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Cryptic diversity that corresponds with island origin has been previously reported in the endemic, geographically restricted sooglossid frogs of the Seychelles archipelago. The evolutionary pattern has not been fully explored, and given current amphibian declines and the increased extinction risk faced by island species, we sought to identify evolutionarily significant units (ESUs) to address conservation concerns for these highly threatened anurans. We obtained genetic data for two mitochondrial (mtDNA) and four nuclear (nuDNA) genes from all known populations of sooglossid frog (the islands of Mahé, Praslin, and Silhouette) to perform phylogenetic analyses and construct nuDNA haplotype networks. Bayesian and maximum likelihood analyses of mtDNA support monophyly and molecular differentiation of populations in all species that occur on multiple islands. Haplotype networks using statistical parsimony revealed multiple high-frequency haplotypes shared between islands and taxa, in addition to numerous geographically distinct (island-specific) haplotypes for each species. We consider each island-specific population of sooglossid frog as an ESU and advise conservation managers to do likewise. Furthermore, our results identify each island lineage as a candidate species, evidence for which is supported by Bayesian Poisson Tree Processes analyses of mtDNA, and independent analyses of mtDNA and nuDNA using the multispecies coalescent. Our findings add to the growing understanding of the biogeography and hidden diversity within this globally important region.

Large carnivores are considered an important component of an ecosystem and their role as apex predators makes them crucial for maintenance of ecosystem function and biodiversity. Yet despite their important ecological value, large carnivores are among the world's most threatened species, mostly due to human persecution and loss of their habitat and prey species. The Arabian leopard (Panthera pardus nimr) is the region's last remaining big cat, and was once widely distributed across the Arabian Peninsula but its occupied range has contracted from ~888,300 km2 to 17,400 km2 since the 1970s, and it is listed as Critically Endangered on the IUCN Red List of Threatened Species. Despite its threatened status, scientific information is lacking for many aspects of the Arabian leopard, including its population and evolutionary genetics. The objectives of this study were therefore to improve the knowledge base to help develop better management strategies for the long-term persistence of the Arabian leopard. By generating a comprehensive mitochondrial DNA sequence database that included sequence data from wild Arabian leopard populations across the Arabian Peninsula my study provided evidence that the Arabian leopard is evolutionarily distinct from other leopard subspecies. Assessment of genetic diversity using a suite of microsatellite markers indicate that the Arabian leopard is genetically impoverished in comparison to other leopard subspecies. However, high levels of genetic diversity and unique alleles were discovered in wild and captive Arabian leopards of Yemeni origin, compared to the wild leopards of the Dhofar mountains of Oman, an area considered to be their last stronghold. Using genetic data from wild leopards obtained via non-invasive scat surveys, we detected fine-scale spatial genetic structure within the leopard population of Dhofar which is likely due to recent human development in the region. DNA surveys of the Dhofar population provided robust estimates of density and population size that are comparable with those derived from camera trap estimates, indicating the reliability of genetic sampling for monitoring of the Arabian leopard. Based on these findings a number of conservation management strategies are proposed including genetic rescue via introgression of Yemen genes to restore the genetic diversity of impoverished populations and enhance the overall evolutionary potential of the Arabian leopard. Other suggested measures include strengthening legislation and enforcement in combination with community engagement to ease human-wildlife conflict as well as the protection and safeguarding of critical habitat and habitat corridors to address population fragmentation. Urgent adoption of these recommendations is required, and the novel information generated by this research provides the evidential basis for their effective implementation that will help ensure the long-term persistence of the Arabian leopard.