An on-going opportunistic tagging program marked almost 600 giant freshwater crayfish, Astacopsis... more An on-going opportunistic tagging program marked almost 600 giant freshwater crayfish, Astacopsis gouldi, between 22-222 mm carapace length from 123 localities on 62 rivers in Tasmania since 1998. Eighty animals were recaptured once, 50 more than once, and the longest period between initial and latest capture was 8 years. These data were analysed to examine differences in size and growth between the sexes, between the disjunct eastern and western ranges of the species, and between catchments on nutrient-poor and nutrient-rich rocks. Male animals were heavier per unit length than females, as were animals from the western part of the range compared to the naturally disjunct eastern range. Males grew slightly faster than females. Animals from a catchment underlain by nutrient-poor quartzite rocks grew more slowly than those in a neighbouring catchment on richer dolerite. Individual growth histories varied considerably and suggest that there may be fast-growing and slow-growing animals ...
Philosophical Transactions of The Royal Society B Biological Sciences
Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine... more Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritisation 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 thirty two percent 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 geographic 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. Converse...
An on-going opportunistic tagging program marked almost 600 giant freshwater crayfish, Astacopsis... more An on-going opportunistic tagging program marked almost 600 giant freshwater crayfish, Astacopsis gouldi, between 22-222 mm carapace length from 123 localities on 62 rivers in Tasmania since 1998. Eighty animals were recaptured once, 50 more than once, and the longest period between initial and latest capture was 8 years. These data were analysed to examine differences in size and growth between the sexes, between the disjunct eastern and western ranges of the species, and between catchments on nutrient-poor and nutrient-rich rocks. Male animals were heavier per unit length than females, as were animals from the western part of the range compared to the naturally disjunct eastern range. Males grew slightly faster than females. Animals from a catchment underlain by nutrient-poor quartzite rocks grew more slowly than those in a neighbouring catchment on richer dolerite. Individual growth histories varied considerably and suggest that there may be fast-growing and slow-growing animals ...
Philosophical Transactions of The Royal Society B Biological Sciences
Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine... more Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritisation 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 thirty two percent 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 geographic 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. Converse...
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