Critically Endangered
Cherax tenuimanus
Cherax tenuimanus
Cherax tenuimanus is a crayfish in the family Parastacidae (order Decapoda), recorded as Critically Endangered.
Appearance
The hairy marron ranges in colour from olive green to brown to black, with females sometimes having red or purple patches on their undersides.
Adult hairy marrons grow to between 300 and 400 mm with a body consisting of a head and thorax that are protected by a carapace.
Range and habitat
The hairy marron lives in exclusively freshwater habitats, specifically in clear, oxygen-rich water in the Margaret River in Southwestern Australia. Its range has become limited to three major pools in the upper portion of the river due to competition with the smooth marron. Cherax tenuimanus, known as the hairy marron or Margaret River marron, is one of two species of crayfish in Southwestern Australia known as marron.
Efforts were also undertaken between 2013 and 2017 to regularly remove smooth marron from the few pools inhabited by hairy marron, but it was eventually decided that these fish outs were not having a pronounced enough effect to preserve wild populations.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
The hairy marron is an omnivore whose diet mainly consists of small invertebrates, fish eggs and larvae, and algae. It is also a cannibal that will potentially eat its own young.
Hairy marrons begin to mate when they reach sexual maturity during the second and third years of their lives, with their mating season occurring between July and October. The eggs are then held under the female's tail for several weeks, hatching at or just after the end of the mating season, and the juveniles remain on the mother's swimmerets until they have finished consuming their yolk sacs and are mature enough to feed on their own, that is usually by November or December.
In crisis
It is currently listed as critically endangered on the IUCN Red List, because of the threat from the smooth marron, Cherax cainii, that was introduced to its habitat. Conservation efforts have now turned toward expanding the captive breeding program and finding other sites where the captive marron could potentially be reintroduced to native water systems.
Cherax tenuimanus is Critically Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Cherax tenuimanus, Wikidata item Q4347707. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
