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Measey G.J.,North West University South Africa | Rodder D.,Section of Herpetology | Green S.L.,Stanford University | Kobayashi R.,Niigata University | And 4 more authors.
Biological Invasions | Year: 2012

We conducted a literature review on the current status of all known extralimital populations of the African clawed frog, Xenopus laevis, to identify commonality in invasion pathways, lag between discovery and introduction, and whether old populations are in decline. Further, we investigated which locations are vulnerable to future establishment using geospatial data (1,075 native and 124 invasive records) in a Maxent model developed with data from the Worldclim database. We found introductions of X. laevis to be continuous over the last 50 years and invasions to be ongoing on four continents: Asia, Europe, North and South America. Invasion pathways were related to scientific use and the pet trade, with high rates of deliberate release followed by a lag of 2-25 years to first reports. No populations were found to be declining although some have been extirpated. Optimal uninvaded bioclimatic space was identified in central Mexico and southern Australia, while larger suitable areas were found in southern South America and southwestern Europe. Xenopus laevis is a cryptic invasive species that is likely to increase its invasive distribution, through new introductions and by the spread of ongoing invasions. Many more invasive populations are likely to exist than are currently recognised and reducing invasive potential will largely rely on education of those involved with their captive care. © 2012 Springer Science+Business Media B.V. Source


Spinks P.Q.,University of California at Los Angeles | Thomson R.C.,University of Hawaii at Manoa | Pauly G.B.,Section of Herpetology | Newman C.E.,Louisiana State University | And 2 more authors.
Molecular Phylogenetics and Evolution | Year: 2013

Reconstructing species trees for clades containing weakly delimited or incorrectly identified taxa is one of the most serious challenges facing systematists because building phylogenetic trees is generally predicated on correctly identifying species membership for the terminals in an analysis. A common practice, particularly in large-scale phylogenetic analyses, is to use single-exemplar sampling under the implicit assumption that the resulting phylogenetic trees will be poorly supported if the sampled taxa are not good species. We examine this fundamental assumption in the North American turtle genus Pseudemys, a group of common, widely distributed freshwater turtles whose species boundaries and phylogenetic relationships have challenged systematists for over half a century. We sequenced 10 nuclear and three mitochondrial genes from the nine currently recognized species and subspecies of Pseudemys using geographically-widespread sampling of each taxon, and analyzed the resulting 86-individual data set using population-genetic and phylogenetic methods. We found little or no evidence supporting the division of Pseudemys into its currently recognized species/subspecies. Rather, our data strongly suggest that the group has been oversplit and contains fewer species than currently recognized. Even so, when we conducted 100 replicated, single-exemplar phylogenetic analyses of these same nine taxa, most Bayesian trees were well resolved, had high posterior probabilities, and yet returned completely conflicting topologies. These analyses suggest that phylogenetic analyses based on single-exemplar sampling may recover trees that depend on the individuals that are sampled, rather than the underlying species tree that systematists assume they are estimating. Our results clearly indicate that final resolution of Pseudemys will require an integrated analysis of morphology and historical biogeographic data coupled with extensive geographic sampling and large amounts of molecular data, and we do not recommend taxonomic changes based on our analyses. If our 100-tree resampling experiments generalize to other taxa, they suggest that single-exemplar phylogenies should be interpreted with caution, particularly for groups where species are shallowly diverged or inadequately delimited. © 2013 Elsevier Inc. Source


Pauly G.B.,Section of Herpetology
Southwestern Naturalist | Year: 2012

Freeze tolerance is the ability of an organism to survive from water in portions of its body freezing due to molecular, biochemical, physiological, or a combination of these adaptations. Within squamates, freeze tolerance is documented or suspected, based on observations of freezing survival in only five species. I report an observation of survival of short-term freezing in the eastern fence lizard, Sceloporus undulatus. Source


Malonza P.K.,Section of Herpetology | Granthon C.,Texas Christian University | Williams D.A.,Texas Christian University
Zootaxa | Year: 2016

A new species of Lygodactylus gecko (L. wojnowskii sp. nov.) is described from the vicinity of Chogoria Town on the eastern lower slopes of Mt. Kenya in central Kenya. A phylogeny based on mitochondrial and nuclear DNA shows that the proposed new taxon is distinct within the Lygodactylus picturatus group and is the sister lineage to L. mombasicus and L. kimhowelli. It is morphologically very similar to both L. mombasicus and L. keniensis but its dorsal coloration and pat-Tern is different. Its dorsum is grey with dark stripes while its head has black and white stripes that form a Y-shaped mark. While the male throat pattern is similar to that of L. mombasicus, that of the female is like that of females and some males of Lygodactylus keniensis. Lygodactylus wojnowskii sp. nov. has a higher number of post-postmental scales (6) than do its close relatives (5). The new species is distributed on the lower slopes of mid-Altitude areas on eastern Mt. Kenya, but it may occur in other areas at similar elevations in central Kenya. It is associated with short, scattered trees within agricul-Tural areas. It has not yet been recorded within the protected Chogoria forest block of Mt. Kenya forest. It is likely present in Mwea National Reserve as it occurs in nearby areas. Copyright © 2016 Magnolia Press. Source


John Measey G.,Nelson Mandela Metropolitan University | Muchai V.,Section of Herpetology | Spawls S.,7 Crostwick Lane
African Zoology | Year: 2012

The dearth of information on caecilian amphibians is most likely due to a lack of directed field studies. Here we report the rediscovery of a population of Boulengerula denhardti nearly a century after its description by Nieden in 1912. Morphological examination of seven specimens suggests that they are closer to the type of B. denhardti than to any other member of the genus. Nieden's type locality has been widely interpreted as the Tana River Delta, although searches there have not revealed specimens of this species. The locality of the material described herein comes from Ngaia Forest, Meru County, Kenya, approximately 420 km, northwest of the Tana Delta. We discuss dispersal in caecilians and their likely use of riverine corridors. We speculate that more species in this genus are likely to be found in Kenya. Source

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