| || || Osborne-Naikatini, Tamara|
| || || Phylogeography, species distribution modelling, mitochondrial genome evolution and conservation of the Fijian frogs (Ceratobatrachidae) |
Institution: University of the South Pacific.
Subject: Frogs -- Fiji -- Geographical distribution, Frogs -- Conservation -- Fiji
Call No.: Pac QL 668 .E27 O67 2015
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: The Fijian Cornufer (Subgenus Cornufer) species are the easternmost extent of a native amphibian species in the South Pacific, and are endemic to the Fijian archipelago. Both species are currently classified by the International Union for the Conservation of Nature (IUCN) as threatened. There is distinct genetic divergence between certain island populations, which would suggest that insular isolation has led to evolution of multiple, additional species. These characteristics along with traits that identify other Ceratobatrachid frogs (polymorphic colouration, terrestrial breeding, unique characteristics of larval development, calling patterns), make for a particularly interesting branch of the anuran tree of life. In this thesis I review the conservation status of the Fijian frogs synthesising geo-spatial and genetic analyses. The geo-spatial analyses indicate a need to re-assess the conservation status of the Fijian tree frog (Cornufer vitiensis), and for a systematic reappraisal of the Fijian ground frog (Cornufer vitianus). Novel characterisations of genome structure were generated. The complete mitochondrial genomes for both Fijian Ceratobatrachids were sequenced, showing a unique gene order for Neobatrachian frogs. This provides empirical data which may further current understanding of molecular evolution in neobatachrian lineages. The mitochondrial and nuclear data enable the identification of Integrated Operational Taxonomic Units (IOTUs) amongst island populations of both species. All of the genetic markers indicated that the Taveuni Island populations are divergent, possibly sub-species. Populations of Cornufer on Vanua Levu Island are likely source populations for the other islands in the Fiji group, and could well be the founding population of a putative Cornufer colonizing ancestor. Conservation efforts directed towards the Taveuni and Vanua Levu Island populations of Cornufer would inevitably safeguard two levels of genetic distinctiveness: ancestral genotypes with a possible evolutionary history of hybridization (and the capacity for generating transgressive phenotypes), as well as a divergent population of C. vitianus.