Euastacus spinifer
Euastacus spinifer is a species of freshwater crayfish endemic to Australia that belongs to the family Parastacidae.
Euastacus spinifer | |
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Species: | E. spinifer |
Binomial name | |
Euastacus spinifer (Heller, 1865) | |
Range of Euastacus spinifer (orange) in Australia |
Appearance
Morphological variation is observed in Euastacus spinifer that originate in different river systems. They are mostly green with reddish-brown joints and bright spines.[2]
Diet
Detritus forms the staple diet of the species but they may also eat small invertebrates and tadpoles.[2] They are also cannibalistic. They are also believed to be opportunistic omnivore.[3]
Life cycle
Mating takes place in winter when temperature drops to as low as 15 °C (59 °F), and eggs are laid in early July. Eggs are carried in the female Pleopods and hatch after an incubation period of 110–140 days. Hatch-lings stay with their parents until early summer. Males mature in 5–6 years and grow to 11 centimetres (4 in) on maturity while females take about 8 years and from above 14 centimetres (6 in). There are a class of "precious males" that mature at 4 centimetres (2 in) length. There are slight variation in reproduction cycle between species in different river systems.[4]
Size
Euastacus spinifer may grow up to 24 centimetres (9 in).[2] Largest recorded weight is 1.8 kilograms (4.0 lb).[5]
Distribution
They are endemic to Australia. They may be found from near sea level to as high as 1,200 metres (3,900 ft). They are distributed over a range of 55,000 square kilometres (21,000 sq mi).[1]
Habitat
Creeks and estuaries are their usual habitats. Their habitats are usually shaded by vegetation.[6]
Moulting
Moulting frequency of individuals in the species differ with size smaller individuals moult up to six times a year while larger individuals moult only once. Different sizes moult a different seasons temperature is believed to be the regulating force.[7]
References
- J. Coughran & J. Furse (2010). "Euastacus spinifer". IUCN Red List of Threatened Species. 2010: e.T153707A4534826. doi:10.2305/IUCN.UK.2010-3.RLTS.T153707A4534826.en.
- "Archived copy". Archived from the original on 2016-03-04. Retrieved 2013-07-09.CS1 maint: archived copy as title (link)
- Diet and feeding in the freshwater crayfish, Euastacus spinifer (Decapoda: Parastacidae), from the Sydney region, AustraliaBy: Turvey, P ;Merrick, J R
- Reproductive biology of the freshwater crayfish, Euastacus spinifer (Decapoda: Parastacidae), from the Sydney region, Australia By Turvey Merrick, J R
- Growth with age in the freshwater crayfish, Euastacus spinifer (Decapoda: Parastacidae), from the Sydney region, Australia By: Turvey, P ;Merrick, J R
- Keith A. Crandall. "Euastacus spinifer Heller 1865". Tree of Life Web Project. Retrieved 8 July 2013.
- Moult increments and frequency in the freshwater crayfish, Euastacus spinifer (Decapoda: Parastacidae), from the Sydney region, Australia By: Turvey, P ;Merrick, J R