View source for Cherax

{{Short description|Genus of crayfishes}}
{{Use Australian English|date=May 2021}}
{{Use dmy dates|date=May 2021}}
{{Automatic taxobox
| image = Cherax papuanus.jpg
| image_caption = ''[[Cherax papuanus]]''
| taxon = Cherax
| authority = [[Wilhelm Ferdinand Erichson|Erichson]], 1846
| type_species = ''[[Cherax preissii|Astacus preissii]]''
| type_species_authority = Erichson, 1846
| range_map = Cherax distribution.svg
}}

'''''Cherax''''', commonly known as '''yabby'''/'''yabbies''' in Australia, is the most widespread [[genus]] of fully aquatic [[crayfish]] in the [[Southern Hemisphere]]. Various species of cherax may be found in both still and flowing bodies of [[freshwater]] across most of [[Australia]] and [[New Guinea]]. Together with ''[[Euastacus]]'', it is also the largest crayfish genus in the Southern Hemisphere.

==Habitat==
Members of the cherax genus can be found in [[lake]]s, [[river]]s, and [[stream]]s across most of Australia and New Guinea.<ref>{{cite journal |first1=D. H. N. |last1=Munasinghe |first2=C. P. |last2=Burridge  |first3=C. M. |last3=Austin |year=2004 |title=The systematics of freshwater crayfish of the genus ''Cherax'' Erichson (Decapoda: Parastacidae) in eastern Australia re-examined using nucleotide sequences from ''12S'' rRNA and ''16S'' rRNA genes |journal=Invertebrate Systematics |volume=18 |issue=2 |pages=215–225 |url=https://www.researchgate.net/publication/225083275 |format=[[Portable Document Format|PDF]] |doi=10.1071/IS03012 |name-list-style=amp |via=ResearchGate |url-access=registration}}</ref>

The most common and widely distributed species in Australia is the [[common yabby]] (''C. destructor'').  It is generally found in [[upland and lowland (freshwater ecology)|lowland]] rivers and streams, lakes, swamps, and impoundments at low to medium altitude, largely within the [[Murray–Darling Basin]]. Common yabbies are found in many ephemeral waterways, and can survive dry conditions for long periods of time (at least several years) by [[aestivation|aestivating]] (lying dormant) in burrows sunk deep into muddy creek and swamp beds.

In New Guinea, ''Cherax'' crayfish are found widely in rivers, streams, and lakes, with a particularly high diversity in the [[Paniai Lakes]].<ref>{{cite report |first1=Dan A. |last1=Polhemus |first2=Ronald A. |last2=Englund |first3=Gerald R. |last3=Allen |title=Freshwater Biotas of New Guinea and Nearby Islands: Analysis of Endemism |url=http://pbs.bishopmuseum.org/pdf/ci-png.pdf |publisher=Bernice Pauahi Bishop Museum, Conservation International |year=2004 |name-list-style=amp}}</ref> New Guinea is also home to the only known [[Troglobite|cave-living]] crayfish in the Southern Hemisphere, ''C. acherontis''.<ref name=Patoka2017>{{cite journal |last1=Patoka |first1=Jiří |last2=Bláha |first2=Martin |last3=Kouba |first3=Antonín |title=''Cherax acherontis'' (Decapoda: Parastacidae), the first cave crayfish from the Southern Hemisphere (Papua Province, Indonesia)|journal=[[Zootaxa]] |volume=4363 |issue=1 |pages=137–144 |doi=10.11646/zootaxa.4363.1.7 |year=2017|pmid=29245414 }}</ref>

===Introduced===
Some species are very colourful and sometimes seen in the freshwater aquarium trade.<ref name=Blaszczak2015>{{cite magazine |title=Mysterious beautiful blue crayfish is new species from Indonesia |magazine=[[New Scientist]] |date=2015-05-13 |access-date=2015-05-28 |url=https://www.newscientist.com/article/dn27517-mysterious-beautiful-blue-crayfish-is-new-species-from-indonesia.html#.VWecmaZ7nVA |first=Agata |last=Blaszczak-Boxe |issue=3021}}</ref>

==Reproduction==
{{Clarify|date=November 2021 |reason=Is this all ''Cherax'', or just ''C. dispar''?}}
The mating season for ''Cherax'' is during early spring. After fertilisation, eggs develop inside the mother's body for 4 to 6 weeks. After that period, the eggs transition to the outside of the mother's body and rest on the female's tail. Then the eggs continue to develop and hatch in spring.<ref>{{cite web |title=Crayfish |url=https://www.dept.psu.edu/nkbiology/naturetrail/speciespages/crayfish.htm |website=www.dept.psu.edu |access-date=27 May 2022 |archive-date=18 July 2022 |archive-url=https://web.archive.org/web/20220718180424/https://www.dept.psu.edu/nkbiology/naturetrail/speciespages/crayfish.htm |url-status=dead }}</ref>
 
[[File:Yabbies in shallow water During Spring001.jpg|thumb|Yabbies can inhabit shallow creeks during the wet season and burying themselves during droughts]]
Both sexes of ''Cherax'' are selective with copulation partners. Females tend to choose males with a larger central mass (abdomen and tail) and [[cheliped]]. Males tend to select copulation partners who have larger body sizes and are virgins. Opposed to females who were more dominant or had symmetrical chelipeds.<ref>{{cite journal |last1=Aquiloni |first1=L. |last2=Gherardi |first2=F. |year=2008 |title=Mutual mate choice in crayfish: Large body size is selected by both sexes, virginity by males only |journal=[[Journal of Zoology]] |volume=274 |issue=2 |pages=171–179 |doi=10.1111/j.1469-7998.2007.00370.x |name-list-style=amp|hdl=2158/252681 |s2cid=84513148 |hdl-access=free }}</ref>

As part of a mating/copulation ritual, males and females fight each other. This allows the female to test the strength of the male to determine if they will produce viable offspring.<ref name="Berry & Breithaupt, 2010">{{cite journal |last1=Berry |first1=Fiona C. |last2=Breithaupt |first2=Thomas |year=2010 |title=To signal or not to signal? Chemical communication by urine-borne signals mirrors sexual conflict in crayfish |journal=[[BMC Biology]] |volume=8 |issue=1 |page=25 |doi=10.1186/1741-7007-8-25 |pmid=20353555 |name-list-style=amp|pmc=2867775 |doi-access=free }}</ref> During the fight, both release urine. The female's release of urine triggers a sexual response from the male.<ref name="Berry & Breithaupt, 2010"/> The male's release of urine is an aggressive response towards the fight with the female. When the male smells the female's urine, it will stop releasing its own, hoping the female will allow them to copulate.{{citation needed|date=May 2021}}

Once the female allows it, the male will position itself on its back, and deposit its sperm.<ref>{{cite journal |last1=Barki |first1=Assaf |last2=Karplus |first2=Ilan |year=1999 |title=Mating Behavior and a Behavioral Assay for Female Receptivity in the Red-claw Crayfish ''Cherax quadricarinatus'' |journal=[[Journal of Crustacean Biology]] |volume=19 |issue=3 |pages=493–497 |doi=10.2307/1549258 |jstor=1549258 |name-list-style=amp|doi-access=free }}</ref> Unlike other crayfish species, the ''Cherax dispar'' does not use its cheliped to cage females during copulation. It is mainly used during mating when the males and females fight.

==Behaviour==
In instances when displaying males have chelae of a similar size, they will engage in combat and those with the greater chelae closing force will win.<ref name="Bywater et al, 2008">{{cite journal |last1=Bywater |first1=C. L. |last2=Angilletta |first2=M. J. |last3=Wilson |first3=R. S. |year=2008 |title=Weapon Size Is a Reliable Indicator of Strength and Social Dominance in Female Slender Crayfish (''Cherax dispar'') |journal=[[Functional Ecology (journal)|Functional Ecology]] |volume=22 |issue=2 |pages=311–316 |name-list-style=amp |doi=10.1111/j.1365-2435.2008.01379.x|doi-access=free }}</ref>

Female ''C. dispar'' uses [[honest signal]]ling of strength, meaning the size of their chelae is a good indication to other ''C. dispar'' about that individual's strength.<ref name="Bywater et al, 2008"/> Individuals possessing larger chelae engage in more agonistic encounters and are also more likely to win.<ref name="Bywater et al, 2008"/> In a study of female C''. dispar'' chelae strength, researchers found that chelae size also indirectly indicated the dominance of the female because of its honest indication of strength.<ref name="Bywater et al, 2008"/>

==Species==
[[File:Cherax Blue moon.jpg|thumb|Cherax "Blue Moon" which could be ''C. boesemani'' or ''C. holthuisi'']]
The genus contains at least 60 species:<ref>{{cite web |url=http://iz.carnegiemnh.org/crayfish/NewAstacidea/genus.asp?g=Cherax |title=Genus ''Cherax'' Erichson, 1846 |work=Crayfish Taxon Browser |last=Fetzner |first=James W. Jr. |publisher=[[Carnegie Museum of Natural History]] |access-date=2015-11-24 |date=2010-01-11 |archive-url=https://web.archive.org/web/20150402203502/http://iz.carnegiemnh.org/crayfish/NewAstacidea/genus.asp?g=Cherax |archive-date=2015-04-02 |url-status=dead}}</ref><ref name="ITIS">{{ITIS |id=1133542 |taxon=''Cherax''}}</ref>

{{div col|colwidth=24em}}
*''[[Cherax acherontis]]'' <small>Patoka, Bláha & Kouba, 2017</small><ref name=Patoka2017/>
*''[[Cherax albertisii]]'' <small>Nobili, 1899</small>
*''[[Cherax albidus]]'' <small>Clarke, 1936</small>
*''[[Cherax alyciae]]'' <small>Lukhaup, Eprilurahman & von Rintelen, 2018</small>
*''[[Cherax aruanus]]'' <small>Roux, 1911</small>
*''[[Cherax austini]]'' <small>Coughran & Hobson, 2012</small>
*''[[Cherax barretti]]'' <small>Clark, 1941</small>
*''[[Cherax bicarinatus]]'' <small>(Gray, 1845)</small>
*''[[Cherax boesemani]]'' <small>Lukhaup & Pekny, 2008</small>
*''[[Cherax boschmai]]'' <small>Holthuis, 1949</small>
*''[[Cherax buitendijkae]]'' <small>Holthuis, 1949</small>
*''[[Cherax cainii]]'' <small>Austin, 2002</small>
*''[[Cherax cairnsensis]]'' <small>Riek, 1969</small>
*''[[Cherax cartalacoolah]]'' <small>Short, 1993</small>
*''[[Cherax cid]]'' <small>Coughran & Furse, 2012</small>
*''[[Cherax communis]]'' <small>Holthuis, 1949</small>
*''[[Cherax crassimanus]]'' <small>Riek, 1967</small>
*''[[Cherax cuspidatus]]'' <small>Riek, 1969</small>
*''[[Cherax davisi]]'' <small>Clark, 1941</small>
*''[[Cherax depressus]]'' <small>Riek, 1951</small>
*''[[Cherax destructor]]'' <small>Clark, 1936</small>
*''[[Cherax dispar]]'' <small>Riek, 1951</small>
*''[[Cherax esculus]]'' <small>Riek, 1956</small>
*''[[Cherax gherardii]]'' <small>Patoka, Bláha & Kouba, 2015</small><ref>{{cite journal |first1=Jiří |last1=Patoka |first2=Martin |last2=Bláha |first3=Antonín |last3=Kouba |name-list-style=amp |year=2015 |title=''Cherax'' (''Astaconephrops'') ''gherardii'', a new crayfish (Decapoda: Parastacidae) from West Papua, Indonesia |journal=[[Zootaxa]] |volume=3964 |issue=5 |pages=526–536 |doi=10.11646/zootaxa.3964.5.2 |pmid=26249463}}</ref><ref name="Patoka_2015"/>
*''[[Cherax glaber]]'' <small>Riek, 1967</small>
*''[[Cherax glabrimanus]]'' <small>Riek, 1967</small>
*''[[Cherax gladstonensis]]'' <small>Riek, 1969</small>
*''[[Cherax holthuisi]]'' <small>Lukhaup & Pekny, 2006</small>
*''[[Cherax leckii]]'' <small>Coughran, 2005</small>
*''[[Cherax longipes]]'' <small>Holthuis, 1949</small>
*''[[Cherax lorentzi]]'' <small>Roux, 1911</small>
*''[[Cherax minor]]'' <small>Holthuis, 1996</small>
*''[[Cherax misolicus]]'' <small>Holthuis, 1949</small>
*''[[Cherax monticola]]'' <small>Holthuis, 1950</small>
*''[[Cherax murido]]'' <small>Holthuis, 1949</small>
*''[[Cherax neocarinatus]]'' <small>Riek, 1967</small>
*''[[Cherax neopunctatus]]'' <small>Riek, 1969</small>
*''[[Cherax nucifraga]]'' <small>Short, 1991</small>
*''[[Cherax pallidus]]'' <small>Holthuis, 1949</small>
*''[[Cherax paniaicus]]'' <small>Holthuis, 1949</small>
*''[[Cherax papuanus]]'' <small>Holthuis, 1949</small>
*''[[Cherax parvus]]'' <small>Short & Davie, 1993</small>
*''[[Cherax peknyi]]'' <small>Lukhaup & Herbert, 2008</small>
*''[[Cherax plebejus]]'' <small>(Hess, 1865)</small>
*''[[Cherax preissii]]'' <small>(Erichson, 1846)</small> syn. ''Cherax angustus'' <small>McCulloch, 1914</small> 
*''[[Cherax pulcher]]'' <small>Lukhaup, 2015</small><ref name=Blaszczak2015/>
*''[[Cherax punctatus]]'' <small>Clark, 1936</small>
*''[[Cherax quadricarinatus]]'' <small>(von Martens, 1868)</small>
*''[[Cherax quinquecarinatus]]'' <small>(Gray, 1845)</small>
*''[[Cherax rhynchotus]]'' <small>Riek, 1951</small>
*''[[Cherax robustus]]'' <small>Riek, 1951</small>
[[File:Cherax robustus.jpg|thumb|'''''C. robustus''''']]
*''[[Cherax rotundus]]'' <small>Clark, 1941</small>
*''[[Cherax setosus]]'' <small>(Riek, 1951)</small>
*''[[Cherax snowden]]'' <small>Lukhaup, Panteleit & Schrimpf, 2015</small><ref>{{cite magazine |title=New species of crayfish named after Edward Snowden |magazine=[[Time (magazine)|Time]] |date=2015-08-25 |access-date=2015-08-25 |url=https://time.com/4010078/crayfish-edward-snowden/ |first=Eliana |last=Dockterman}}</ref> syn. ''Cherax subterigneus''<ref name="Patoka_2015">{{cite journal |first1=Jiří |last1=Patoka |first2=Martin |last2=Bláha  |first3=Antonín |last3=Kouba |name-list-style=amp |year=2015 |title=''Cherax'' (''Cherax'') ''subterigneus'', a new crayfish (Decapoda: Parastacidae) from West Papua, Indonesia |journal=[[Journal of Crustacean Biology]] |volume=35 |issue=6 |pages=830–838 |doi=10.1163/1937240x-00002377 |doi-access=free }}</ref> 
*''[[Cherax solus]]'' <small>Holthuis, 1949</small>
*''[[Cherax tenuimanus]]'' <small>(Smith, 1912)</small>
*''[[Cherax urospinosus]]'' <small>Riek, 1969</small>
*''[[Cherax wagenknechtae]]'' <small>/Lukhaup,Eprilurahman  2022</small>
*''[[Cherax wasselli]]'' <small>Riek, 1969</small>
*''[[Cherax woworae]]'' <small>Patoka, Akmal, Bláha & Kouba, 2023</small> 
*''[[Cherax pulverulentus]]'' <small>Patoka, Akmal, Bláha, & Kouba, 2025</small><ref>{{Cite journal |last=Patoka |first=Jiří |last2=Akmal |first2=Surya Gentha |last3=BláHa |first3=Martin |last4=Kouba |first4=AntoníN |date=2025-01-09 |title=Cherax pulverulentus, a new freshwater crayfish (Decapoda: Parastacidae) from Southwest Papua Province, Indonesia |url=https://mapress.com/zt/article/view/zootaxa.5566.3.4 |journal=Zootaxa |volume=5566 |issue=3 |pages=522–534 |doi=10.11646/zootaxa.5566.3.4 |issn=1175-5334|url-access=subscription }}</ref>
{{Div col end}}

==References==
{{Reflist|32em}}

{{Taxonbar|from=Q2702517}}
{{Authority control}}

[[Category:Parastacidae]]
[[Category:Decapod genera]]