Pelobates syriacus Boettger, 1889

Dufresnes, Christophe, Strachinis, Ilias, Tzoras, Elias, Litvinchuk, Spartak N. & Denoel, Mathieu, 2019, Call a spade a spade: taxonomy and distribution of Pelobates, with description of a new Balkan endemic, ZooKeys 859, pp. 131-158 : 142

Pelobates syriacus Boettger, 1889

Diagnosis.

Large spadefoot with whitish metatarsal spades and a flat skull. Webbing of the hind feet less developed than in P. fuscus and P. vespertinus . Sexes of similar size (Fig. 2). Coloration can be gray, yellow, greenish but rarely brown; orange dots often present, but not as abundant and marked as in some individuals of P. fuscus , P. vespertinus , or P. balcanicus (Fig. 4). Based on populations of P. syriacus boettgeri , average SVL = 68 mm (range: 40-92) for females (n = 5 populations) and 69 mm (57-83 mm) for males (n = 4 populations) (Suppl. material 1, Table S1; Fig. 2). The karyotype consists of seven large and six small pairs of two-armed chromosomes ( Uğurtaş et al. 2001, from P. s. boettgeri ). Centromeric C-bands are obvious in pairs 8 and 10 and telomeric Q-bands in the long arms of pairs 9 and 10 ( Schmid 1979; Schmid et al. 1987). NORs are in the short arm of pair 7 ( Schmid 1982; Schmid et al. 1987). The nuclear DNA content averages 8.2 pg ( Litvinchuk et al. 2013; data from P. s. boettgeri ).

Taxonomy.

Described from the Levant region as Pelobates syriacus Boettger, 1889; type locality: "Haiffa in Syrien" (Haifa), Israel; type: SMF 1437.1a ( Boettger 1892), subsequently designated as lectotype SMF 1722 ( Mertens 1967). Other nomina proposed apply to P. s. boettgeri and P. balcanicus (see below).

Distribution.

Scattered distribution; mainly present in the Middle East with 0-2000 m elevation a.s.l. ( Agasyan et al. 2009b; Uğurtas 2001; Džukić et al. 2008; Sofianidou 2012) (Fig. 1). The nominate subspecies P. syriacus syriacus inhabits the southern part of the distribution in the Levant, from the Syrian coast at the border of Lebanon to the southern Israeli coast, as well as in south-western Syria ( Boettger 1889; Munwes et al. 2010; Sofianidou 2012). It may be extinct from western Jordan ( Agasyan et al. 2009b; Disi and Amr 2010). The subspecies P. syriacus boettgeri occupies the remaining ranges. In the west, it is present in western Turkey and along the Aegean coastline. It also occurs in European Turkey and probably southeastern Bulgaria. Alternatively, the latter populations could belong to P. balcanicus , notably along the Maritsa River, and identification is pending molecular analyses. The presence of P. syriacus is also documented on the Greek islands of Limnos, Lesbos, and Kos ( Sofianidou 2012; Strachinis and Roussos 2016). Its central distribution is poorly known and therefore not well delineated, with several isolates described in Turkey, both along the Black and Mediterranean sea coasts, as well as the central parts of Anatolia. In the northeast, P. syriacus reaches the southern slopes of the Caucasus, from Georgia to Azerbaijan. The northernmost records are in Dagestan, on the west coast of the Caspian Sea, where it meets P. vespertinus ( Mazanaeva and Askenderov 2007). Further east, it is present along the southern shores of the Caspian Sea in Iran (eastern limit in Golestan; Kamali and Malekzadeh 2013). IUCN status: Not Evaluated; considered Least Concern when grouped with P. balcanicus ( Agasyan et al. 2009b).

Diversity.

Using mtDNA and genomic data, Dufresnes et al. (2019b) evidenced a Pleistocene split between the Levant ( P. s. syriacus ) and the rest of the range ( P. s. boettgeri ; see below). Within both subspecies, populations are weakly differentiated despite their present-day fragmentation (see also Munwes et al. 2010 for P. s. syriacus ). Populations from the Caucasus ( P. s. boettgeri ) differs from Anatolian ones at nuclear, but not mitochondrial markers. In the Lesser Caucasus and southern Turkey, P. s. boettgeri features traces of past gene flow with P. s. syriacus . Iranian populations have not been examined with genetic tools and could bear cryptic diversity.