Greek tortoise
The Greek tortoise (Testudo graeca), also known as the spur-thighed tortoise, is a medium-sized species of tortoise in the family Testudinidae, characterized by prominent spurs on its hind thighs and a domed carapace typically measuring 15–25 cm in length, though some subspecies reach up to 33 cm and 7 kg in weight.[1][2]
Native to a broad distribution spanning southern Europe (including Greece and the Balkans), North Africa from Morocco to Egypt, and southwestern Asia through Turkey to the Caucasus and Iran, it occupies varied arid and semi-arid habitats such as scrublands, grasslands, pine woodlands, and semi-deserts, where it forages primarily on grasses, herbs, and flowers.[3][4]
Renowned for exceptional longevity, with verified lifespans exceeding 100 years and records up to 127 years in captivity, T. graeca reaches sexual maturity at 11–14 years and produces clutches of 1–5 eggs annually during a single breeding season.[5][6] Classified as Vulnerable on the IUCN Red List due to habitat fragmentation, overcollection for the pet trade, and predation, populations have declined across much of its range, prompting protections under CITES Appendix II.[1][7][3]
Taxonomy and Phylogeny
Scientific Classification and Etymology
The Greek tortoise (Testudo graeca) is classified in the order Testudines, family Testudinidae, genus Testudo.[8]- Kingdom: Animalia
- Phylum: Chordata
- Class: Reptilia[9]
- Order: Testudines[9]
- Family: Testudinidae[8]
- Genus: Testudo[10]
- Species: T. graeca[10]
Subspecies and Genetic Diversity
The spur-thighed tortoise, Testudo graeca, displays substantial genetic and morphological variation across its range, resulting in the description of numerous subspecies, though taxonomic boundaries remain debated due to overlapping traits and incomplete genetic validation. Mitochondrial DNA analyses, including sequences from the 12S rRNA and cytochrome b genes, reveal high haplotype diversity, with 13 distinct haplotypes identified among 158 North African and Middle Eastern specimens, indicating ancient phylogeographic splits between western (North African) and eastern (Anatolian to Caucasian) clades dating back potentially hundreds of thousands of years.[12][13] These studies underscore low gene flow across geographic barriers like the Atlas Mountains and Anatolian highlands, with western populations exhibiting unique haplotypes not shared with eastern ones, such as T. g. graeca and T. g. ibera.[14] In North Africa, genetic surveys of Moroccan populations using partial 12S rRNA sequences from 16 individuals across four sites demonstrated moderate overall diversity (nucleotide diversity π = 0.012), but with pronounced between-population differentiation (pairwise F_ST up to 0.89), suggesting isolation by habitat fragmentation in semi-arid regions.[15] Eastern clades show even greater divergence, with cytochrome b phylogenies rooting T. graeca lineages separately from outgroups like T. kleinmanni, and haplotype networks clustering T. g. ibera (Anatolia and Balkans) distinctly from Iranian or Caucasian forms.[13] This supports recognition of eastern subspecies such as T. g. armeniaca, T. g. buxtoni, T. g. ibera, T. g. terrestris, and T. g. zarudnyi, each adapted to local conditions like xeric steppes or montane scrub, though some authorities propose elevating them to species based on genetic distances exceeding 5% in mtDNA.[16] Western North African subspecies include T. g. nabeulensis (Tunisia and Libya) and T. g. soussensis (southwest Morocco), characterized by smaller size and brighter carapace coloration, with recent Libyan populations reassigned as T. g. tripolitania based on spur morphology and geographic isolation.[17] Human activities, including pet trade and introductions, have introduced eastern genotypes to western sites, such as Doñana National Park in Spain, where cyt b diversity is reduced (only two haplotypes detected) and hybridization erodes native T. g. graeca lineages.[18] Overall, while mtDNA highlights cryptic diversity vulnerable to habitat loss and collection—e.g., IUCN Vulnerable status for eastern clades—nuclear markers are needed to resolve ongoing hybridization and effective population sizes, as mtDNA alone may overestimate divergence due to maternal inheritance.[19]| Clade | Example Subspecies | Key Genetic Markers | Distribution |
|---|---|---|---|
| Western | T. g. graeca, T. g. nabeulensis | Unique 12S rRNA haplotypes; low π within sites | North Africa (Morocco to Libya)[15][12] |
| Eastern | T. g. ibera, T. g. terrestris | Distinct cyt b clades; high inter-lineage divergence | Anatolia, Caucasus, Iran[13][16] |