''Cherax preissii'', the common koonac, is a

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 ...

n freshwater

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

in the

Parastacidae The Parastacidae are the family of freshwater crayfish found in the Southern Hemisphere. The family is a classic Gondwana-distributed taxon, with extant members in South America, Madagascar, Australia, New Zealand, and New Guinea, and extinct ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

. Its

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contra ...

of "

koonac ''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 A ...

" is also applied to another Western Australian ''

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 A ...

'' species of crustacean ''C. glaber'', the "glossy koonac", which is restricted to a much smaller region of WA. Koonacs can grow up to 20 cm and may be coloured black and red, dark brown, or bluish black. They have broad, serrated claws and four keels on the head, two of which are prominent.

Ecology

Koonacs are endemic to the southwest of Western Australia, in wetlands, permanent and seasonal waterways, and farm dams. They are able to survive seasonal dryness for several months by digging burrows. Although they are rated as "least concern" on the IUCN redlist, local populations may be under threat by introduced eastern states yabbies such as ''

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 popula ...

'' and ''

Cherax albidus ''Cherax albidus'', commonly known as the white yabby, is an Australian freshwater crustacean in the Parastacidae family, found primarily in Western Australian agricultural dams, creeks and other small bodies of water. It receives the name of t ...

'' through competition for food and habitat.

Catching

Although catching koonacs is not seasonally restricted, fishing for

marron Marron is a name given to two closely related species of crayfish in Western Australia. Formerly considered a single species, it is now recognised as comprising two species, the critically endangered ''Cherax tenuimanus ''Cherax tenuimanu ...

is. The rules for fishing marron should be taken into account when fishing for koonacs, as this might involve the use of equipment (e.g. traps) that is illegal in marron-inhabited areas.

References

{{Taxonbar, from=Q20086316 Freshwater crustaceans of Western Australia Crustaceans described in 1846 Parastacidae Endemic fauna of Southwest Australia