RESUMO
The Striped Legless Lizard Delma impar Fischer 1882 occurs in grasslands of south-eastern Australia where it is sometimes sympatric with several congeners. Previous molecular analyses have revealed mitochondrial divergence between the northern and southern lineages of D. impar, but the status of a recently detected population assigned to the species in the Hunter Valley of New South Wales (NSW), 250 km north of other populations, remains unknown. Via morphological and molecular analyses across the known distribution of D. impar, we distinguish the population from the Hunter Valley, Liverpool Plains region as a unique taxon and describe this species as D. vescolineata sp. nov. The new species is divergent from D. impar in both nuclear and mitochondrial analysis, and differing facial scalation and colour patterning from the limited number of specimens available. The degree of mitochondrial and nuclear divergence between the previously identified northern and southern clades of D. impar is consistent with a single species. This is the first description of a Delma from south-eastern Australia since 1974, but the second new vertebrate taxon identified from the Hunter Valley region within a decade. Our research highlights our incomplete understanding of the biodiversity of the Hunter Valley region, despite its relative proximity to populous areas. The range of D. vescolineata sp. nov. is restricted and heavily overlaps with major habitat modification including mining and grazing, with no parks or reserves in this distribution protecting the species grassland habitat. Gathering more data to understand conservation status of this species should be a priority.
Assuntos
Lagartos , Animais , Biodiversidade , Ecossistema , New South Wales , FilogeniaRESUMO
The six species of mountain frogs (Philoria: Limnodynastidae: Anura) are endemic to south-eastern Australia. Five species occur in headwater systems in mountainous north-eastern New South Wales (NSW) and south-eastern Queensland (Qld), centred on the Gondwana Rainforests of Australia World Heritage Area. A previous molecular genetic analysis identified divergent genetic lineages in the central and western McPherson Ranges region of Qld and NSW, but sampling was inadequate to test the species status of these lineages. With more comprehensive geographic sampling and examination of the nuclear genome using SNP analysis, we show that an undescribed species, P. knowlesi sp. nov., occurs in the central and western McPherson Ranges (Levers Plateau and Mount Barney complex). The new species is not phylogenetically closely related to P. loveridgei in the nuclear data but is related to one of two divergent lineages within P. loveridgei in the mtDNA data. We postulate that the discordance between the nuclear and mtDNA outcomes is due to ancient introgression of the mtDNA genome from P. loveridgei into the new species. Male advertisement calls and multivariate morphological analyses do not reliably distinguish P. knowlesi sp. nov. from any of the Philoria species in northeast NSW and southeast Qld. The genetic comparisons also enable us to define further the distributions of P. loveridgei and P. kundagungan. Samples from the Lamington Plateau, Springbrook Plateau, Wollumbin (Mt Warning National Park), and the Nightcap Range, are all P. loveridgei, and its distribution is now defined as the eastern McPherson Ranges and Tweed caldera. Philoria kundagungan is distributed from the Mistake Mountains in south-eastern Qld to the Tooloom Scrub on the Koreelah Range, southwest of Woodenbong, in NSW, with two subpopulations identified by SNP analysis. We therefore assessed the IUCN threat category of P. loveridgei and P. kundagungan and undertook new assessments for each of its two subpopulations and for the new taxon P. knowlesi sp. nov., using IUCN Red List criteria. Philoria loveridgei, P. kundagungan (entire range and northern subpopulation separately) and P. knowlesi sp. nov. each meet criteria for Endangered (EN B2(a)(b)[i, iii]). The southern subpopulation of P. kundagungan, in the Koreelah Range, meets criteria for Critically Endangered (CE B2(a)(b)[i, iii]). These taxa are all highly threatened due to the small number of known locations, the restricted nature of their breeding habitat, and direct and indirect threats from climate change, and the potential impact of the amphibian disease chytridiomycosis. Feral pigs are an emerging threat, with significant impacts now observed in Philoria breeding habitat in the Mistake Mountains.
Assuntos
Anuros , Floresta Úmida , Animais , Anuros/genética , Austrália , DNA Mitocondrial/genética , Masculino , FilogeniaRESUMO
The hip-pocket frog (Assa darlingtoni), a small terrestrial myobatrachid frog found in mid-eastern Australia, has a highly derived, unusual, reproductive mode involving a unique form of male parental care. Males have subcutaneous pouches that open near the hip, and the developing tadpoles are carried in these pouches to post metamorphosis. It is found on several isolated mountain ranges in closed forest habitats, associated with high rainfall and temperate or sub-tropical climates. We established genetic relationships among specimens sampled across the range using phylogenetic analyses of thousands of single nucleotide polymorphisms (SNPs) from the nuclear genome and mitochondrial ND2 gene nucleotide sequences. These analyses uncovered two lineages that are genetically distinct in both nDNA and mtDNA analyses and that have low levels of divergence in male advertisement calls and are morphologically cryptic. Our data support separate species status for each lineage, based on the molecular genetic data. The first, which we name as a new species, Assa wollumbin sp. nov., is restricted to a single mountain, Wollumbin (= Mount Warning), the eroded cone of an ancient shield volcanothe Tweed Volcano. The second, the nominal species A. darlingtoni, has a wider distribution in five geographically disjunct subpopulations along 430 km of the Great Dividing Range in south-eastern Queensland and north-eastern New South Wales. The distributions of the two species closely approach within 15 km of each other on the central plug and rim of the caldera of the Tweed Volcano. Assa wollumbin sp. nov. meets the conservation criteria for Critically Endangered [A3(e), B2(a,b)]. When all subpopulations of A. darlingtoni are combined the conservation assessment is Endangered [A3(e), B2(a,b)]. Because of the fragmented nature of the distribution of A. darlingtoni, combined with the genetic evidence of concordant sub-structuring, we also conducted a conservation assessment on the five subpopulations. Two were assessed as Critically Endangered (DAguilar Range and Conondale/Blackall Ranges), and the remainder as Endangered (Dorrigo Plateau, McPherson Ranges, and Gibraltar Ranges/Washpool).
Assuntos
Anuros , DNA Mitocondrial , Animais , Anuros/genética , Austrália , DNA Mitocondrial/genética , Ecossistema , Masculino , FilogeniaRESUMO
Population declines and range contractions among Australian frogs that commenced in the early 1980s continue in some species that were once widespread. The generality of this pattern has been difficult to discern, especially for those species that are encountered rarely because they have restricted periods of calling activity with poorly defined habitat preferences, and are not common. Several lines of evidence indicate that Litoria littlejohni is such a species. This frog was once known from mid-eastern New South Wales to eastern Victoria, and evidence from wildlife atlas databases and targeted searches indicate that it has declined in large portions of its former range, leaving several populations that are isolated, in some cases restricted in distribution, and of small size. We investigated the relationships among populations using mitochondrial ND4 nucleotide sequences and single nucleotide polymorphisms (SNPs) from the nuclear genome. We found that northern and southern populations form two highly divergent genetic groups whose distributions abut at the southern margin of the Sydney Basin Bioregion and these genetic groups also show divergence in morphology and male advertisement calls. Here we describe the populations to the south of the Sydney Basin Bioregion as a new species and provide information on its distribution and ecology. In light of the apparent isolation and small size of known populations of the new species and the consequent restriction of the range of L. littlejohni, we assessed the conservation status of both species.