Marron are native to the permanent rivers and streams in the south–west of Western Australia, between Harvey and Albany. Genetic variation exists with some river strains possessing very large claws, while others have 'hairy' tails. Following European settlement, Marron have been distributed well beyond their natural range, to the Hutt River in the North, near Esperance in the South, and as far east as Kangaroo Island in South Australia. It should be noted that the Marron is subject to continuing scientific study by Dr Chris Austin and co-workers at the Deakin University. Dr Austin's work, when published will considerably alter our understanding of the taxonomy of the Marron. (WA, SA (introduced)).Features:
Marron are the third largest freshwater crayfish in the world. Individual Marron have been recorded at over 2 kg in weight. They vary in colour from brown to jet-black with a cobalt blue hybrid farmed for the aquarium trade. Marron are distinguished from other freshwater crayfish by five ridges on the top of the carapace (head), three short pairs of spines on the rostrum and a pair of spines on the dorsal surface of the telson (top of the tail). Marron also possess large pincer-like chelipeds (claws).Ecology/Way of Life:
Marron live in fresh to brackish water (low salinity), preferring areas with sand and debris for protection. Unlike many other freshwater crayfish, Marron do not burrow, preferring to find refuge in sunken logs and other debris on the bottom of forest rivers. Marron generally mature at 2 to 3 years of age and mate in early spring. Females have oviduct pores at the base of the middle pair of walking legs, and males have their genital papillae on the closest pair of legs to the tail. The male deposits a spermatophore (sperm packet) between the female's legs and she incubates the eggs on pleopods under the tail for 3–4 months, the hatchlings are released in early summer.Interaction with Humans/Threats:
Marron have a reputation as being an excellent eating species with a large portion of its bodyweight being in the tail, which contains the edible meat. They have been exported to South Africa, Zimbabwe, United States, China, Japan and the Caribbean, with a thriving industry on South Australia's Kangaroo Island. Marron are usually farmed in semi-intensive ponds with some farmers stocking them with fish species to form a polyculture. Marron form the basis of a large recreational fishery in Western Australia. Stock levels fluctuate, with over-fishing causing the closure of the fishery in some years.Other Comments:
Cherax tenuimanus was named by Smith in 1912.Further Reading:
Western Australian Department of Fisheries. (2004). Identifying Freshwater Crayfish in South West WA. ttp://www.fish.wa.gov.au/docs/pub/IdCrayfish/index.php?0308
Crandall, K.A. & Fetzner, J.W. (2004). Crayfish Home Page. http://crayfish.byu.edu/
Lawrence, C. (1998). Rural Industries Australia. http://www.rirdc.gov.au/pub/handbook/marron.html
Morrissy, N.M & Lawrence, C.S. 2000. Genetic improvement of marron Cherax tenuimanus (Smith) and yabbies Cherax spp. in Western Australia. Aquaculture Research vol. 31 (1): 69 – 82.
Lawrence, C. (1995). Marron Cherax tenuimanus. Aquaculture WA brochure No 2, Fisheries Department of Western Australia, 4 p.
Morrissy, N.M. (1992). An introduction to marron and other freshwater crayfish farming in Western Australia. Fisheries Department of Western Australia. 36 p.
Text and Distribution map by Marios Vassiliou and Glen Whisson. Photograph by Sonja Gammeter and Andreas Frutiger.Sponsorship welcomed:
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