- Tunisian Spur-thighed Tortoise
Taxobox
name = Tunisian Spur-thighed tortoise
image_width = 240px
image_caption = Note yellow patch above eye
regnum =Animal ia
phylum =Chordata
classis =Sauropsida
ordo =Testudines
subordo =Cryptodira
familia =Testudinidae
genus = "Testudo"
species = "T. graeca" (but see text)
subspecies = "T. g. nabeulensis"
trinomial = "Testudo graeca nabeulensis"
trinomial_authority = (Highfield, 1990Verify source|date=November 2007)
synonyms ="Furculachelys nabeulensis" Highfield, 1990Verify source|date=November 2007"Testudo nabeulensis" (Highfield, 1990Verify source|date=November 2007) (but see text)The Tunisian Spur-thighed Tortoise (see also below) belongs to the
spur-thighed tortoise group. It was originally described as a newspecies in 1990, and even placed in a distinctgenus . The spur-thighed or "Greek" tortoises are usually collectively referred to as "Testudo graeca", but this covers a wide variety ofsubspecies that have very differentecological and morphological characteristics and appear to comprise at least 3phylogenetic lineagesvan der Kuyl "et al." (2005)] . As its name implies, it is found inTunisia and nearbyAlgeria (but see also "Systematics" below).Description and ecology
The Tunisian Spur-thighed Tortoise is a relatively small
tortoise . The adult males usually have a carapace that seldom exceeds 13 cm (about 4.5 in), whilst the adult females' carapax is no more than 16.5 cm (some 4 in) long. The geographically closest population of the "Testudo graeca" group, fromMorocco , is decidedly larger.These tortoises are among the most brightly coloured
taxa of the spur-thighed complex, with a light yellowcarapace with strong black markings in thescute centres. Theplastron also has bold colour pattern. Upon the top of the head, right between the eyes, there is a distinct yellowish spot.Tunisian Spur-thighed Tortoises are popular as a
pet due to the attractive coloration and small size. They are a bit more delicate than their larger relatives and though their care is not particularly difficult, they are not ideal pets for those who have no experience at all in keeping tortoises. Coming from tropicalsemiarid habitat, do nothibernate and an attempt to have them do so will cause fatality. This does actually make their care easier for people in warmer regions, but intemperate climates they require a well-heated and amply litterrarium even in winter.ystematics
The genus "Furculachelys" was established for this taxon and "White's Tortoise" (or "Selborne tortoise"). The latter seems to be a local morph rather than a distinct subspecies however. In any case, separating a form that is in all respects a perfectly ordinary "Testudo", compared to more distinct species such as the
Russian Tortoise seems to be gross oversplitting, making "Testudo"paraphyletic .Treatment as a distinct genus is also not supported by
mtDNA 12S rRNA haplotype analysis. However, these results still seem to confirm that the Tunisian Spur-thighed Tortoise constitutes a well-marked lineage of spur-thighed tortoises. The "Testudo graeca" complex is likely to be split into (at least) 3 species in the near future; the easternMaghreb populations would remain in "T. graeca" in this case. Consequently, thescientific name that agrees best with the collected evidence would presently be "Testudo graeca nabeulensis". As said above however, apart from the Balkans and Eastern populations of the "T. graeca" complex the present taxon seems to be quite distinct too. As the former two lineages will eventually come to represent good species, perhaps the Tunisian Spur-thighed Tortoise might also be regarded as specifically distinct.There are some unresolved questions regarding the relationships of two populations of spur-thighed tortoises. The
Libya n population was described as "Testudo flavominimaralis" in the same publication which established "F." nabeulensis". These two are rather similar to each other and as noted above, the separation of "Furculachelys" is highly dubious on these grounds alone. If the eastern Maghreb tortoises are regarded as a distinct species, it is not unlikely that the Libyan population is united with them as a subspecies.On
Sardinia , there exists a population of spur-thighed tortoises which share the small size, the yellow head spot, and the contrasting markings with the Tunisian population. Theirtaxonomical status is enigmatic, as is their very existence on the island, separated fromNorth Africa by a considerable stretch of theMediterranean which tortoises are hardly able to cross. There is a distinct local form of theMarginated Tortoise on the island however, and that seems to have originated from a deliberate introduction by humans, perhaps by Greek or Roman landowners in theclassical antiquity [Fritz "et al." (2005)] . While the local Marginated Tortoises show evidence of pronouncedgenetic drift and may thus justifiably regarded as a subspecies despite the absence oflineage sorting , the spur-thighed tortoises of Sardinia are probably best considered an introduced population not yet worthy of taxonomical separation pending further research.Nonetheless, because the present taxon may well turn out not to be limited to Tunisia and its immediate surroundings, the alternative common name Nabeul Tortoise might actually be preferrable. It is a literal translation of the
scientific name and honors the Tunisian city ofNabeul where the type material was collected. Even if this fact were generally known, it is not very likely that anyone would believe that these animals are endemic to a single city.Footnotes
References
* (2005): Environmentally caused dwarfism or a valid species - Is Testudo weissingeri Bour, 1996 a distinct evolutionary lineage? New evidence from mitochondrial and nuclear genomic markers. "Mol. Phyl. Evol." 37(2): 389–401. doi|10.1016/j.ympev.2005.03.007
* (2005): Mitochondrial haplotype diversity in the tortoise species "Testudo graeca" from North Africa and the Middle East. "BMC Evol. Biol." 5: 29. doi|10.1186/1471-2148-5-29 (HTML/PDF fulltext + supplementary material)External links
* [http://myweb.tiscali.co.uk/cheloniauk/FNABS.htm A website about Tunisian Tortoises]
Wikimedia Foundation. 2010.