, 1990
• Utinomiella Kropp & Takeda, 1988
• Xynomaia Kropp, 1990
• Zibrovia Kropp & Manning, 1996

Notes and References

1. Johnsson, R., et al. (2006). The association of two gall crabs (Brachyura: Cryptochiridae) with the reef-building coral Siderastrea stellata Verrill, 1868. Hydrobiologia 559(1), 379-84.
2. Kropp, R. K. (1990). Revision of the genera of gall crabs (Crustacea: Cryptochiridae) occurring in the Pacific Ocean. Pacific Science 44(4) 417-48.
3. van der Meij, S.E.T. (2014). Host species, range extensions, and an observation of the mating system of Atlantic shallow-water gall crabs (Decapoda: Cryptochiridae) Bulletin of Marine Science 90,1001-1010.
4. van der Meij, S.E.T., et al. (2015). A mesophotic record of the gall crab Opecarcinus hypostegus from a Curaçaoan reef. Bulletin of Marine Science 91, 205-206.
5. van Tienderen, K.M. & S.E.T. van der Meij (2016). Occurrence patterns of coral-dwelling gall crabs (Cryptochiridae) over depth intervals in the Caribbean. PeerJ 4, e1794.
6. Wei, T. P., et al. (2013). Gall polymorphism of coral-inhabiting crabs (Decapoda, Cryptochiridae): a new perspective. Journal of Marine Science and Technology 21, 304-07.
7. [WoRMS]
8. . 2008 . 17 . 1–286 . Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran crabs of the world . P. K. L. Ng, D. Guinot & P. J. F. Davie . dead . https://web.archive.org/web/20110606061453/http://rmbr.nus.edu.sg/rbz/biblio/s17/s17rbz.pdf . 2011-06-06 .