Sand bubbler crab

{{Short description|Genus of crabs}} {{Taxobox | image = Kometsukigani_06g0139v.jpg | image_caption = ''Scopimera globosa'' | regnum = Animalia | phylum = Arthropoda | subphylum = Crustacea | classis = Malacostraca | ordo = Decapoda | infraordo = Brachyura | familia = Dotillidae | genus = '''''Scopimera''''' De Haan, 1833 '''''Dotilla''''' Stimpson, 1858 | subdivision_ranks = Species | subdivision = See text }}

'''Sand bubbler crabs''' (or sand-bubblers) are crabs of the genera '''''Scopimera''''' and '''''Dotilla'''''<ref name="Maitland">{{cite journal |journal=Nature |volume=319 |pages=493–495 |year=1986 |doi=10.1038/319493a0 |title=Crabs that breathe air with their legs - ''Scopimera'' and ''Dotilla'' |author=David P. Maitland |issue=6053|bibcode=1986Natur.319..493M |s2cid=4362098 }}</ref> in the family Dotillidae.<ref name="Ng">{{cite journal |journal=Raffles Bulletin of Zoology |year=2008 |volume=17 |pages=1–286 |title=Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran crabs of the world |author=Peter K. L. Ng |author2=Danièle Guinot |name-list-style=amp |author3=Peter J. F. Davie |url=https://rmbr.nus.edu.sg/rbz/biblio/s17/s17rbz.pdf}}</ref> They are small crabs that live on sandy beaches in the tropical Indo-Pacific. They feed by filtering sand through their mouthparts, leaving behind balls of sand<ref name=hunt>{{Cite book |url=https://books.google.com/books?id=o-W7CgAAQBAJ&pg=PA138 |title=The Hunt |last1=Fothergill |first1=Alastair |last2=Cordey |first2=Huw |publisher=Ebury Publishing |year=2015 |isbn=9781448141890 |pages=138 |language=en}}</ref> that are broken up by the incoming high tide.

==Description== Sand bubbler crabs are small crabs, around {{convert|1|cm|1|abbr=on}} across the carapace, and they are characterised by the presence of "gas windows" on the merus of the legs; in ''Dotilla'', these windows are also present on the thoracic sternites.<ref name="Maitland"/> A similar system has evolved in parallel in the porcelain crab genus ''Petrolisthes''.<ref>{{cite book |title=Crustaceans and the Biodiversity Crisis: Proceedings of the Fourth International Crustacean Congress, Amsterdam, the Netherlands, July 20–24, 1998 |series=Crustacean Issues |volume=12 |editor1=Frederick R. Schram |name-list-style=amp |editor2=J. C. von Vaupel Klein |publisher=Brill |year=1999 |isbn=978-90-04-11387-9 |chapter=Physiological diversity and the colonization of land |author=Peter Greenaway |pages=823–842}}</ref>

==Distribution== Sand bubbler crabs are widespread across the Indo-Pacific region, where they occur abundantly on sandy beaches in the tropics and sub-tropics.<ref name="Maitland"/>

==Ecology and behaviour== [[File:Scopimera in Tanjung Aru Beach 2b.jpg|thumb|left|''Scopimera globosa'' and the sand pellets it has made]] Sand bubbler crabs live in burrows in the sand, where they remain during high tide. When the tide is out, they emerge on to the surface of the sand, and pass the sand through their mouthparts, eating detritus and plankton,<ref name=BreathLegs>{{Cite magazine |url=https://books.google.com/books?id=DdVo4x0OaUAC&pg=PA24 |title=Legs that are made for breathing |date=February 20, 1986 |magazine=New Scientist |page=24}}</ref> and discarding the processed sand as pellets, which cover the beach. The crabs work radially from the entrance to their burrows, which they re-enter as the tide rises and disintegrates the pellets.<ref>{{cite book |title=Carbonate Sediments and their Diagenesis |volume=12 |series=Developments in Sedimentology |author=Robin G. C. Bathurst |author-link=Robin Gilbert Charles Bathurst |edition=2nd |publisher=Elsevier |year=1975 |isbn=978-0-444-41353-6 |chapter=The Trucial coast embayment, Persian Gulf |pages=178–211}}</ref> In each burrow, the crab waits out the high tide in a bubble of air.<ref name=BreathLegs /> The material consumed by sand bubbler crabs has a very low concentration of organic matter, which is concentrated by egestion of indigestible material.<ref>{{cite book |title=Ecology: Principles and Applications |author=J. L. Chapman |name-list-style=amp |author2=M. J. Reiss |edition=2nd |publisher=Cambridge University Press |year=1999 |isbn=978-0-521-58802-7 |chapter=The individual |pages=5–15}}</ref>

==Taxonomy== ===Taxonomic history=== The first sand bubbler crab to be described was ''Cancer sulcatus'' (now ''Dotilla sulcata'') by Peter Forsskål in 1775. The genus ''Scopimera'' was originally described as a subgenus of ''Ocypode'' by Wilhem de Haan in 1833, although the first species, ''Scopimera globosa'' was not validly described until 1835.<ref name="Ng"/> At the same time, De Haan tried to erect the genus ''Doto'' for Forskål's ''Cancer sulcatus'', not realising that the name was preoccupied by the mollusc genus ''Doto''. The first available name for that genus was published by William Stimpson in 1858, who called it ''Dotilla''. Ongoing revisions are likely to split the current genus ''Scopimera'' into at least two genera.<ref name="Ng"/>

===Species=== Eight species of ''Dotilla'' and fifteen of ''Scopimera'' are currently recognised:<ref name="Ng"/> {{div col|colwidth=24em}} * '''''Dotilla''''' ** ''Dotilla blanfordi'' Alcock, 1900 ** ''Dotilla fenestrata'' Hilgendorf, 1869 ** ''Dotilla intermedia'' De Man, 1888 ** ''Dotilla malabarica'' Nobili, 1903 ** ''Dotilla myctiroides'' (H. Milne-Edwards, 1852) ** ''Dotilla pertinax'' Kemp, 1915 ** ''Dotilla sulcata'' (Forskål, 1775) ** ''Dotilla wichmanni'' De Man, 1892 {{div col end}} {{div col|colwidth=24em}} * '''''Scopimera''''' ** ''Scopimera bitympana'' Shen, 1930 ** ''Scopimera crabicauda'' Alcock, 1900 ** ''Scopimera curtelsoma'' Shen, 1936 ** ''Scopimera globosa'' (De Haan, 1835) ** ''Scopimera gordonae'' Serène & Moosa, 1981 ** ''Scopimera inflata'' A. Milne-Edwards, 1873 ** ''Scopimera intermedia'' Balss, 1934 ** ''Scopimera investigatoris'' Alcock, 1900 ** ''Scopimera kochi'' Roux, 1917 ** ''Scopimera longidactyla'' Shen, 1932 ** ''Scopimera philippinensis'' Wong, Shih & Chan, 2011<ref name="ZT2962">{{cite journal |author=Kingsley J. H. Wong, Hsi-Te Shih & Benny K. K. Chan |year=2011 |title=Two new species of sand-bubbler crabs, ''Scopimera'', from North China and the Philippines (Crustacea: Decapoda: Dotillidae) |journal=Zootaxa |volume=2962 |pages=21–35 |doi=10.11646/zootaxa.2962.1.2 |url=https://www.mapress.com/zootaxa/2011/f/zt02962p035.pdf }}</ref> ** ''Scopimera pilula'' Kemp, 1919 ** ''Scopimera proxima'' Kemp, 1919 ** ''Scopimera sheni'' Wong, Shih & Chan, 2011<ref name="ZT2962"/> ** ''Scopimera sigillorum'' (Rathbun, 1914) {{div col end}}

==References== {{Reflist|40em}}

==External links== * {{Commons category-inline|Scopimera|''Scopimera''}}

Category:Ocypodoidea Category:Arthropod common names