Cherax quinquecarinatus
Encyclopedia
Cherax quinquecarinatus is a small freshwater crayfish
endemic to the south-west corner of Australia
. It is one of two species known as gilgie, or jilgi, which is a seasonal food source for people of the region. Gilgies are found throughout a biogeographically
isolated region of the coastal south of Western Australia
and significant in the ecology
of aquatic system
s of that bioregion.
. They vary in colour from light to black-brown.
Their heads have 5 keels, two pairs of spines at rostrum
and none on their telson
. Their chelipeds are rounded and narrow and are often speckled. While restricted to southwestern Western Australia
, it has the widest distribution in the biogeographic region. It is found in all habitats containing freshwater crayfish, congenors such as Cherax tenuimanus
(marron), or the genus Engaewa
.
The species has been traditionally hunted by tribe
s in the region. This involved an elaborate seasonal rituals relating to taboo
s of eating. It has been claimed that this was linked to an early form of environmentalism
and sustainability
. 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
group carried unique and particular oral tradition
s regarding this practice. Indigenous artwork has been shown to actually convey important information about different species and selective harvesting. The Nyungah people are also known to have caught and eaten the animal.
In Western Australia
, recreational fishing (marron
ing) will include gilgies in the catch, but it is not considered to be a commercial species.
It can survive periods of drought through a process called aestivation - 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
.
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
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 endemic 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
s and courses. The species is sensitive to pollutants such as petroleum products and organochlorines and is known to accumulate heavy metals
.
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
. 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
gardens in Western Australia. They enable ponds and pools to be self-sustaining.
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...
endemic to the south-west corner of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. It is one of two species known as gilgie, or jilgi, which is a seasonal food source for people of the region. Gilgies are found throughout a biogeographically
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
isolated region of the coastal south of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
and significant in the ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
of aquatic system
Aquatic ecosystem
An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems....
s of that bioregion.
Description
Reaching a maximum of 130 mm, C. quinquecarinatus is one of the smallest in the genus CheraxCherax
Cherax is the largest and most widespread genus of fully and partially aquatic crayfish in the Southern Hemisphere. Its members may be found in lakes, rivers and streams across most of Australia and New Guinea. In Australia the many species of Cherax are commonly known as yabbies...
. They vary in colour from light to black-brown.
Their heads have 5 keels, two pairs of spines at rostrum
Rostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
and none on their telson
Telson
The telson is the last division of the body of a crustacean. It is not considered a true segment because it does not arise in the embryo from teloblast areas as do real segments. It never carries any appendages, but a forked "tail" called the caudal furca is often present. Together with the...
. Their chelipeds are rounded and narrow and are often speckled. While restricted to southwestern Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
, it has the widest distribution in the biogeographic region. It is found in all habitats containing freshwater crayfish, congenors such as Cherax tenuimanus
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 River...
(marron), or the genus Engaewa
Engaewa
Engaewa is a genus of burrowing crayfish belonging to the family Parastacidae. There are five recognised species, all endemic to the high-rainfall zone of south-west Western Australia, from Dunsborough to Albany. They are all small , and found only in freshwater swamps and seepages...
.
The species has been traditionally hunted by tribe
Tribe
A tribe, viewed historically or developmentally, consists of a social group existing before the development of, or outside of, states.Many anthropologists use the term tribal society to refer to societies organized largely on the basis of kinship, especially corporate descent groups .Some theorists...
s in the region. This involved an elaborate seasonal rituals relating to taboo
Taboo
A taboo is a strong social prohibition relating to any area of human activity or social custom that is sacred and or forbidden based on moral judgment, religious beliefs and or scientific consensus. Breaking the taboo is usually considered objectionable or abhorrent by society...
s of eating. It has been claimed that this was linked to an early form of environmentalism
Environmentalism
Environmentalism is a broad philosophy, ideology and social movement regarding concerns for environmental conservation and improvement of the health of the environment, particularly as the measure for this health seeks to incorporate the concerns of non-human elements...
and sustainability
Sustainability
Sustainability is the capacity to endure. For humans, sustainability is the long-term maintenance of well being, which has environmental, economic, and social dimensions, and encompasses the concept of union, an interdependent relationship and mutual responsible position with all living and non...
. Family groups (moieties) would establish temporary claim to territory and lay fishtraps
Fishing net
A fishing net or fishnet is a net that is used for fishing. Fishing nets are meshes usually formed by knotting a relatively thin thread. Modern nets are usually made of artificial polyamides like nylon, although nets of organic polyamides such as wool or silk thread were common until recently and...
and use scoops
Billycan
A billycan, more commonly known simply as a billy or occasionally as a billy can , is a lightweight cooking pot which is used on a campfire or a camping stove.-Usage and etymology of the term:...
to gather marron and jilgi. Some tribes travelled great distances to join the hunt and each indigenous
Indigenous Australians
Indigenous Australians are the original inhabitants of the Australian continent and nearby islands. The Aboriginal Indigenous Australians migrated from the Indian continent around 75,000 to 100,000 years ago....
group carried unique and particular oral tradition
Oral tradition
Oral tradition and oral lore is cultural material and traditions transmitted orally from one generation to another. The messages or testimony are verbally transmitted in speech or song and may take the form, for example, of folktales, sayings, ballads, songs, or chants...
s regarding this practice. Indigenous artwork has been shown to actually convey important information about different species and selective harvesting. The Nyungah people are also known to have caught and eaten the animal.
In Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
, recreational fishing (marron
Marron
Marron is a name given to two closely related species of crayfish in Western Australia. Formerly considered a single species, it is now thought to comprise two species, the critically endangered Cherax tenuimanus, and the species which is outcompeting it, Cherax cainii.Marron make excellent eating,...
ing) will include 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 a process called aestivation - 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
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
.
The animal undergoes many moults
Ecdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
and these decrease with age. Sexual maturity can occur from two years and at half their fully mature size. Spawning
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
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 endemic 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
Water table
The water table is the level at which the submarine pressure is far from atmospheric pressure. It may be conveniently visualized as the 'surface' of the subsurface materials that are saturated with groundwater in a given vicinity. However, saturated conditions may extend above the water table as...
s and courses. The species is sensitive to pollutants such as petroleum products and organochlorines and is known to accumulate heavy metals
Heavy metals
A heavy metal is a member of a loosely-defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. Many different definitions have been proposed—some based on density, some on atomic number or atomic weight,...
.
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
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
. 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
Permaculture is an approach to designing human settlements and agricultural systems that is modeled on the relationships found in nature. It is based on the ecology of how things interrelate rather than on the strictly biological concerns that form the foundation of modern agriculture...
gardens in Western Australia. They enable ponds and pools to be self-sustaining.
See also
- Cherax destructor (common yabbyCommon yabbyThe common yabby, Cherax destructor, is an Australian freshwater crustacean in the Parastacidae family. It is listed as a vulnerable species of crayfish by the World Conservation Union , though the validity of this listing is questionable; wild yabby populations remain strong, and have expanded...
) - Cherax quadricarinatus (Australian red claw crayfish)
- Cherax tenuimanusCherax tenuimanusCherax 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 River...
(Margaret River marron or hairy marron)
External links
- Cherax quadricarinatus, Tree of Life Web ProjectTree of Life Web ProjectThe Tree of Life Web Project is an ongoing 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....
- Recreational fishing .gov.au
- Cherax tenuimanus-listing
- Standard 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)