''Cherax'', commonly known as yabby/yabbies in Australia, is the most widespread

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of fully aquatic

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...

in the Southern Hemisphere. Various species of cherax may be found in both still and flowing bodies of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

across most of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

. Together with ''

Euastacus ''Euastacus'' is a genus of freshwater crayfish known as "spiny crayfish". They are found in the south-east of the Australian mainland, along with another genus of crayfish, ''Cherax''. Both genera are members of the family Parastacidae, a f ...

'', it is also the largest crayfish genus in the Southern Hemisphere.

Habitat

Members of the cherax genus can be found in

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

s, and

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...

s across most of Australia and New Guinea. The most common and widely distributed species in Australia is the

common yabby The common yabby (''Cherax destructor'') is an Australian freshwater crustacean in the Parastacidae family (biology), family. It is listed as a vulnerable species of crayfish by the International Union for Conservation of Nature (IUCN), though ...

(''C. destructor''). It is generally found in

lowland Upland and lowland are conditional descriptions of a plain based on elevation above sea level. In studies of the ecology of freshwater rivers, habitats are classified as upland or lowland. Definitions Upland and lowland are portions of ...

rivers and streams, lakes, swamps, and impoundments at low to medium altitude, largely within the

Murray–Darling Basin The Murray–Darling basin is a large geographical area in the interior of southeastern Australia, encompassing the drainage basin of the tributaries of the Murray River, Australia's longest river, and the Darling River, a right tributary of ...

. Common yabbies are found in many ephemeral waterways, and can survive dry conditions for long periods of time (at least several years) by 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. New Guinea is also home to the only known cave-living crayfish in the Southern Hemisphere, ''C. acherontis''.

Introduced

Some species are very colourful and sometimes seen in the freshwater aquarium trade.

Reproduction

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. Both sexes of ''Cherax'' are selective with copulation partners. Females tend to choose males with a larger central mass (abdomen and tail) and

cheliped A chela ()also called a claw, nipper, or pinceris a pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are called chelipeds. ...

. 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. 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 profitable offspring. During the fight both release urine. The female’s release of urine triggers a sexual response from the male. 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. Once the female has allowed the male to deposit its sperm. The male will position itself on its back and deposit its sperm. 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. Female ''C. dispar'' uses honest signalling of strength meaning the size of their chelae is a good indication to other ''C. dispar'' about that individual's strength. Individuals possessing larger chelae engage in more agonistic encounters and are also more likely to win. In a study of female C''. dispar'' chelae strength, they found that chelae size also indirectly indicated the dominance of the female because of its honest indication of strength.

Species

The genus contains 59 species: *''

Cherax acherontis ''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 ...

'' Patoka, Bláha & Kouba, 2017 *''

Cherax albertisii ''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 Au ...

'' Nobili, 1899 *'' Cherax albidus'' Clarke, 1936 *'' Cherax angustus'' *'' Cherax aruanus'' Roux, 1911 *''

Cherax austini ''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 Aus ...

'' Coughran & Hobson, 2012 *'' Cherax barretti'' Clark, 1941 *'' Cherax bicarinatus'' (Gray, 1845) *''

Cherax boesemani ''Cherax boesemani'' is a species of crayfish from West Papua in Indonesia (Ajamaru Lakes and the Ajamaru River, which belong to the Kais River drainage and Kepala Burung or Vogelkop Peninsulas). It is popular as a freshwater aquarium pet ac ...

'' Lukhaup & Pekny, 2008 *'' Cherax boschmai'' Holthuis, 1949 *''

Cherax buitendijkae ''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 Aus ...

'' Holthuis, 1949 *''

Cherax cainii ''Cherax cainii'', known as the smooth marron, is one of two species of crayfish that are endemic in Southwestern Australia known as marron. It occupies a range extending from around Hutt River in the north west to around Esperance in the sou ...

'' Austin, 2002 *'' Cherax cairnsensis'' Riek, 1969 *'' Cherax cartalacoolah'' Short, 1993 *''

Cherax cid ''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 Aus ...

'' Coughran & Furse, 2012 *'' Cherax communis'' Holthuis, 1949 *'' Cherax crassimanus'' Riek, 1967 *'' Cherax cuspidatus'' Riek, 1969 *'' Cherax davisi'' Clark, 1941 *'' Cherax depressus'' Riek, 1951 *''

Cherax destructor The common yabby (''Cherax destructor'') is an Australian freshwater crustacean in the Parastacidae family. It is listed as a vulnerable species of crayfish by the International Union for Conservation of Nature (IUCN), though wild yabby popul ...

'' Clark, 1936 *'' Cherax dispar'' Riek, 1951 *''

Cherax esculus ''Cherax'', commonly known as yabby/yabbies in Australia, is the most widespread genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy o ...

'' Riek, 1956 *'' Cherax gherardii'' Patoka, Bláha & Kouba, 2015 *'' Cherax glaber'' Riek, 1967 *''

Cherax glabrimanus ''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 Au ...

'' Riek, 1967 *''

Cherax gladstonensis ''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 Aus ...

'' Riek, 1969 *'' Cherax holthuisi'' Lukhaup & Pekny, 2006 *''

Cherax leckii ''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 ...

'' Coughran, 2005 *'' Cherax longipes'' Holthuis, 1949 *''

Cherax lorentzi ''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 ...

'' Roux, 1911 *'' Cherax minor'' Holthuis, 1996 *'' Cherax misolicus'' Holthuis, 1949 *'' Cherax monticola'' Holthuis, 1950 *'' Cherax murido'' Holthuis, 1949 *'' Cherax neocarinatus'' Riek, 1967 *'' Cherax neopunctatus'' Riek, 1969 *'' Cherax nucifraga'' Short, 1991 *''

Cherax pallidus ''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 ...

'' Holthuis, 1949 *'' Cherax paniaicus'' Holthuis, 1949 *''

Cherax papuanus ''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 Aus ...

'' Holthuis, 1949 *''

Cherax parvus ''Cherax parvus'' is a species of crayfish in the family Parastacidae. It is only known from its type locality – the Upper Tully River catchment in the Cardwell Range of north-eastern Queensland – and is listed as data deficient on the IUCN ...

'' Short & Davie, 1993 *'' Cherax peknyi'' Lukhaup & Herbert, 2008 *'' Cherax plebejus'' (Hess, 1865) *'' Cherax preissii'' (Erichson, 1846) *''

Cherax pulcher ''Cherax pulcher'' is a species of crayfish from West Papua in Indonesia. It is popular as a freshwater aquarium species across Asia, Europe, and North America.Patoka, J., Kalous, L., & Kopecký, O. (2015). Imports of ornamental crayfish: the ...

'' Lukhaup, 2015 *'' Cherax punctatus'' Clark, 1936 *''

Cherax quadricarinatus ''Cherax quadricarinatus'' (known by several common names, including Australian red claw crayfish, Queensland red claw, redclaw, tropical blue crayfish, freshwater blueclaw crayfish) is an Australian freshwater crayfish. Distribution and ecol ...

'' (von Martens, 1868) *'' Cherax quinquecarinatus'' (Gray, 1845) *'' Cherax rhynchotus'' Riek, 1951 *''

Cherax robustus ''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 ...

'' Riek, 1951 *'' Cherax rotundus'' Clark, 1941 *'' Cherax setosus'' (Riek, 1951) *'' Cherax snowden'' Lukhaup, Panteleit & Schrimpf, 2015 *''

Cherax solus ''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 ...

'' Holthuis, 1949 *''

Cherax tenuimanus ''Cherax tenuimanus'', known as the hairy marron or Margaret River marron, is one of two species of crayfish in Southwestern Australia known as marron. It occupies a narrow range within the southwestern biogeographical region of Margaret Rive ...

'' (Smith, 1912) *'' Cherax urospinosus'' Riek, 1969 *'' Cherax wagenknechtae'' Eprilurahman / Lukhaup, 2022 *'' Cherax wasselli'' Riek, 1969

References

* {{Taxonbar, from=Q2702517 Parastacidae Decapod genera