Darevskia unisexualis (Unisexual Lizard / Ağrı Kertenkelesi) from Aşkale, ERZURUM.
I am presenting a special lizard from Aşkale (Erzurum province, E Anatolia), which I’ve photographed during my E Anatolian trip. It is special because its population consist of only females and they show an asexual reproduction without fertilization by males. This event is called as Parthenogenesis. Darevskia (Eastern Rock Lizards, formerly Lacerta saxicola komplex) genus includes lizards possessing the two following features found only in a minority of other lacertid lizards: 27–28 presacral vertebrae in males, one postnasal scale. Other more widely distributed features include: supraocular osteoderms (bony plates) fenestrated or intact in adults, usually seven premaxillary teeth, inscriptional ribs present in some species, tail often brightly coloured in hatchlings, hemipenial microornamentation of crown-shaped tubercles. A few species of Darevskia are parthenogenetic [from the Greek παρθένος parthenos, "virgin", + γένεσις genesis, "creation") is an asexual form of reproduction found in females where growth and development of embryos occurs without fertilization by males], and males of some bite the thigh of the female during copulation. Approx. 27 species was described belonging to this genus, and of these aprrox. 17 species are distributed in Anatolia. The general distribution of the genus representatives is restricted to Caucasus region, Crimea and N and E Turkey, eastwards to Alborz mountains of Iran and to Kopet Dagh on Iran-Turkmenistan border; one species (D. praticola- Meadow Lizard) reaching the eastern Balkan peninsula.
Here you can see an adult individual of the Unisexual Lizard who has a total length (including the tail part) of approx. 20 cm. This species has typically a Rostral plate in contact with Frontonasal plate, distinguishing it obviously from the similar ones. Whereas in all other Darevskia species the Rostral plate usually is separated by nasal plates. The distribution range of the species is divided into several isolated populations within the northern and central high-mountain Armenia and the adjacent regions of eastern Turkey, from where along the valley of Kura River this lizard penetrates into southern Georgia. Outside of the Caucasus it occurs in the valley of the river Aras in eastern Turkey. In Turkey, it is found in Erzurum, Ardahan & Ağrı- with a vertical distribution to 2000 m. Clutches usually consisting of about 5 eggs.
References: 1. Göçmen, B. (Unpub. results). The results of herpetological trips. 2. Budak, A. & Göçmen, B. (2005). Herpetology. Ege Üniversitesi Fen Fakültesi Kitaplar Serisi, No. 194, Ege Üniversitesi Basimevi, Bornova-Izmir, 226 pp. [2nd Edition, 2008].
|Created on||Thursday 30 July 2009|
|Posted on||Thursday 20 January 2011|
|Tags||Erzurum, TURKEY / TÜRKİYE|