A new species of Peronia Fleming, 1822 (Gastropoda, Euthyneura, Pulmonata, Onchidiidae) from the Northern Territory, Australia

A new species of Peronia is described from Darwin, Northern Territory, Australia: Peronia watts, new species. Evidence for a new species comes from mitochondrial and nuclear DNA sequences as well as comparative anatomy. Specimens of Peronia watts, new species, cluster together in a reciprocally monophyletic unit separated by a large gap in genetic distances. Peronia watts, new species, is also characterised by unique anatomical traits: it is the only Peronia species known to secrete an abundant, sticky mucus when handled, its radula contains up to 150 teeth per half row (which is unusually high), and the retractor muscle of its copulatory organ does not seem to insert anywhere in the visceral cavity. Peronia watts, new species, is only abundant locally, in its specific habitat (large moist claystone boulders in small rocky coves). It is currently endemic to Darwin Harbour, but its geographic distribution may be shown to be larger in the future. The present description shows the critical importance of taxonomic revisions because discovering this new species would have been impossible without the recent revision of Peronia.