Geoemydidae

Abstract: The turtle family Geoemydidae represents the largest, most diverse, and most poorly understood family of turtles. Little is known about this group, including intrafamilial systematics. The only complete phylogenetic hypothesis for this family positions geoemydids as paraphyletic with respect to tortoises, but this arrangement has not been accepted by many workers. We compiled a 79-taxon mitochondrial and nuclear DNA data set to reconstruct phylogenetic relationships for 65 species and subspecies representing all 23 genera of the Geoemydidae. Maximum parsimony (MP) and maximum-likelihood (ML) analyses and Bayesian analysis produced similar, well-resolved trees. Our analyses identified three main clades comprising the tortoises (Testudinidae), the old-world Geoemydidae, and the South American geoemydid genus Rhinoclemmys. Within Geoemydidae, many nodes were strongly supported, particularly based on Bayesian posterior probabilities of the combined three-gene dataset. We found that adding data for a subset of taxa improved resolution of some deeper nodes in the tree. Several strongly supported groupings within the Geoemydidae demonstrate non-monophyly of some genera and possible interspecific hybrids, and we recommend several taxonomic revisions based on available evidence.

Abstract: Asian box turtles (genus Cuora, family Geoemydidae) comprise a clade of 12 aquatic and semiaquatic nominate species distributed across southern China and Southeast Asia. Over the last two decades, turtles throughout Asia have been harvested at an unsustainable rate to satisfy demands for food, traditional Chinese medicine, and the pet trade. Con- sequently, all species of Cuora were recently placed on the IUCN Red List, nine are currently listed as criti- cally endangered by the IUCN, and all species are listed in Appendix II of CITES. We compiled a 67-specimen mitochondrial (~1,650 base pairs (bp) from two mitochondrial genes) and a 40-specimen nuclear-plus-mitochondrial (~3,900 bp total, three nuclear introns plus an additional ~860 bp mitochon- drial gene fragment) DNA data set to reconstruct the phylogeny of Cuora species and to assess genetic diversity and species boundaries for several of the most problematic taxa. Our sampling included 23 C. trifas- ciata ,1 7C. zhoui and 1-4 individuals of the remaining 10 species of Cuora. Maximum likelihood, maximum parsimony and Bayesian analyses all recovered similar, well resolved trees. Within the Cuora clade, mito- chondrial and nuclear sequence data indicated that both C. zhoui and C. mccordi represent old lineages with little or no history of interspecific gene flow, suggesting that they are good genealogical species. Based on mtDNA, Cuora pani was paraphyletic and C. trifasciata was composed of two highly divergent lineages that were not each other's closest relatives; both cases of non-monophyly were due to a mtDNA sequence that was widespread and identical in C. aurocapitata, C. pani and C. trifasciata. However, when combined with nuclear DNA results, our data indicate that C. trifasciata is a single, monophyletic taxon, and that mitochondrial introgression and nuclear-mitochondrial pseudogenes have led to a complex pattern of mitochondrial gene relationships that does not reflect species-level histories. Our results imply that captive ''assurance colonies'' of both C. trifasciata and C. pani should be genotyped to identify pure, non-hybrid members of both taxa, and we recommend that introgressed and pure taxa be man- aged as independent entities until the full evolutionary histories of these critically endangered turtles are resolved.

Abstract: Barth, D. Bernhard, D. Fritzsch, G. & Fritz, U. (2004): The freshwater turtle genus Mauremys— a textbook example of an east–west disjunction or a taxonomic misconcept? —Zoologica Scripta, 33, 213–221. We compare 1036 bp of the mitochondrial cytochrome b gene (cyt b) from all six Mauremys species with 16 other taxa, representing both currently recognized subfamilies of the Geoemydidae (Geoemydinae and Batagurinae) to contribute a comprehensive dataset towards resolving the conflicting Mauremys taxonomy and phylogeography. Mauremys, a representative of the Geoemydinae, is thought to be an example of a taxon with an east–west disjunction due to Pleistocene glacial extinction, with species occurring in the western Palearctic and species in the eastern Palearctic and Oriental regions. Our results contradict this traditional zoogeographical scheme and the current taxonomy of the Geoemydidae. Mauremys is paraphyletic with respect to two East Asian genera belonging to the Batagurinae: Chinemys and Ocadia. Therefore, Mauremys, as currently understood, clearly represents a taxonomic misconcept. Mauremys+Chinemys+Ocadia contains four well supported clades, two of which —M. japonica+Chinemys+Ocadia and M. annamensis+M. mutica— are confined to eastern Asia. The other two —M. caspica+M. rivulata and M. leprosa— occur in the western Palearctic. Mauremys leprosa may represent an ancient lineage which differentiated before the split between the other western and eastern species occurred. The patchy distribution of the four clades is likely the result of several ancient radiations rather than of a Pleistocene extinction. The sister-group of Mauremys+Chinemys+Ocadia is Cuora, a morphologically highly specialized genus with a complicated shell hinging mechanism.

Abstract: Using DNA sequences of the mitochondrial cytochrome b gene, we investigated phylogeny and taxonomy of South and South-east Asian turtles of all species and subspecies of the genera Batagur, Callagur, Hardella, Kachuga and Pangshura. We found three major clades: (i) a moderately to well-supported clade containing all large riverine species assigned so far to Batagur, Callagur and Kachuga; (ii) a well-supported monophylum comprising the four Pangshura species; and (iii) Hardella that could constitute either the sister-taxon of Pangshura or of a clade comprising Batagur, Callagur, Kachuga and Pangshura. The genus Kachuga is clearly polyphyletic. Therefore, we recommend placing all Batagur, Callagur and Kachuga species in one genus. According to the International Code of Zoological Nomenclature Batagur Gray, 1856, being originally erected at higher rank, takes precedence over the simultaneously published name Kachuga Gray, 1856, and the younger name Callagur Gray, 1870, resulting in an expanded genus Batagur. Indonesian and Malaysian Batagur baska proved to be highly distinct from our sequences of this species from the Sundarbans (Bangladesh, adjacent India), suggesting that a previously unidentified species is involved. This finding is of high conservation relevance in the critically endangered B. baska. The currently recognized subspecies within Hardella thurjii, Pangshura smithii and P. tentoria do not correspond well with mtDNA clades. Considering that the two subspecies of H. thurjii are likely to be based only on individual ontogenetic differences, we propose abandoning the usage of subspecies within H. thurjii. In the Ghaghra River, Uttar Pradesh (India) we detected shared haplotypes in P. smithii and P. tentoria, implying that the unusual morphological characters of the Ghaghra River population of P. tentoria could be the result of interspecific hybridization.