Emys orbicularis (Linnaeus, 1758) is a polytypic species composed of a number of morphologically defined subspecies (Fritz 1996).
4 Ia kIb
IIa IIb IIc IId IIf 4IIg Jf IIh IIIa IIIb ■o IVa ■n IVb IVc IVd IVe ■0 IVf n IVg IVh Va Vb Vc VIa «VIb VIc VId VIe VIIa t VIIb VIIIa
Fig. 1 Geographical distribution of Emys haplotypes (only natural populations). Some rare haplotypes are not shown. Note that only haplotypes of groups I and II occur naturally North of the Alps
We sequenced the mitochondrial cytochrome b gene of more than 1,100 individuals of pond turtles from about 200 localities, and identified 56 different haplotypes (see Fritz et al., 2007). These could be grouped into nine monophyletic haplotype groups (Figs. 1 and 2).
Group I is composed of ten haplotypes (Ia to Ij). They are distributed in Eastern Europe, in the Aegean region and in Anatolia. Lineage If from Izmir province seems to represent the most ancient surviving haplotype. Only haplotype Ia is found North of the Black Sea and the Crimea - all others occur further South. The considerable variation of group I in Turkey points to the possibility of several refugial areas in the Anatolian peninsula. From there, postglacial expansion most likely occurred both eastwards and westwards, around the Black Sea.
Group II is the sister group of group I. Both constitute the nominate subspecies E. o. orbicularis. Group II occupies an arc-shaped range from Northern Greece across Danube lowlands, parts of Central Europe, and France to North-Eastern Spain. The haplotype with the widest range- IIa- is the direct ancestor of all other haplotypes II, except the more ancestral haplotype IIf which is found in Macedonia. This indicates a possible Pleistocene refugial area in the Southern Balkan Peninsula. From there, haploype IIa spread along the Danube valley, westwards North of the Alps (see Fritz 1996). Haplotype IIb, found in Eastern Germany only, derived from IIa by one mutational step like other local haplotypes (see Fig. 2). The question whether small German populations of haplotype IIa are indigenous relicts or
Fig. 2 TCS parsimony network of the Emys haplotypes. Haplotype group III=Emys trinacris. Open circles symbolize known haplotypes, circle size corresponds to the frequency of haplotypes as detected; dots on lines show single substitution steps between haplotypes (most parsimonious connection)
derived from introduced individuals, is debated among conservationists (see Fritz et al. 2004).
Group III inhabits Sicily and possibly the extreme South of the Italian mainland. As this group is highly differentiated from all others both genetically and morphologically, it has been described as a separate species, E. trinacris (Fritz et al. 2005). It must have remained in isolation for a long time.
Group IV is found around the Adriatic Sea, from Southern Greece to Italy, East of the Apennines. The Northernmost parts of the range are occupied by haplotype IVa only. On the island of Evvia, haplotypes IVa and Ib occur together.
Group V replaces group IV West of the Apennines. It reaches around the coast of the Tyrrhenian Sea to Catalonia and also inhabits Sardinia and Corsica. In Northeastern Spain it occurs in mixed populations with haplotypes IIa, VIa, and VId, in Apulia with IVb and IVd,and in Sicily with IIIa.
Group VI is confined to the Iberian Peninsula and Northwestern Africa. Its most ancestral haplotypes, VIc, and VIf, are found in Morocco. North Africa should therefore be considered as the probable origin of group VI.
Group VII is only found in the Caspian area and Iran, and group VIII is restricted to Southern Anatolia. The geographic origin of group IX is unknown.
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