View source for Golden ghost crab

{{short description|Species of crustacean}}
{{Redirect|Ocypode convexus|the crab species originally described as Ocypode (Chasmagnathus) convexus|Chasmagnathus}}
{{EngvarB|date=November 2013}}
{{Use dmy dates|date=November 2013}}
{{Speciesbox
| name = Golden ghost crab
| image =101116 Ghost crab Gnaraloo Bay Rookery.JPG
| image_caption = A golden ghost crab from [[Gnaraloo]], Western Australia
| image2 = 110209 GTCP Field Diary Red crab Photo 2.JPG
| image2_caption = A golden ghost crab covered with [[epibiotic]] growth, making it appear pink
| taxon = Ocypode convexa
| authority = [[Jean René Constant Quoy|Quoy]] & [[Joseph Paul Gaimard|Gaimard]], 1824
| synonyms = 
*''Ocypode bombée''<br><small>[[Henri Milne-Edwards|H. Milne-Edwards]], 1837</small>
*''Ocypode pygoides''<br><small>[[Arnold Edward Ortmann|Ortmann]], 1894a</small>
| synonyms_ref=<ref name="sakai"/> 
| range_map =Ocypode convexa distribution map.jpg
| range_map_caption =''Ocypode convexa'' distribution range<br>(in green)
}}
'''''Ocypode convexa''''', commonly known as the '''golden ghost crab''', or alternatively the '''western ghost crab''' or '''yellow ghost crab''', is a [[species]] of [[Ocypodinae|ghost crab]]s [[endemism|endemic]] to the coast of Western Australia, from [[Broome, Western Australia|Broome]] to [[Perth]]. They are relatively large ghost crabs, with a [[carapace]] growing up to {{convert|45|mm|in|abbr=on}} long and {{convert|52|mm|in|abbr=on}} wide. They are easily recognisable by their golden yellow colouration. Like other ghost crabs they have box-like bodies with unequally sized claws. They also have large [[eyestalk]]s with the [[cornea]] occupying most of the bottom part.

Golden ghost crabs are common inhabitants of open sandy beaches, living in burrows in the [[intertidal zone|intertidal]] and [[supratidal zone]]s. They are predominantly nocturnal and semi-terrestrial. They are a [[generalist species]], feeding on [[carrion]] and [[debris]], as well as [[predation|prey]]ing on small animals. Along with the red fox (''[[Vulpes vulpes]]''), they are significant as one of the main predators of eggs and hatchlings of Western Australian [[sea turtle]]s, particularly the [[Endangered]] loggerhead sea turtle (''[[Caretta caretta]]'') which has one of the largest [[rookeries]] in the region.

==Classification==
''Ocypode convexa'' is classified under the [[genus]] ''[[Ocypode]]'' in the ghost crab [[subfamily (biology)|subfamily]] [[Ocypodinae]] of the [[family (biology)|family]] [[Ocypodidae]].<ref name="worms">{{cite WoRMS|author=Peter J. F. Davie|year=2013|id=444984 |title=''Ocypode convexa'' Quoy & Gaimard, 1824 |db=Crustacea|accessdate=15 November 2013}}</ref> It was first described by the French [[naturalist]]s [[Jean René Constant Quoy]] and [[Joseph Paul Gaimard]] in 1824 as ''Ocypode convexus''.<ref group="note">The specific name has been emended to ''Ocypode convexa'' because the [[grammatical gender]] of the genus ''Ocypode'' is feminine. The [[International Code of Zoological Nomenclature]] requires [[International Code of Zoological Nomenclature#Gender agreement|gender agreement]] between the specific name and the generic name.</ref> The [[type specimen]]s were recovered from [[Dirk Hartog Island]], [[Shark Bay]], Western Australia, during the [[circumnavigation]]al voyage of the French [[corvette]]s ''Uranie'' and ''Physicienne'' (1817–1820) under the command of [[Louis de Freycinet]].<ref name="quoy">{{cite book|author1=Jean René Constant Quoy |author2=Joseph Paul Gaimard |editor =Louis de Freycinet|title =Voyage autour du monde fait par ordre du Roi sur les corvettes de S. M. l'Uranie et la Physicienne, pendant les années 1817, 1818, 1819 et 1820|chapter =Zoologie|publisher =Chez Pillet Aîné|year =1824|page=525, pl. 77|url =https://www.biodiversitylibrary.org/bibliography/15862#/summary}}</ref><ref name="davie">{{cite book|author=Peter J. F. Davie|editor =Peter J. F. Davie|title =Crustacea: Malacostraca: Phyllocarida, Hoplocaroda, Eucarida (Part 1)|chapter =Introduction|publisher =CSIRO Publishing|series =Zoological Catalogue of Australia, Volume 19.3A|year =2002|page=2|isbn =9780643056770|chapter-url =https://books.google.com/books?id=Sc7i6AL-GewC&q=Ocypode+convexa&pg=PA2}}</ref>

===Etymology===
While the [[species|specific name]] is derived from [[Latin]] ''[[wikt:convexus|convexus]]'' ("vaulted" or "domed"). The latter is a direct translation of Quoy and Gaimard's "French name" of the species, ''Ocypode bombé'', referring to the dome-like shape of the [[carapace]].<ref name="quoy"/>

They are commonly known as the "golden ghost crab".<ref name="wam">{{cite web|url=http://museum.wa.gov.au/explore/blogs/museummarine/creature-feature-haunted-beaches-fleet-footed-ghost-crabs|title=Creature Feature – Haunted Beaches: The fleet-footed Ghost Crabs|author=Western Australian Museum|year=2011|publisher=Government of Western Australia|access-date=12 November 2013}}</ref><ref name="natur">{{cite web|url=http://www.nmdc.com.au/fishy-fun-learning/marine-life-in-focus/golden-ghost-crab/|title=Golden Ghost Crab|author=Naturaliste Marine Discovery Centre|publisher=Government of Western Australia|access-date=12 November 2013|url-status=dead|archive-url=https://archive.today/20131112105805/http://www.nmdc.com.au/fishy-fun-learning/marine-life-in-focus/golden-ghost-crab/|archive-date=12 November 2013|df=dmy-all}}</ref> They are also sometimes referred to as the "western ghost crab",<ref name="poore">{{cite book|author1=Gary C. B. Poore |author2=Shane T. Ahyong |title =Marine Decapod Crustacea of Southern Australia: A Guide to Identification|url=https://archive.org/details/marinedecapodcru00poor |url-access=limited |publisher =CSIRO Publishing|year =2004|page=[https://archive.org/details/marinedecapodcru00poor/page/n538 496]|isbn =9780643069060}}</ref><ref name="kdav"/> or the "yellow ghost crab".<ref name="leeden"/>

===Taxonomic history===
The species was more widely known in scientific literature by its [[junior synonym]] ''Ocypode pygoides'' in the early 20th century due to the uncertainty regarding the original descriptions and illustrations by Quoy and Gaimard.<ref name="sakai"/> 
[[File:Ocypode convexa - 1824 illustration.jpg|left|thumb|[[Jean René Constant Quoy]] and [[Joseph Paul Gaimard]]'s original 1824 illustration of ''Ocypode convexa''<ref name="quoy"/>]]
In 1837, the French [[zoologist]] [[Henri Milne-Edwards]] used Quoy and Gaimard's French "translation" of the name, ''Ocypode bombé'' (writing it as ''Ocypode bombée''), instead of the Latin name, ''Ocypode convexus''. However, he also declared that the species "hadn't been described or illustrated in enough detail for it to be recognised in some way".<ref name="milne-ed">{{cite book|author=Henri Milne-Edwards|title =Histoire naturelle des crustacés, comprenant l'anatomie, la physiologie et la classification de ces animaux. Volume 2|publisher =Librairie Encyclopédique de Roret|year =1837|page=49|url =https://www.biodiversitylibrary.org/bibliography/6234#/summary}}</ref><ref group="note">French:''"... n'a pas été décrite ni figurée avec assez de détail pour pouvoir être reconnue d'une manière certaine."''</ref> The British zoologist [[Edward J. Miers]] also regarded it as a possible synonym of either ''[[Ocypode kuhlii]]'' or ''[[Ocypode cordimanus]]'' in 1882, again due to the vagueness of the original descriptions.<ref name="sakai"/><ref name="miers">{{cite journal|author=Edward J. Miers|year=1882|title=On the species of ''Ocypoda'' in the collections of the British Museum|journal=Annals and Magazine of Natural History|volume=5|issue=5|pages=304–317|url=https://archive.org/details/annalsmagazineof5101882lond}}</ref> In 1894, the Prussian-American zoologist [[Arnold Edward Ortmann]] described ''Ocypode pygoides'' without consulting Quoy and Gaimard's original work. Although he did posit the possibility that ''Ocypode pygoides'' and ''Ocypode convexa'' might actually be the same species later on in 1897.<ref name="sakai"/><ref name="ort">{{cite journal|author=Arnold Edward Ortmann|year=1897|title=Carcinologische Studien|journal=Zoologische Jahrbücher, Abteilung für Systematik, Ökologie und Geographie der Tiere|volume=10|pages=358–372|url=http://decapoda.nhm.org/pdfs/28108/28108-002.pdf}}</ref><ref group="note">German: ''"Nach der Localität und dem Habitusbild wäre es möglich, dass diese Art dieselbe ist wie pygoides. Beschreibung und Abbildung geben aber keine Einzelheiten, die dies gewiss machen könnten."'' (English: "After the locality and habitus image, it is possible that this species is the same as ''pygoides''. But the descriptions and illustrations do not provide any details that could make this certain.")</ref>

In 1957, due to the discovery of a name conflict with an unrelated crab species also originally described as ''Ocypode convexus''<ref group="note">As ''Ocypode'' (''Chasmagnathus'') ''convexus'', now [[valid name (zoology)|valid]] as ''[[Chasmagnathus convexus]]''</ref> by the Dutch zoologist [[Wilhem de Haan]] in 1833, the [[International Commission on Zoological Nomenclature]] (ICZN) [[suppressed name|suppressed]] Quoy and Gaimard's ''Ocypode convexus''. This ruling was made on the basis that the consulted specialists regarded Quoy and Gaimard's ''Ocypode convexus'' as ''[[nomen dubium]]''.<ref name="hemming">{{cite book|editor =Francis Hemming|title =Opinions and Declarations Rendered by the International Commission on Zoological Nomenclature. Volume 1. Section E|chapter =Direction 86: Validation under the Plenary Powers of the specific name ''convexa'' de Haan, [1883], as published in the combination ''Ocypode'' (''Chasmagnathus'') ''convexa'' (Class Crustacea, Order Decapoda) (''Direction'' supplementary to ''Opinion 85'')|publisher =International Commission on Zoological Nomenclature|year =1957|page=[https://archive.org/details/opinionsdeclar1195758inte/page/403 403]|url =https://archive.org/details/opinionsdeclar1195758inte}}</ref>

It wasn't until 1965 when the Australian carcinologists [[Ray W. George]] and [[Mary E. Knott]] finally clarified the confusion surrounding the name by demonstrating that ''Ocypode pygoides'' and ''Ocypode convexa'' were identical and formally synonymised the former with the latter. The name ''Ocypode convexa'' is now regarded as the [[valid name (zoology)|valid name]] and the species has been referred to as such in subsequent publications.<ref name="sakai"/>

''[[Ocypode stimsponii]]'', a different species found in East Asia, was also initially described by the American zoologist [[William Stimpson]] as ''Ocypode convexa'' in 1858. Like de Haan, Stimpson was unaware that the name had already been used previously by Quoy and Gaimard. Ortmann realised that Stimpson's name for the species was a [[Homonym (biology)|junior homonym]] in 1897 and renamed the species ''Ocypode stimpsonii''. ''[[Ocypode nobilii]]'', another species from Southeast Asia, was also mistakenly identified as ''Ocypode convexa'' on its discovery in 1899 by the Italian carcinologist [[Giuseppe Nobili]]. In 1902, the Dutch biologist [[Johannes Govertus de Man]] recognised that it was actually a new species and named it ''Ocypode nobilii'' in honour of Nobili.<ref name="sakai">{{cite journal|author1=Katsushi Sakai |author2=Michael Türkay |year=2013|title=Revision of the genus ''Ocypode'' with the description of a new genus, ''Hoplocypode'' (Crustacea: Decapoda: Brachyura)|journal=Memoirs of the Queensland Museum – Nature|volume=56|issue=2|pages=665–793|url=http://www.qm.qld.gov.au/~/media/Documents/QM/About%20Us/Publications/Memoirs%20-%20Nature/N56-2/qmn56-2-sakaiturkay.pdf}}</ref>

==Description==
Golden ghost crabs are relatively large and robust ghost crabs with strong legs and claws. Their [[carapace]] is deep and box-like in shape, and can grow to a length of up to {{convert|45|mm|in|abbr=on}} and a width of {{convert|52|mm|in|abbr=on}}.<ref name="kdav"/><ref name="balss">{{cite journal|author=Heinrich Balss|year=1935|title=Brachyura of the Hamburg Museum Expedition to South-Western Australia, 1905|journal=Journal of the Royal Society of Western Australia|volume=21|pages=113–151|url=http://decapoda.nhm.org/pdfs/13304/13304.pdf}}</ref> They are easily identifiable by their colouration. As their common name implies, the overall colour of golden ghost crabs is usually creamy white to a rich golden yellow with faint brown markings.<ref name="kdav">{{cite web|url=http://www.environment.gov.au/cgi-bin/species-bank/sbank-treatment.pl?id=78342|title=''Ocypode convexa'' (Family Ocypodidae)|author=Keith Davey|date=7 February 2007|publisher=[[Department of the Environment, Water, Heritage and the Arts]]|work=SpeciesBank |access-date=15 November 2013}}</ref>
[[File:Ocypode convexa carapace profile and stridulating ridge.png|thumb|left|''Ocypode convexa'' eyestalks and anterior profile of the [[carapace]] ('''top'''); and the [[stridulation|stridulating]] ridge (a row of 19 to 24 tubercles) on the larger [[Chela (organ)|claw]] ('''bottom''').<ref name="sakai"/><ref name="miers"/>]]
Like other ghost crabs, the eyestalks of golden ghost crabs are large and swollen, with the cornea occupying the lower surface. Their tips do not extend into a spike (style) making them easy to distinguish from the similarly-sized horned ghost crab (''[[Ocypode ceratophthalma]]'') which also occurs in Western Australia. The upper margins of the eye orbits curve around the bases of the eyestalks, then gently curve again towards the sides of the carapace. The outer edges of the upper margins of the eye orbits are triangular in shape and distinctly pointing forward.<ref name="sakai"/> The lower margins of the eye orbits have deep notches on the center and on the sides.<ref name="poore"/>

The carapace is wider than it is long, being broadest at the width between the outer edges of the eye orbits. The upper surface is covered densely with small bumps (tubercles) that gradually become sparser towards the anterolateral regions. The carapace bulges outward on the outer thirds and is separated from the central regions by shallow furrows.<ref name="sakai"/>

As in other members of the family Ocypodidae, one of the claw appendages ([[cheliped]]s) of golden ghost crabs is much larger than the other. This occurs in both males and females, though the difference is much more pronounced in males.<ref name="sakai"/><ref name="kdav"/>

The palm ([[Arthropod leg#Crustacea|propodus]])<ref group="note">The second to the last segment of [[Arthropod leg#Crustacea|crustacean appendages]]</ref> of both larger and smaller chelipeds are covered coarsely with large irregularly-arranged tubercles on the outer surface, giving them a rough appearance. The larger [[Chela (organ)|claw]] is longer than it is wide, with its upper and lower edges possessing rows of spine-like tubercles, arranged irregularly on the upper margin and regularly on the lower margin. The inner surface of the palm of the larger claw in both sexes features [[Stridulation|stridulating]] (sound-producing) ridges, which is important for identifying different species within the subfamily Ocypodinae. In golden ghost crabs, the stridulating ridge is composed of a row of 19 to 24 tubercles. The smaller cheliped tapers towards a pointed end.<ref name="sakai"/>
[[File:121129 GGC eating Octopus Gnaraloo Bay Rookery.JPG|thumb|Golden ghost crabs eating a dead octopus]]
The propodi of the first and second pair of walking legs possess bristles ([[setae]]) on the upper surfaces and the upper margins, while the propodi of the third and fourth pair of walking legs are naked. The first [[gonopod]] (appendages modified into sexual organs) of the male is three-sided in cross-section at the base, narrowing towards a sideways-curving tip. A bulging palp is present at the sides near the tip. The rim of the genital opening in females is horn-shaped and located in front of the genital covering (operculum). The operculum is rounded in shape.<ref name="sakai"/>

==Ecology and behaviour==
<!--{{multiple image
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| image1 =100212 Golden ghost crab prey Loggerhead hatchling Gnaraloo Bay Rookery 01.JPG
| alt1 =
| caption1 =Golden ghost crab preying on a loggerhead sea turtle (''[[Caretta caretta]]'') hatchling
| image2 =111206 Ghost crab predation Gnaraloo Bay Rookery.JPG
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| caption2 =Golden ghost crabs can burrow into sea turtle nests to feed on the eggs
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Like other ghost crabs, golden ghost crabs are predominantly nocturnal, though they may sometimes emerge during the day.<ref name="wam"/><ref name="kdav"/> They are semi-terrestrial and breathe oxygen from the air through moistened [[gills]].<ref name="natur"/> They must periodically wet their gills with seawater, usually by taking water from moist sand or by running into the surf and letting the waves wash over them.<ref name="wam"/> However, in 1962, the Australian zoologist [[William Ride]] reported golden ghost crabs foraging inland as far as {{convert|500|m|ft|abbr=on}} away from the sea following heavy rains. This indicates that they are able to tolerate freshwater, and can still breathe by taking in moisture through wet vegetation.<ref name="kdav"/> Golden ghost crabs must return to the sea to release their eggs. They hatch into marine [[plankton]]ic larvae.<ref name="wam"/>

Golden ghost crabs live in deep burrows in the [[intertidal zone|intertidal]] and [[supratidal zone]]s of open sandy beaches.<ref name="kdav"/> Some burrows may be found as much as {{convert|12|to|20|m|ft|abbr=on}} away from the [[high water mark]] and in the [[dune]] zone, but they are densest in the intertidal zone (71%).<ref name="kdav"/><ref name="gtcp11"/> The burrows are vertically constructed, with the bottom commonly situated south of the entrance. It is believed that this is to prevent sunlight from shining into the burrow during the day.<ref name="poore"/><ref name="kdav"/> 
[[File:100212 Golden ghost crab prey Loggerhead hatchling Gnaraloo Bay Rookery 01.JPG|thumb|A golden ghost crab preying on a loggerhead sea turtle (''[[Caretta caretta]]'') hatchling at [[Gnaraloo]], Western Australia]]
They are swift runners, darting away to their burrows at the slightest sign of danger.<ref name="wam"/> In the presence of potential threats (like humans), golden ghost crabs have been observed to only raise one eyestalk at a time, keeping the other one protected within its eye orbit. This may be to avoid having both eyes damaged in case of an attack.<ref name="kdav"/>

Golden ghost crabs are a [[generalist species]].<ref name="natur"/> They [[scavenger|scavenge]] [[carrion]] and [[debris]] like dead fish or [[seaweed]] washed up by the waves; as well as [[predator|prey]] on small animals like [[mollusc]]s, other [[crustacean]]s, and [[sea turtle]] [[hatchling]]s.<ref name="wam"/><ref name="kdav"/>

===Effects on sea turtle conservation===
The Western Australian coast is the site of a significant number of rookeries of loggerhead sea turtles (''[[Caretta caretta]]''), green sea turtles (''[[Chelonia mydas]]''), and hawksbill sea turtles (''[[Eretmochelys imbricata]]''), all of which are classified [[Endangered]] to [[Critically Endangered]]. The nesting sites are particularly numerous for loggerhead sea turtles, whose rookeries from [[Shark Bay]] to [[Gnaraloo Bay]], [[Ningaloo Reef]], and the [[Cape Range National Park]] are some of the largest in the world.<ref name="gtcp09">{{cite book|author1=Karen Hattingh |author2=Patrick Becker |author3=Grant Peterson |title =Gnaraloo Turtle Conservation Program – Final Report 08/09 : Beach Monitoring: Nesting Season 2008/2009|publisher =Gnaraloo Marine Turtle Research Program, Gnaraloo Station Trust|year= 2009|url =http://ningaloo-atlas.org.au/sites/default/files/Gnaraloo%20turtle%20conservation%20program%202008_09%20final%20report.pdf}}</ref><ref name="troc"/><ref name="conant">{{cite book |author1=Therese A. Conant |author2=Peter H. Dutton |author3=Tomoharu Eguchi |author4=Sheryan P. Epperly |author5=Christina C. Fahy |author6=Matthew H. Godfrey |author7=Sandra L. MacPherson |author8=Earl E. Possardt |author9=Barbara A. Schroeder |author10=Jeffrey A. Seminoff |author11=Melissa L. Snover |author12=Carrie M. Upite |author13=Blair E. Witherington |title=Loggerhead Sea Turtle (''Caretta caretta'') 2009 Status Review Under the U.S. Endangered Species Act |publisher=Loggerhead Biological Review Team |year=2009 |url=http://library.seaturtle.org/4590 }}{{Dead link|date=June 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Along with the [[introduced species|introduced]] red fox (''[[Vulpes vulpes]]''), golden ghost crabs are significant as one of the main predators of [[sea turtle]] eggs and hatchlings in these regions.<ref name="gtcp11"/><ref name="troc"/><ref name="gtcp10"/><ref name="hattning">{{cite book|author =Karen Hattingh|title =Ningaloo Student Research Day 2010|chapter =Gnaraloo Turtle Conservation Program|publisher =Ningaloo Research Coordinating Committee|year =2010|pages =15–17|url =http://www.wamsi.org.au/sites/default/files/Ningaloo%20research%20day%20proceedings%202010.pdf|access-date =18 November 2013|archive-url =https://web.archive.org/web/20131202232610/http://www.wamsi.org.au/sites/default/files/Ningaloo%20research%20day%20proceedings%202010.pdf|archive-date =2 December 2013|url-status =dead}}</ref>
[[File:111206 Ghost crab predation Gnaraloo Bay Rookery.JPG|thumb|left|A golden ghost crab on a marked [[sea turtle]] nest]]
In the Gnaraloo Bay Rookery, where red fox populations have [[Red foxes in Australia|largely been kept in check]],<ref name="butcher">{{cite book|author =Mike Butcher|title =Gnaraloo Fox Control Program|publisher =Animal Pest Management Services|series =Annual Report on Fox Control at Gnaraloo Station|date =30 June 2011|url =http://www.gnaraloo.com/main/file/110822_G%20Fox%20Control%20Program%202010%2011%20APMS_0.pdf|access-date =17 November 2013|archive-url =https://web.archive.org/web/20160303230359/http://www.gnaraloo.com/main/file/110822_G%20Fox%20Control%20Program%202010%2011%20APMS_0.pdf|archive-date =3 March 2016|url-status =dead}}</ref> sea turtle eggs and hatchlings are mostly preyed upon by golden ghost crabs and, to a lesser extent, horned ghost crabs.<ref name="randall">{{cite book|author1=Martin Randall |author2=Stuart Bradley |editor =Raquel Carter|title =Ningaloo Marine Turtle Conference Exmouth|chapter =The Effects of Beach Topography on Turtle Hatchling Movements: By Tracking |publisher =World Wide Fund for Nature (WWF)|date=13 September 2003|page=20|url =http://awsassets.wwf.org.au/downloads/sp094_ningaloo_marine_turtle_conference_13sep03.pdf}}</ref><ref name="mack">{{cite book|author=Peter Mack|editor =Raquel Carter|title =Ningaloo Marine Turtle Conference Exmouth|chapter =Turtle Conservation work at Gnaraloo Bay|publisher =World Wide Fund for Nature (WWF)|date=13 September 2003|page=13|url =http://awsassets.wwf.org.au/downloads/sp094_ningaloo_marine_turtle_conference_13sep03.pdf}}</ref> Aside from directly preying on emerging hatchlings heading towards the water, there are also indications that golden ghost crabs actively burrow into nesting sites and feed on turtle eggs.<ref name="gtcp09"/><ref name="troc">{{cite thesis |author=Sabrina Trocini|title=Health assessment and hatching success of two Western Australian loggerhead turtle (''Caretta caretta'') populations|publisher=Murdoch University|year=2013|type=PhD|url=http://researchrepository.murdoch.edu.au/18114/2/02_Whole.pdf}}</ref>

In a 2010 assessment by the [[Gnaraloo Turtle Conservation Program]], golden ghost crabs were found to be responsible for the most number of sea turtle egg and hatchling predation. Golden ghost crabs disturbed 38% and 46.7% of the egg chambers in the total number of nests within the study area during day and night studies respectively. They were also recorded to be responsible for the predation of 12% of the total number of hatchlings that emerged. In comparison, red foxes were responsible for only 6.51% (day) and 9.5% (night) of nest disturbances, and only 0.3% of hatchling predation.<ref name="gtcp10">{{cite book |author1=Karen Hattingh |author2=Purusha Boelling |author3=Sergio Jacomy |author4=Amy James |author5=Jessica Leonard |author6=John Stuart |author7=Michael Williamson |title=Gnaraloo Day and Night Monitoring Final Report 2009/2010 |publisher=Gnaraloo Marine Turtle Research Program, Gnaraloo Station Trust |year=2010 |url=http://www.gnaraloo.com/main/file/100730_G%20Turtle%20report%2009%2010_1.pdf |access-date=17 November 2013 |archive-url=https://web.archive.org/web/20160304030852/http://www.gnaraloo.com/main/file/100730_G%20Turtle%20report%2009%2010_1.pdf |archive-date=4 March 2016 |url-status=dead }}</ref>

During the peak nesting season in 2010 to 2011, golden ghost crabs were also recorded to have disturbed 35%<ref group="note">Disturbed nests refer to ghost crab burrows being found in nests but with no evidence of egg mortality visible from the surface. They may not necessarily indicate predation as some nests with ghost crab burrows were still observed to successfully hatch</ref> of the nests and to have actively preyed upon another 38%,<ref group="note">Nest predation refers to ghost crab burrows being found in nests with clear evidence of egg mortality visible from the surface such as egg fragments, yolk, or an exposed egg chamber</ref> for a cumulative 73% of the nests affected.<ref name="gtcp11"/><ref name="hattning"/>

Areas with higher numbers of turtle nests also had higher numbers of ghost crabs, indicating a possible positive correlation between the two.<ref name="gtcp11">{{cite book |author1=Karen Hattingh |author2=Matt Boureau |author3=Marie Duffy |author4=Mark Wall |title=Gnaraloo Turtle Conservation Program – Final Report 10/11: Day monitoring program with Night checks and Crab burrow surveys |publisher=Gnaraloo Marine Turtle Research Program, Gnaraloo Station Trust |year=2011 |url=http://www.gnaraloo.com/main/file/110720_GTCP%20Report%202010%2011_1.pdf |access-date=17 November 2013 |archive-url=https://web.archive.org/web/20160304030858/http://www.gnaraloo.com/main/file/110720_GTCP%20Report%202010%2011_1.pdf |archive-date=4 March 2016 |url-status=dead }}</ref> The ghost crab population was highest during the summer seasons, and it is hypothesised that this might be because of greater food availability, as the summer tides leave a greater amount of debris on the beaches. However, gauging the true extent of the effects of golden ghost crabs on sea turtle hatchling and egg mortality still remains difficult, largely due to the fact that they usually flee at the presence of human observers and thus skew the data.<ref name="gtcp09"/><ref name="gtcp10"/> Nest monitoring with [[night vision device|night vision cameras]] has been proposed as a possible means of acquiring a more accurate assessment.<ref name="gtcp09"/>

Some methods for protecting the nests against golden ghost crabs have been proposed for trial in Gnaraloo. These include wire or plastic screens placed over the nests and continued human presence to discourage predators.<ref name="gtcp10"/>

==Distribution==
[[File:111210 Ghost crab duel Gnaraloo Bay Rookery.JPG|thumb|Antagonistic encounter between a golden ghost crab and a horned ghost crab (''[[Ocypode ceratophthalma|Ocypode&nbsp;ceratophthalma]]'')]]
Golden ghost crabs are [[endemism|endemic]] to the coast of Western Australia,<ref name="from">{{cite book|author1=Jane Fromont |author2=C. Hass |author3=L. Marsh |author4=G. Moore |author5=M. Salotti |author6=M. Titelius |author7=C. Whisson |title =Biodiversity of Marine Fauna on the Central West Coast|publisher =Strategic Research Fund for the Marine Environment, Western Australian Museum|series =SRFME Final Milestone Report –December 2006|year=2006|url =http://www.srfme.org.au/reports/Biodiversity_marinefauna-2006.pdf}}</ref> from [[Broome, Western Australia|Broome]] to [[Perth]].<ref name="sakai"/> They are one of five ghost crab species found in the Western Australian coast, the others being ''Ocypode ceratophthalma'', ''[[Ocypode cordimanus]]'', ''[[Ocypode fabricii]]'', and ''[[Ocypode pallidula]]''. Among these, ''Ocypode fabricii'' is also endemic to Australia (from [[Darwin, Northern Territory|Darwin]] to [[Shark Bay]]).<ref name="sakai"/>

Golden ghost crabs can easily be distinguished from all other species by their large size, their golden yellow colouration, and the rough tuberculation on their claws. The only similarly sized species in the region is the horned ghost crab, which are also easily distinguishable as they are the only ghost crab in Australia exhibiting spikes (exophthalmy) on the tips of their eyestalks. Younger individuals may be identified through the examination of their stridulating ridges and the shape of their gonopods.<ref name="sakai"/>

==Conservation==
Due to the limited range of golden ghost crabs in Western Australia, they are deemed vulnerable to large scale environmental disasters that might affect the region (like [[oil spill]]s).<ref name="kdav"/>

Like other ghost crabs, they are also strongly affected by human activity on their beach habitats, particularly by vehicles. In Western Australia, where driving [[off-road vehicle]]s are common recreational activities by locals and tourists, ghost crabs are often crushed inside their burrows due to the weight of the passing vehicles. This is believed to contribute to their very low populations (up to 90% lower) in beaches near the urban areas in southern Australia.<ref name="Buck">{{cite book|author=Ralf Buckley|editor =Ralf Buckley|title =Environmental Impacts of Ecotourism|chapter =Environmental Impacts of Motorized Off-highway Vehicles|publisher =CABI|year =2004|page=83|isbn =9780851998107|chapter-url =https://books.google.com/books?id=wueZG01A9YoC&q=ghost+crab+OHV+southern+australia&pg=PA88}}</ref><ref name="cater">{{cite book|author1=Carl Cater |author2=Ralf Buckley |author3=Robert Hales |author4=David Newsome |author5=Catherine Pickering |author6=Amanda Smith |editor =Kelly Van Asperen|title =High Impact Activities in Parks: Best management practice and future research|chapter =Environmental Impacts of Motorized Off-highway Vehicles|publisher =Sustainable Tourism Cooperative Research Centre|year =2008|isbn =9781920965723|url=http://researchrepository.murdoch.edu.au/2635/1/high_impact_activities_in_parks.pdf}}</ref>

Golden ghost crabs, however, remain abundant in places with little to no human habitation, particularly in beaches with restricted vehicular access (such as the [[Gnaraloo Station]]).<ref name="leeden">{{cite thesis |author= Cherie Louise Leeden |title=Quaternary coastal evolution adjacent to southern Ningaloo Reef, Western Australia: Implications for land use planning.|publisher=Curtin University of Technology|year=2003|url=http://ningaloo-atlas.org.au/sites/default/files/Leeden%20Honours%20thesis%202003.pdf}}</ref>

== See also ==
{{Portal|Crustaceans}}
*[[Threats to sea turtles]]
{{Clear}}

==Notes==
{{Reflist|group=note|2}}

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

==External links==
{{Commons category|Ocypode convexa}}
*[https://web.archive.org/web/20131127023752/http://www.gnaraloo.com/main/ Gnaraloo Station Official Website]
*[https://web.archive.org/web/20150610213846/http://www.arkive.org/silver-gull/larus-novaehollandiae/video-08a.html Video] of Silver Gulls (''[[Larus novaehollandiae]]'') stealing food from golden ghost crabs from [[ARKive]].

{{taxonbar|from=Q13908736}}

[[Category:Ocypodoidea]]
[[Category:Crustaceans described in 1824]]