Triturus anatolicus, Wielstra, B. & Arntzen, J. W., 2016

Wielstra, B. & Arntzen, J. W., 2016, Description of a new species of crested newt, previously subsumed in Triturus ivanbureschi (Amphibia: Caudata: Salamandridae), Zootaxa 4109 (1), pp. 73-80 : 74-79

Triturus anatolicus sp. nov.

Type material. Holotype. RMNH. RENA.48232, an adult male ( Fig. 3 ) from Gölköy, near Kalecik, Turkey (coordinates: 40.077°N, 33.341°E, elevation: 1230 meter a.s.l.; Fig. 4 ), collected 6 April 2014 and donated to Naturalis Biodiversity Center by Kurtuluş Olgun from the Department of Biology at Adnan Menderes University, Aydın, Turkey. Paratypes. Six males ( RMNH. RENA.48233-48238), six females ( RMNH. RENA.48239-48245), and a juvenile ( RMNH. RENA.48246), with collection details identical to the holotype. For imagery, see Fig. 3 and online Appendix 1 and 2.

Diagnosis. The new species is assigned to the genus Triturus because it possesses the characteristics of crested newts (the T. cristatus superspecies), in particular the combination of a denticulated crest (in males in breeding costume), a dark brown dorsal coloration and an orange ventral side covered with black spots. Based on mtDNA sequence data, crested newts from the type locality are firmly placed in the genus Triturus , within the distinct ‘central T. karelinii sensu lato ’ mtDNA lineage (Wielstra et al., 2010). Although identification based on mtDNA is possible across the majority of the range of the new species, mtDNA derived from T. ivanbureschi has introgressed at the western part of the range (Wielstra et al., submitted; Fig. 2 ). The pattern of asymmetric introgression is mirrored by certain individual nuclear DNA markers and we consider this to represent a genomic footprint of hybrid zone movement (Wielstra et al., submitted; Fig. 2 ). As yet only multilocus nuclear DNA sequence data distinguish T. anatolicus sp. nov. unambiguously from T. ivanbureschi – and from T. karelinii , with which both T. anatolicus sp. nov. and T. ivanbureschi were until recently considered conspecific (Wielstra et al., submitted). No morphological features are currently known to distinguish the three species comprising T. karelinii sensu lato. How to separate T. anatolicus sp. nov., T. ivanbureschi and T. karelinii from the other crested newt species is discussed in Wielstra et al. (2013b).

Description of holotype. A relatively robust crested newt, with a broad head (wider than neck) and well developed limbs. Four fingers and five toes. Toes fringed but interdigital webbing absent. Relative length of fingers left 1 <4 <2 <3, right 4 <1 <3 <2 (3 and 4 possibly regenerated). Relative length of toes on both sides 1 <5 <2 <4 <3. Skin granulated on dorsal and lateral sides, tail base and throat; tail and venter smooth. Gular fold inconspicuous. Swollen cloaca with papillae bordering cloacal slit. Denticulated crest, indented over the position of the legs and cloaca. Laterally compressed tail with evident dorsal fin and less conspicuous ventral fin. In life a brownish-blackish base color on the dorsolateral side, with scattered black flecks, most pronounced and marbled on the head. Bluish-white streak along the lateral side of the tail along the caudal vertebrae. A deep-orange ventral side and throat, dotted with small angular black spots; throat spots smaller and denser than belly spots. In the preserved state colors have slightly faded (see online Appendix 1).

The number of rib-bearing pre-sacral vertebrae (NRBV) is 13, as determined from X-ray photographs (see online Appendix 2). The following measurements are in millimeters and have been determined with plastic Vernier calipers. Snout-vent length up to and including the hind-legs 53; Snout-vent length up to and including the cloaca 61; Total length 108; Inter-limb distance 27; Head length 16.2; Head width 10.6; Length of the right arm including the third finger 18.7; Length of the right third finger 5.6; Length of the right leg including the fourth toe 22.1; Length of the right fourth toe 9.5.

Description of paratypes. The morphology of the paratypes resembles that of the holotype in general, but the pattern of black spots on the ventral side is highly variable among individuals (online Appendix 1). Compared to males (such as the holotype), adult females have non-swollen cloacae, lack the denticulated crest and possess a less pronounced tail fin. All paratypes have an NRBV count of 13 except one, which has an NRBV count of 12 ( Table 1 ; online Appendix 2). In Table 1 the same measurements as taken for the holotype are provided for the paratypes.

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.

Figures

FIGURE 1. The two cryptic species comprising Triturus ivanbureschi sensu lato are distributed in Asiatic Turkey and the south-eastern Balkan Peninsula. A rough distribution outline for T. ivanbureschi sensu stricto is shown in green and for T. anatolicus sp. nov. in red. The two taxa meet at a hybrid zone in northwestern Asiatic Turkey. A rough distribution outline for T. karelinii sensu stricto – with which Triturus ivanbureschi sensu lato until recently was considered to be conspecific – is in blue. Records of Triturus newts are absent from most of NE Turkey, suggesting that the ranges of T. anatolicus sp. nov. and T. karelinii sensu stricto do not meet. White dots represent type localities for, from left to right, T. ivanbureschi sensu stricto, T. anatolicus sp. nov. and T. karelinii sensu stricto.

FIGURE 2. Genetic data for Triturus ivanbureschi sensu lato presented in Wielstra et al. (submitted) illustrate the sharp geographical overturn between the genotypes representing its two constituent species. Panel (a) shows the 67 sampled populations as dots with the colored background representing a rough distribution outline of the two species based on nuclear DNA. Populations are colored according to the mtDNA type present; western populations of Triturus anatolicus sp. nov. possess mtDNA of Triturus ivanbureschi sensu stricto. Those populations harboring individuals showing introgression and genetically admixed individuals based on nuclear DNA (as defined below) are highlighted. Panel (b) shows a Structure plot representing Q scores with which the 428 sampled individuals were allocated to two different species (k = 2 was the optimal number of gene pools inferred in the Structure analysis). The individuals are ordered based on the Q score with which they are allocated to T. ivanbureschi sensu stricto, from high to low values. Individuals allocated to their respective species with Q ≥ 0.987 are considered genetically pure. Individuals showing introgression are defined as being allocated to a species with 0.987> Q> 0.85 and genetically admixed individuals as being allocated to either species with Q ≤ 0.85. Those individuals that are not genetically pure are highlighted in panel (b). Note that nuclear introgression is geographically asymmetric.

FIGURE 3. The holotype and one of the paratypes of Triturus anatolicus sp. nov. in life. Lateral (a) and ventral (b) view of a male (below, holotype, RMNH. RENA. 48232) and a female (above, paratype, RMNH. RENA. 48239).

FIGURE 4. The type locality of Triturus anatolicus sp. nov. at Gölköy, Turkey.

Tables

TABLE 1. Number of rib-bearing pre-sacral vertebrae and measurements (in millimeters) for the holotype and paratypes of Triturus anatolicus sp. nov.

Museum number	Sex	Material	NRBV	SVL1	SVL2	TL	ILD
RMNH.RENA.48232	male	holotype	13	53	61	108	27
RMNH.RENA.48233	male	paratype	13	63	71	126	34
RMNH.RENA.48234	male	paratype	12	53	60	110	29
RMNH.RENA.48235	male	paratype	13	53	61	109	26
RMNH.RENA.48236	male	paratype	13	50	58	100	27
RMNH.RENA.48237	male	paratype	13	56	64	115	30
RMNH.RENA.48238	male	paratype	13	53	60	110	29
RMNH.RENA.48239	female	paratype	13	57	62	118	31
RMNH.RENA.48240	female	paratype	13	62	68	133	32
RMNH.RENA.48241	female	paratype	13	58	63	122	33
RMNH.RENA.48242	female	paratype	13	58	62	123	30
RMNH.RENA.48243	female	paratype	13	62	67	117 **	33
RMNH.RENA.48244	female	paratype	13	65	70	131	36
RMNH.RENA.48245	female	paratype	13	56	60	111	31
RMNH.RENA.48246	juvenile	paratype	13	51	55	102	29

continued.