Cherax cainii

{{Short description|Species of crayfish}}

{{Use Australian English|date=April 2021}}

{{Speciesbox

| image = Cherax_cainii.jpg

| status =

LC| status_system =

IUCN3.1

| status_ref = {{cite iucn |author=Austin, C.M. |author2=Bunn, J. |date=2010 |title=Cherax cainii |volume=2010 |page=e.T153634A4523609 |doi=10.2305/IUCN.UK.2010-3.RLTS.T153634A4523609.en |access-date=19 November 2021}}

| genus = Cherax

| species = cainii

| authority = Austin and Ryan 2002

}}

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 south east of Western Australia.{{Cite iucn | author = C. M. Austin | author2 = J. Bunn | title = Cherax tenuimanus | volume = 2010 | page = e.T4618A11033949 | date = 2010 | doi = 10.2305/IUCN.UK.2010-3.RLTS.T4618A11033949.en }}{{cite web|url=https://rivers.dwer.wa.gov.au/species/cherax-cainii/|title=Smooth marron - Cherax cainii|access-date=17 April 2021|work=Healthy Rivers|publisher=Department of Water and Environmental Regulation|year=2021}} The species is also now found in variety of artificial and natural fresh water bodies of Queensland, South Australia, Victoria and New South Wales in Australia. It has also been introduced to other countries including North America, Chile, South Africa, Zambia, Japan and New Zealand as a part of commercial aquaculture schemes.{{cite web|url=https://www.cabi.org/isc/datasheet/89136|title=Cherax cainii (smooth marron)|access-date=17 April 2021|work=Invasive Species Compendium|publisher=

CAB International}}