Euastacus spinifer

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]

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]

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]

Euastacus spinifer may grow up to 24 centimetres (9 in).[2] Largest recorded weight is 1.8 kilograms (4.0 lb).[5]

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]

Creeks and estuaries are their usual habitats. Their habitats are usually shaded by vegetation.[6]

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]

• Sydney Spiny Crayfish video on Youtube