Academic literature on the topic 'Tasmanian mountain shrimp'

The iconic ‘mountain shrimps’ of the genus Anaspides Thomson, 1894, are endemic to Tasmania, inhabiting various freshwater habitats such as mountain tarns and creeks, as well as streams inside caves. They are often labelled as ‘living fossils’ because of their close resemblance to their Triassic relatives. Prior to 2015, only two species were recognised but recent studies have uncovered a total of at least seven species. The type species of Anaspides, A. tasmaniae (Thomson, 1893), was previously believed to occur throughout Tasmania, but following a review in 2016, this species was confirmed only from a small range on the east and south-east side of Mt Wellington, with Anaspides from other parts of Tasmania referable to other species. We herein provide a detailed assessment of the distribution and genetic structure of A. tasmaniae based on extensive field surveys throughout the ranges of all species of Anaspides. The distribution of A. tasmaniae is extended to include four separate localities in and around the Mt Field National Park, 50 km north-west of Mt Wellington. The recovered genetic structure of A. tasmaniae based on 48 specimens indicates that the disjunct distribution is unlikely to be the result of artificial translocation but, instead, probably reflects postglacial relictualisation of a formerly continuous range present during Pleistocene glacial maxima. Of particular interest is the record of syntopy in Anaspides, observed at the entrance of Khazad Dum cave, where both A. tasmaniae and A. swaini inhabit the inflow stream.

The endemic Tasmanian mountain shrimps of the genus Anaspides Thomson, 1894 (Anaspidacea) have attracted considerable scientific interest as potential basal eumalacostracans and as 'living fossils', closely resembling their Triassic forbears (Coineau & Camacho 2013). Two species are currently recognised, with A. tasmaniae (Thomson, 1893) (type locality: Mount Wellington) accorded a wide range throughout most of central, western and southern Tasmania, and A. spinulae Williams, 1965, believed restricted to central Tasmania from Lake St. Clair (type locality) and immediate environs (O’Brien 1990). Despite the current taxonomy, heterogeneity in A. tasmaniae has been increasingly suggested, which may have important conservation management implications (e.g., Jarman & Elliot 2000). Jarman & Elliott (2000) recognised three potential clades (based on mitochondrial 16S sequences) that may correspond to separate species. A taxonomic and phylogenetic revision of the genus, now in progress, found A. tasmaniae to be restricted to the vicinity of Mount Wellington, and all Anaspides from other localities to represent other species. Owing to delays in the completion of the revision, however, some of the new species of Anaspides are briefly diagnosed below in order to make the formal species names available for other studies now underway. Full accounts of the species of Anaspides will be given when the revision of the genus is completed.