Thursday, May 5, 2016

[Herpetology • 2016] Triturus anatolicus • Description of A New Species of Crested Newt, previously subsumed in Triturus ivanbureschi (Caudata: Salamandridae)

 Anatolian Crested Newt |  Triturus anatolicus 
Wielstra & Arntzen, 2016 


Multilocus molecular data play a pivotal role in diagnosing cryptic species (i.e. genetically distinct but morphologically similar species). A multilocus phylogeographic survey has provided compelling evidence that Triturus ivanbureschi sensu lato comprises two distinct gene pools with restricted gene flow. We conclude that this taxon had better be treated as two distinct (albeit morphologically cryptic) species. The name T. ivanbureschi should be restricted to the western species, which is distributed in western Asiatic Turkey plus the south-eastern Balkan Peninsula. No name is as yet available for the eastern species, which is distributed in northern Asiatic Turkey. We propose the name Triturus anatolicus sp. nov. for the eastern species and provide a formal species description.

Keywords: gene flow, introgression, phylogeny, Triturus anatolicus sp. nov., Triturus karelinii, Amphibia

Distribution. The distribution encompasses Asiatic Turkey south of the Black Sea, reaching up to c. 200 kilometers inland (usually less), but not into inner Anatolia. To the west the new species reaches the Bosphorus at the northern side of the Marmara Sea. On the southern side of the Marmara Sea it meets T. ivanbureschi sensu stricto, east of Lake Ulubat and west of the city of Bursa. The two species form a hybrid zone here (Wielstra et al., submitted). To the east the new species reaches the town of Yomra, just east of the city of Trabzon. The nearest known Triturus localities further east are from the extreme NE of Turkey, over 150 km away, and probably concern T. karelinii sensu stricto (Wielstra et al., 2013a). An outline of the distribution of the new species is provided in Fig. 1. A database of distribution records is provided in Wielstra et al. (2014b).

Etymology. The specific epithet reflects the distribution of the new Triturus species. Triturus anatolicus sp. nov. is endemic to Anatolia. It is the only Triturus species to which this applies. It should be noted that the range of T. ivanbureschi sensu stricto covers western Anatolia (Wielstra et al., 2013a; Wielstra et al., submitted) and the range of T. karelinii sensu stricto probably protrudes into northeastern Anatolia (Wielstra et al., 2010).

Proposed vernacular name. We propose to use the vernacular name Anatolian Crested Newt for T. anatolicus sp. nov. This name highlights its status as an Anatolian endemic. We suggest to use the vernacular name Balkan Crested Newt for T. ivanbureschi sensu stricto (rather than Balkan-Anatolian Crested Newt previously applied to T. ivanbureschi sensu lato). Although T. ivanbureschi sensu stricto also partially occurs in Anatolia, the main part of its range is in the Balkan Peninsula.

We have taken a cautious approach in revising the taxonomy of T. karelinii sensu lato. We first split the group into T. karelinii sensu stricto and T. ivanbureschi sensu lato and preferred to await a detailed analysis of the putative hybrid zone between the two candidate species within T. ivanbureschi sensu lato before considering whether further taxonomic change was warranted (Wielstra et al., 2013b). By applying a next-generation sequencing protocol for Triturus (Wielstra et al., 2014a) to a detailed sampling in and around the putative hybrid zone (Wielstra et al., submitted) we could confirm the existence of an as yet undescribed cryptic species in T. ivanbureschi sensu lato. This gave us the confidence to describe T. anatolicus sp. nov. in the present paper. Our studies on Triturus illustrate how ‘shallow genomics’ (Zilversmit et al., 2002), in which a comprehensive but tractable portion of the total genome is employed to approximate evolutionary history, can be a driving force in taxonomy. As yet no diagnostic morphological characters are known to distinguish the three species comprising T. karelinii sensu lato. This raises the question: are the three crested newt species truly cryptic, or have they not been studied closely enough? Considering that previous morphological studies have mainly focused on the species meeting in the Balkan Peninsula rather than T. karelinii sensu lato (Arntzen, 2003) we suspect the latter. A future morphological study, using the genetic results as a guidance, should prove illuminating.

Wielstra, B. and Arntzen, J.W. 2016. Description of A New Species of Crested Newt, previously subsumed in Triturus ivanbureschi (Amphibia: Caudata: Salamandridae). Zootaxa. 4109(1); DOI: 10.11646/zootaxa.4109.1.7

Wielstra, B., S. n. Litvinchuk, B. Naumov, N. Tzankov and J. w. Arntzen. 2013. A Revised Taxonomy of Crested Newts in the Triturus karelinii Group (Amphibia: Caudata: Salamandridae), with the Description of A New Species. Zootaxa. 3682(3): 441–453. DOI:  10.11646/zootaxa.3682.3.5