''Cherax quinquecarinatus'' is a small freshwater

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 ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the south-west corner 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 ...

. It is one of two species known as gilgie, or jilgi, which is a

seasonal food Seasonal food refers to the times of year when the harvest or the flavour of a given type of food is at its peak. This is usually the time when the item is harvested, with some exceptions; an example being sweet potatoes which are best eaten qui ...

source for people of the region. Gilgies are found throughout a

biogeographically Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities of ...

isolated region of the coastal south of

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

and are significant in the

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

of aquatic systems of that

bioregion A bioregion is an ecologically and geographically defined area that is smaller than a biogeographic realm, but larger than an ecoregion or an ecosystem, in the World Wide Fund for Nature classification scheme. There is also an attempt to use the ...

Description

Reaching a maximum of 130 mm, ''C. quinquecarinatus'' is one of the smallest in the genus ''

Cherax ''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 ...

''. They vary in colour from light to black-brown. Their heads have five keels (as inferred by the

epithet An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...

), two pairs of spines at

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

, and none on their

telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...

s. Their

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. ...

s are rounded and narrow and are often speckled. While restricted to southwestern

, it has the widest distribution in the biogeographic region. It is found in all habitats containing freshwater crayfish, congeners such as ''

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 ...

'' (marron), or the genus ''

Engaewa ''Engaewa'' is a genus of burrowing crayfish belonging to the family Parastacidae. There are five recognised species, all endemism, endemic to the high-rainfall zone of south-west Western Australia, from Dunsborough, Western Australia, Dunsboro ...

''. The species has been traditionally hunted by

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English language, English is in the discipline of anthropology. This definition is contested, in p ...

s in the region. This involved elaborate seasonal rituals relating to

taboo A taboo or tabu is a social group's ban, prohibition, or avoidance of something (usually an utterance or behavior) based on the group's sense that it is excessively repulsive, sacred, or allowed only for certain persons.''Encyclopædia Britannica ...

s of eating. This was claimed to have been linked to an early form of

environmentalism Environmentalism or environmental rights is a broad philosophy, ideology, and social movement regarding concerns for environmental protection and improvement of the health of the environment, particularly as the measure for this health seek ...

and

sustainability Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livi ...

. Family groups ( moieties) would establish temporary claim to territory and lay fishtraps and use scoops to gather marron and jilgi. Some tribes travelled great distances to join the hunt and each

indigenous Indigenous may refer to: *Indigenous peoples *Indigenous (ecology), presence in a region as the result of only natural processes, with no human intervention *Indigenous (band), an American blues-rock band *Indigenous (horse), a Hong Kong racehorse ...

group carried unique and particular

oral tradition Oral tradition, or oral lore, is a form of human communication wherein knowledge, art, ideas and cultural material is received, preserved, and transmitted orally from one generation to another. Vansina, Jan: ''Oral Tradition as History'' (1985 ...

s regarding this practice. Indigenous artwork has been shown to actually convey important information about different species and selective harvesting. The

Noongar The Noongar (, also spelt Noongah, Nyungar , Nyoongar, Nyoongah, Nyungah, Nyugah, and Yunga ) are Aboriginal Australian peoples who live in the south-west corner of Western Australia, from Geraldton on the west coast to Esperance on the so ...

people are also known to have caught and eaten the animal. In Western Australia, recreational fishing (marroning) includes gilgies in the catch, but it is not considered to be a commercial species.

Ecology

The gilgie lives in permanent and temporary water courses in the south of Western Australia. It can survive periods of drought through

aestivation Aestivation ( la, aestas (summer); also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and ...

- burrowing down and entering a state of dormancy. They are widely found within the region, having a greater range of environments. These can include permanent lakes and areas receiving water for 5–7 months of the year. It lives in complex and narrow environments, such as silty river beds between fallen trees, feeding on decaying organic matter and receiving protection from

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

. The animal undergoes many moults and these decrease with age. Sexual maturity can occur from two years and at half their fully mature size.

Spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquati ...

occurs from late winter to early summer. Their conservation is that of all the freshwater crayfish species of the South West, recognised as having a high degree of importance due to the long-term isolation of the bioregion. However, protection of the two

genera is usually focused on the commercial species. Few studies have been made to the specific threat. The region has undergone extensive logging and intensive cultivation which are known to have impacted upon the

water table The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated. T ...

s and courses. The species is sensitive to pollutants such as petroleum products and

organochlorines An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlo ...

and is known to accumulate

heavy metals upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as ...

. The species is assumed to have an integral role, through the consumption of decaying organic matter, in the ecology of its region and contributing to the

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...

. High sensitivity to toxins and pollutants has been seen as an indicator of the presence of these within a habitat. Some populations have been exposed to porcelain disease ('' Thelohania'') and the introduction of crayfish diseases threaten entire populations. The gilgie is used in

permaculture Permaculture is an approach to land management and settlement design that adopts arrangements observed in flourishing natural ecosystems. It includes a set of design principles derived using whole-systems thinking. It applies these principle ...

gardens in Western Australia. They enable ponds and pools to be self-sustaining.

References

External links

''Cherax quadricarinatus''

Tree of Life Web Project The Tree of Life Web Project is an Internet project providing information about the diversity and phylogeny of life on Earth. This collaborative peer reviewed project began in 1995, and is written by biologists from around the world. The site h ...

Recreational fishing .gov.au''Cherax tenuimanus''-listingStandard Fish Names in Australia (commercial species)
Yabby: ''Cherax spp.'' except ''C. quadricarinatus'', ''C. cainii'' & ''C. tenuimanus'', Parastacidae (freshwater crayfish, yabbies) inconclusive.
Chapt. 5.3.5 (about Marroning)
{{Taxonbar, from=Q5091851 Parastacidae Freshwater crustaceans of Australia Crustaceans described in 1845 Taxa named by John Edward Gray Endemic fauna of Southwest Australia Edible crustaceans

Description

Ecology

See also

References

External links