27 research outputs found
A revision of the Tasmanian freshwater crayfish genus Astacopsis Huxley (Decapoda: Parastacidae)
During a broad study of the biology of the freshwater crayfishes in the Tasmanian genus Astacopsis, two distinct forms of Astacopsis franklinii were recognised. These "forms" were found to differ in terms of their general morphology and distribution. As a result, the taxonomy of Astacopsis has been revised to re-establish the three species originally described by Ellen Clark. Astacopsis franklinii Gray has been divided into two separate species, the eastern Astacopsis franklinti and the western Astacopsis tricornis, while the status of Artacopsis gouldi remains unaltered
An assessment of the Caroline Creek freshwater crayfish reserve in northern Tasmania
A preliminary investigation of the Caroline Creek freshwater crayfish reserve was conducted over a threeday period in 1987. Data are presented to show that the population numbers of Aslacopsis gouldi, for which the reserve was gazetted, are low and that large and mature animals were not found. The presence of numerous bait lines throughout the reserve shows that illegal fishing has occurred and is continuing, and suggests that management practices reserve have been inappropriate. The need for effective reserves for A. gouldi is discussed
Wild Turkey, Meleagris gallopavo silvestris, Behavior in Central Ontario During Winter
Home range size, food habits, and roost site selection are described for the Eastern Wild Turkey (Meleagris gallopavo silvestris) introduced on the Precambrian Shield in central Ontario during the winters 1999 and 2000. Monthly home range size was correlated primarily to snow depth, although it was also likely associated to other factors, including food availability and/or roost site availability. Ferns and allies were used more than available, whereas monocots were used less than expected. Roost site-selection was primarily influenced by tree height. If the Eastern Wild Turkey is to expand its northern range in Ontario, winter food and roost site availability may be the primary determinants for successful introductions
Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea)
International audienceRates 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