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The biology of Euastacus mirangudjin, a small freshwater crayfish from subtropical eastern Australia, is described for the first time. Long-term monitoring was undertaken at a site in Toonumbar National Park to gather data on growth, moulting, maturity and reproductive activity To complement field observations, egg and juvenile development was further studied in laboratory aquaria. The orange- bellied crayfish reaches less than 40 mm carapace length, with female maturity occurring near 30 mm. Animals do not respond to baits, and appear to spend most of their time within their burrows. The species is an Autumn-Spring brooder with a distinctly low fecundity and large, ovoid eggs (3.0 x 3.8 mm), and females do not appear to routinely moult prior to spawning. At some sites, the species co-occurs with the much larger and spinier E su!catus. A high incidence of regenerate chelipeds, missing limbs and other wounds was recorded. Euastacus mirangudjin hosts a small, unpigmented Temnocephalan flatworm.The biology and ecology of the species is discussed with reference to other species in the genus Euastacus. [ABSTRACT FROM AUTHOR]

The biology of Euastacus gumar, a poorly known species of crayfish from northeastern New South Wales, is recorded for the first time.The distribution of the species was compiled following a major regional survey, and micro- and macro-habitat information was recorded at each site. Long-term monitoring was carried out at one site in Culmaran Creek to gather data on growth, moulting, maturity and reproductive activity, and berried females were retained in aquaria to study egg and juvenile development. The species is slow-growing and likely long-lived. Moulting occurs during the warmer months, and growth increments are small (0.8-2.3 mm OCL).A small proportion (< 50%) of mature females breed during the cooler months, carrying 20-ISO eggs for a relatively short gestation period (2 months). Although the species does not rely on flowing or standing water, it is restricted to the rainforested headwater reaches of each of the nine streams it inhabits, and large areas of cleared, agricultural land separate the species into three disjunct areas on the Richmond Range and theYabbra Spur. Euastacus gumar is a narrow range taxon with a fragmented, highland distribution (overall extent of occurrence = 985 km2).The species is uncommon across its range, and under IUCN criteria should be considered `Endangered' due to its restricted and fragmented distribution and an anticipated decline in the quality and amount of habitat due to climate change. [ABSTRACT FROM AUTHOR]

The Yabby Cherax destructor has a natural distribution across inland river systems in central and south-eastern Australia. Within that range it supports important recreational and commercial fisheries, and is also widely used for aquaculture and as a pet in the aquarium trade. Recently, the species has become established in parts of Australia outside its natural range. This paper documents sites of translocation in the coastal drainages of eastern New South Wales, Australia. Potential implications of these translocations are discussed with regard to the native aquatic fauna of the region. We draw particular attention to: (i) the native species of amphibian that are threatened by predation by introduced yabbies, and (ii) the native crayfish fauna threatened by competition with this species. The Fitzroy Falls Crayfish Euastacus dharawalus has a distribution restricted to one small catchment and C. destructor has been recently translocated into this creek. On the basis of these data, we propose to nominate C. destructor as a key threatening process under the Threatened Species Conservation Act 1995 and Euastacus dharawalus as a threatened species, also under that Act. [ABSTRACT FROM AUTHOR]

This paper examines the distribution, habitat and conservation status of five species of the freshwater crayfish genus Euastacus from eastern Australia: E. dalagarbe, E. girurmulayn, E. guruhgi, E. jagabar and E. mirangudjin. Although the five species have discrete distributions, they have similar habitat requirements, occurring only at highland (310-960 m) sites in the Central Eastern Rainforest Reserves of Australia. They all occur in minor or peripheral habitats (i.e. small tributaries, damp gullies and wet soaks) and are sympatric with the much larger species, E sulcatus. On the basis of their restricted ranges, E. girurmulayn, E. guruhgi, E. jagabar and E. mirangudjin satisfy the IUCN criteria for listing as 'Vulnerable' (VU D2). Euastacus dalagarbe is close to qualifying for listing as vulnerable, and can be considered as 'Near Threatened'. Potential threats for these species are discussed. [ABSTRACT FROM AUTHOR]

Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach.