{{Short description|Species of crab}} {{Speciesbox | image = Sponge crab eating a sea urchin.jpg | image_caption = ''T. dormia'' eating a sea urchin | genus = Tumidodromia | species = dormia | authority = (Linnaeus, 1763) | synonyms = *''Cancer lanosus'' <small>Rumphius, 1705</small> *''Cancer dormia'' <small>Linnaeus, 1763</small> *''Dromidiopsis dormia'' <small>(Linnaeus, 1763)</small> *''Cancer dormitator'' <small>Herbst, 1790</small> *''Dromia rumphii'' <small>Weber, 1795</small> *''Dromia hirsutissima'' <small>Dana, 1852</small> | synonyms_ref = &nbsp;<ref name="Davie">{{cite book |title=Zoological Catalogue of Australia: Crustacea: Malocostraca: Eucarida (Part 2), Decapoda: Anomura, Brachyura |isbn=978-0-643-05677-0 |author=P. J. F. Davie |publisher=CSIRO Publishing |year=2002 |pages=162 |chapter=''Dromia dormia'' (Linnaeus, 1763) |url=https://books.google.com/books?id=jr9SR1Cr5BAC&pg=PA162}}</ref><!--Ecology: coral reef, rock reef, subtidal; depth 8-50 m.--><ref name="McLay"/> }}

'''''Tumidodromia dormia''''', the '''sleepy sponge crab'''<ref>{{ITIS |id=660442 |taxon=''Dromia dormia''}}</ref> or '''common sponge crab''',<ref>{{cite web |url=http://www.sealifebase.org/summary/SpeciesSummary.php?id=21109&lang=English |title=''Dromia dormia'' (Linnaeus, 1763) |publisher=SeaLifeBase |accessdate=July 14, 2010}}</ref> is the largest species of sponge crab and the only species in the genus ''Tumidodromia''.<ref name="WoRMS">{{cite WoRMS|last=De Grave|first=Sammy|date=28 October 2019|title=''Tumidodromia'' McLay, 2009|id=439276|access-date=5 December 2024}}</ref> It grows to a carapace width of {{convert|20|cm|0|abbr=on}} and lives in shallow waters across the Indo-Pacific region.

==Distribution== ''Tumidodromia dormia'' has a widespread distribution in the Indo-Pacific region. Its range extends from East Africa (including Madagascar, the Seychelles and Mauritius) and the Red Sea through the Malay Archipelago, south to Queensland (Australia), north to China and Japan and as far east as Hawaii and French Polynesia.<ref name="Davie"/><ref name="McLay"/> It is mostly found in shallow waters, with the deepest record being {{convert|112|m|abbr=on}}.<ref name="McLay"/>

==Description== ''Tumidodromia dormia'' is the largest species in the family Dromiidae, at up to {{convert|200|mm}} across the carapace for males, and up to {{convert|172|mm|abbr=on}} for females.<ref name="McLay">{{cite journal |author=Colin L. McLay |year=2001 |title=The Dromiidae of French Polynesia and a new collection of crabs (Crustacea, Decapoda, Brachyura) from the Marquesas Islands |journal=Zoosystema |volume=23 |issue=1 |pages=77–100 |url=http://www.mnhn.fr/publication/zoosyst/z01n1a8.pdf |format=PDF |access-date=2010-07-15 |archive-url=https://web.archive.org/web/20110612062249/http://www.mnhn.fr/publication/zoosyst/z01n1a8.pdf |archive-date=2011-06-12 |url-status=dead }}</ref>

==Behaviour== Like other related crabs, ''T. dormia'' camouflages itself by carrying a sponge on its back, which it cuts to size with its claws, and then holds in place with its last two pairs of legs.<ref>{{cite book |title=The sea shore ecology of Hong Kong |author=Brian Morton & John Edward Morton |publisher=Hong Kong University Press |year=1983 |isbn=978-962-209-027-9 |chapter=Boulder shores |pages=86–128 |url=https://books.google.com/books?id=r79kKRbkzMwC&pg=PA187}}</ref> Instead of a sponge, ''T. dormia'' has occasionally been observed carrying other materials, including a hollow piece of wood, and the sole of a discarded shoe.<ref name="McLay"/>

==Life cycle== Little reproductive data is available for ''T. dormia''. One ovigerous (egg-carrying) female from the Marquesas Islands was carrying around 130,000 eggs, each 0.5&nbsp;mm in diameter.

==Taxonomic history== ''Tumidodromia dormia'' was among the first dromiid crabs to be collected, because of its large size and the fact that it occurs in shallow waters.<ref name="McLay"/> It was first described by Carl Linnaeus in his 1763 work ''Centuria Insectorum'', under the name ''Cancer Dormia''. An earlier description was published by Georg Eberhard Rumphius in his 1705 work ''De Amboinsche Rariteitkamer'', but this predates the starting point for zoological nomenclature.<ref name="Davie"/> There are a number of related species, which have often been confused with each other, including "''Dromia rumphii''", some examples of which are now considered to belong to ''Lauridromia dehaani''.<ref name="McLay"/>

==References==

{{Portal|Crustaceans}} {{Reflist}}

{{Taxonbar|from=Q3932665}}

Category:Dromiacea Category:Crustaceans described in 1763 Category:Animal taxa named by Carl Linnaeus