A rangewide phylogeography of Hermann's tortoise, Testudo hermanni (Reptilia: Testudines: Testudinidae): implications for taxonomy

Abstract

Hermann's tortoise (Testudo hermanni), the best‐known western Palaearctic tortoise species, has a rare natural distribution pattern comprising the Mediterranean areas of the Iberian, Apennine, and Balkan Peninsulas, as well as Sicily, Corsica and Sardinia. The western part of this range is traditionally considered habitat for T. h. hermanni, while T. h. boettgeri occurs in the Balkans. Taxonomy of this tortoise has been challenged in recent years, with the two subspecies being considered full species and the central Dalmatian populations of T. h. boettgeri being considered a third species, T. hercegovinensis. Using an mtDNA fragment approximately 1150 bp long (cytochrome b gene and adjacent portion of tRNA‐Thr gene), we investigated mtDNA diversity with regard to contrasting concepts of two subspecies or three species. Seven closely related haplotypes were identified from the western Mediterranean and 15 different, in part much‐differentiated, haplotypes from the Balkans. Western Mediterranean haplotypes differ from Balkan haplotypes in 16–42 mutation steps. One to seven mutation steps occur within western Mediterranean populations. Balkan haplotypes, differing in 1−37 nucleotides, group in parsimony network analysis into three major assemblages that display, in part, a similar degree of differentiation to that of western Mediterranean haplotypes relative to Balkan haplotypes. Rates of sequence evolution are different in both regions, and low divergence, palaeogeography and the fossil record suggest a slower molecular clock in the western Mediterranean. While monophyly in western Mediterranean haplotypes is well‐supported, conflicting evidence is obtained for Balkan haplotypes; maximum parsimony supports monophyly of Balkan haplotypes, but other phylogenetic analyses (Bayesian, ML, ME) indicate Balkan haplotypes could be paraphyletic with respect to the western Mediterranean clade. These results imply a process of differentiation not yet complete despite allopatry in the western Mediterranean and the Balkans, and suggest all populations of T. hermanni are conspecific. In the western Mediterranean no clear geographical pattern in haplotype distribution is found. Distribution of Balkan haplotypes is more structured. One group of similar haplotypes occurs in the eastern Balkans (Bulgaria, Republic of Macedonia, Romania and the Greek regions Evvia, Macedonia, Peloponnese, Thessaly and Thrace). Two distinct haplotypes, differing in eight to nine mutation steps from the most common haplotype of the first group, are confined to the western slope of the Taygetos Mts. in the Peloponnese. Yet another group, connected over between four and 23 mutation steps with haplotypes of the eastern Balkan group, occurs along the western slope of the Dinarid and Pindos Mts. (Istria, Dalmatia, western Greece). Taygetos haplotypes are nested within other haplotypes in all phylogenetic analyses and support for monophyly of the other Balkan groups is at best weak. We conclude that using the traditional two subspecies model should be contin...

Conservation of the endangered Mediterranean tortoise Testudo hermanni hermanni: The contribution of population genetics and historical demography

“…This result is also confirmed by the study of Fritz et al (2006) based on cytochrome b sequences and showing that tortoises from Corsica, Sicily and Sardinia belong to the same lineage. Moreover, in a study based on the mitochondrial cytochrome b and control region genes, Giacalone et al (2009) hypothesized that local extinction occurred in Corsica and Sardinia followed by a subsequent recolonization of tortoises probably originating from Sicily, either by natural oversea dispersal or translocation by humans.…”

“…Further study of Mallorca's tortoise populations would be crucial for a better understanding of the colonization scenarios of the Balearic Islands. It should be mentioned that some evidence of introduction already exists in Mallorca; for example, the study of Fritz et al (2006) revealed the presence of continental and insular haplotypes based on Cyt b sequences.…”

“…According to the high genetic differentiation among the inferred genetic clusters, our results strongly support three genetically isolated ESUs: (i) continental (Albera, Var, peninsular Italy and Minorca1); (ii) island 1 (Corsica, Sardinia and Sicily); and (iii) island 2 (Minorca2). Although we have the information about the reciprocal monophyly of the continental and island 1 ESUs based on the CytB gene (Fritz et al, 2006), a study with a larger number of mitochondrial markers should be carried out in order to verify the monophyly of the third ESU.…”

Complex phylogeography in Rhinoclemmys melanosterna: conflicting mitochondrial and nuclear evidence suggests past hybridization (Testudines: Geoemydidae)

“…The cyt b gene was amplified and sequenced in two fragments overlapping by approximately 300 bp using the primer pairs mt-a-neu3 + mt-E-Rev2 and mt-c-For2 + mt-f-na (Fritz et al 2006;Praschag et al 2007), the 12S rRNA gene with the primers L1091 and H1478 (Kocher et al 1989), and the 16S rRNA gene using the primers 16Sa and 16Sb (Palumbi et al 2002). For the nuclear loci the following primer pairs were used: for Rag 1, Rag1878 and Rag2547 (Le et al 2007); for Rag 2, F2-1 and R2-1 (Le et al 2006); for C-mos, G136 and G137 (Georges et al 1998); for R35, R35Ex1 and R35Ex2 (Fujita et al 2004); and for ODC, the chicken primers of Friesen et al (1999).…”

Activity patterns and habitat preference of eastern Hermann’s tortoise(Testudo hermanni boettgeri) in Serbia

“…Among three tortoise species occurring in Europe (Testudo hermanni, T. graeca, and T. marginata), Hermann's tortoise has the largest regional distribution area (Gasc et al, 1997;Sillero et al, 2014): the western subspecies, T. hermanni hermanni, inhabits parts of the Italian Peninsula, Sardinia, Sicily, Corsica, Provence, the Balearic islands, and the Massif of Alberes, while the eastern subspecies, T. hermanni boettgeri, occupies parts of the Balkan Peninsula, including a number of islands in the eastern Mediterranean region (Fritz et al, 2006) and European Thrace in Turkey (Türkozan et al, 2005). Hermann's tortoise has a regular activity break in winter, which is shorter in the semiarid Mediterranean part of the distribution area (October/November to February/ March) (Willemsen, 1991;Huot-Daubremont and Grenot, 1997) than in more temperate climate areas (October to March/April) (Haxhiu, 1995;Mazzotti et al, 2002).…”