A new species of Tasmanian mountain shrimp, Anaspides driesseni sp. nov. (Malacostraca, Anaspidacea, Anaspidesidae)

Species of the genus Anaspides, known as mountain shrimps, are endemic to Tasmania and inhabit a variety of freshwater habitats such as mountain tarns, pools, creeks and runnels, as well as caves. Until 2015 only two species of Tasmanian mountain shrimps were recognized, A. tasmaniae (Thomson, 1893), which was believed to be widespread all over the island and A. spinulae from Lake St. Clair. Revision of the genus by Ahyong in 2016 recognized 7 species, most having narrow geographic distributions. Only two widespread species remained: A. richardsoni, occurring mainly on the Central Plateau and its margins, and A. swaini, occurring largely in south-western Tasmania. Notably, within A. swaini, three geographically correlated morphological forms were observed. We re-evaluated all three forms of A. swaini and herein describe one of the forms as a new species, A. driesseni, on the basis of morphological and molecular data. Anaspides driesseni corresponds to A. swaini form 3 and occurs mainly in south-eastern Tasmania from the Hartz Mountains over the Snowy Mountains to the Wellington Range. Telson structure, spination and male secondary sexual characters proved taxonomically instrumental.