FrogEyes
Active member
I found this interesting recent information, which appears to be a presentation on genetic sequencing primers, for a conference:
http://www.dnabarcodes2011.org/documents/presentations/12-2/taxsessionsa/vertebrates/945-Zhou.pdf
Essentially, the authors have come up with what they hope are 'universal' genetic sequences which can be used when sequencing and comparing amphibians. To test the usefulness of those primers, they used them to compare Chinese amphibians - all major taxa of frogs, caecilians, and salamanders among themselves and relative to each other. They focused specifically on Chinese Salamandridae to look at the results, compare to what was already known, and thereby judge the usefulness of the technique.
For the most part, all named groups were identified and confirmed in both distinctiveness and relationships to one another. These effectively validates the technique because it shows that it produces results which agree with other proven methods.
Among Pachytriton, it confirmed all named species, as well as identifying two additional groups which were known and suspected [with weaker support] of being distinct species.
Among Paramesotriton, all named species were confirmed, but very little divergence was found between P.longliensis and P.zhijinensis. Both P.caudopunctatus and P.fuzhongensis were found to consist of what are likely sibling species pairs. An additional undescribed species, related to P.hongkongensis, was identified from between the ranges of P.chinensis and P.hongkongensis.
In Tylototriton, all named Chinese species were confirmed as distinct. However, two separate species were identified as T.verrucosus, and five as T.asperrimus or T.cf.vietnamensis, for a total of eight unnamed species! This actually appears to agree with another recent study which treated similar results for subgenus Yaotriton [in China] as two named and one unnamed species. The key difference is that this study divides Yaotriton into many species because the differences are equal to those found between accepted species of subgenus Tylototriton.
Limitations: Tylototriton vietnamensis and T.notialis are mapped but do not appear to have been included in the study. Thai Tylototriton were also not included. Paramesotriton deloustali was included, but not unidentified Vietnamese species; nor the recently identified form related to P.zhijinensis, from China. Laotriton, Cynops, and Hypselotriton [for the most part] were not included.
Quirks: The unidentified species of warty newt is partly labeled as Pingia granulosa, a name which is currently associated with Pachytriton granulosus through studies of Pachytriton feii. Conversely, no Pingia are identified in the Pachytriton portion of the study. Hypselotriton cyanurus [as Cynops] is identifed as closer to Allomesotriton and Pachytriton than Paramesotriton is, suggesting that Allomesotriton may deserve genus status. Since Japanese Cynops aren't included, no conclusion regarding separation of Hypselotriton can be made. In the Paramesotriton study, P.ermizhaoi is included [now Paramesotriton labiatus], while in the Pachytriton study, Pachytriton labiatus is renamed P.inexpectatus [one correction applied, the other not]. P.guanxiensis is mispelled [it usually is - the original description was "guanxiensis", not "guangxiensis"]. Outgroups are not identified for each genus, which makes it impossible to be sure each genus is truly monophyletic [a single genus]. Fire-bellied toads [Bombinatoridae] were identified as closer to salamanders than to other frogs [I have not seen such a result before] - if confirmed, which seems unlikely, this would require recognition of bombinatorids as a unique and separate group of amphibians.
This presentation is only a cursory overview of the results, and it does not detail methods, materials, statistics, etc. It will be most interesting to see any actual published papers which result from this study, and comparisons with morphological, ecological, and alternate genetic data. It seems likely that the T.hainanensis will be re-confirmed and many new species named, although T.notialis may remain a synonym of typical T.asperrimus. Likewise, at least two Pachytriton and four or more Paramesotriton are likely to be forthcoming. What will come of Cynops, Hypselotriton, or generic status of Allomesotriton may remain enigmatic for a while.
http://www.dnabarcodes2011.org/documents/presentations/12-2/taxsessionsa/vertebrates/945-Zhou.pdf
Essentially, the authors have come up with what they hope are 'universal' genetic sequences which can be used when sequencing and comparing amphibians. To test the usefulness of those primers, they used them to compare Chinese amphibians - all major taxa of frogs, caecilians, and salamanders among themselves and relative to each other. They focused specifically on Chinese Salamandridae to look at the results, compare to what was already known, and thereby judge the usefulness of the technique.
For the most part, all named groups were identified and confirmed in both distinctiveness and relationships to one another. These effectively validates the technique because it shows that it produces results which agree with other proven methods.
Among Pachytriton, it confirmed all named species, as well as identifying two additional groups which were known and suspected [with weaker support] of being distinct species.
Among Paramesotriton, all named species were confirmed, but very little divergence was found between P.longliensis and P.zhijinensis. Both P.caudopunctatus and P.fuzhongensis were found to consist of what are likely sibling species pairs. An additional undescribed species, related to P.hongkongensis, was identified from between the ranges of P.chinensis and P.hongkongensis.
In Tylototriton, all named Chinese species were confirmed as distinct. However, two separate species were identified as T.verrucosus, and five as T.asperrimus or T.cf.vietnamensis, for a total of eight unnamed species! This actually appears to agree with another recent study which treated similar results for subgenus Yaotriton [in China] as two named and one unnamed species. The key difference is that this study divides Yaotriton into many species because the differences are equal to those found between accepted species of subgenus Tylototriton.
Limitations: Tylototriton vietnamensis and T.notialis are mapped but do not appear to have been included in the study. Thai Tylototriton were also not included. Paramesotriton deloustali was included, but not unidentified Vietnamese species; nor the recently identified form related to P.zhijinensis, from China. Laotriton, Cynops, and Hypselotriton [for the most part] were not included.
Quirks: The unidentified species of warty newt is partly labeled as Pingia granulosa, a name which is currently associated with Pachytriton granulosus through studies of Pachytriton feii. Conversely, no Pingia are identified in the Pachytriton portion of the study. Hypselotriton cyanurus [as Cynops] is identifed as closer to Allomesotriton and Pachytriton than Paramesotriton is, suggesting that Allomesotriton may deserve genus status. Since Japanese Cynops aren't included, no conclusion regarding separation of Hypselotriton can be made. In the Paramesotriton study, P.ermizhaoi is included [now Paramesotriton labiatus], while in the Pachytriton study, Pachytriton labiatus is renamed P.inexpectatus [one correction applied, the other not]. P.guanxiensis is mispelled [it usually is - the original description was "guanxiensis", not "guangxiensis"]. Outgroups are not identified for each genus, which makes it impossible to be sure each genus is truly monophyletic [a single genus]. Fire-bellied toads [Bombinatoridae] were identified as closer to salamanders than to other frogs [I have not seen such a result before] - if confirmed, which seems unlikely, this would require recognition of bombinatorids as a unique and separate group of amphibians.
This presentation is only a cursory overview of the results, and it does not detail methods, materials, statistics, etc. It will be most interesting to see any actual published papers which result from this study, and comparisons with morphological, ecological, and alternate genetic data. It seems likely that the T.hainanensis will be re-confirmed and many new species named, although T.notialis may remain a synonym of typical T.asperrimus. Likewise, at least two Pachytriton and four or more Paramesotriton are likely to be forthcoming. What will come of Cynops, Hypselotriton, or generic status of Allomesotriton may remain enigmatic for a while.