Crossing the Tasman Sea: Inferring the introduction history ofLitoria aureaandLitoria raniformis(Anura: Hylidae) from Australia into New Zealand

Abstract

Abstract The amphibian fauna of New Zealand consists of three native species (Leiopelmaspp.), and threeLitoriaspecies introduced from Australia in the last 140 years. We conducted a molecular phylogeographical study that aimed to identify the Australian origins of two species,Litoria aureaandLitoria raniformis. We used partial sequences of the mitochondrial cytochrome oxidase I (cox1) gene from 59 specimens sampled from across the range of both species to identify the probable source populations for the New Zealand introductions, and to describe the current genetic diversity among New ZealandLitoriapopulations. Our genetic data suggest thatL. aureawas introduced into the North Island of New Zealand from two regions in Australia, once from the northern part of coastal New South Wales and once from the southern part of coastal New South Wales. Our data indicate thatL. raniformisintroductions originated from the Melbourne region of southern Victoria and once established in the South Island of New Zealand, the species subsequently spread throughout both islands. In addition, we found a distinct haplotype inL. raniformisfrom Tasmania that strongly suggests, contrary to earlier reports, that this species was not introduced into New Zealand from Tasmania. Finally, we identified two very distinctive mitochondrial lineages ofL. raniformiswithin the mainland Australia distribution, which may be previously unrecognized species.