Adult, Psili Ammos, Serifos, Greece, July 26, 2011
(Photo by Paolo Mazzei)

Adult, Psili Ammos, Serifos, Greece, July 26, 2011
(Photo by Paolo Mazzei)

Adult, Lake Mikri Prespa, Greece, May 10, 2004
(Photo by Jeroen Speybroeck, Herpetofauna of Europe)

Adult, Lake Volvi, Thessaloniki, Greece, March 2001
(Photo by Jan Van Der Voort)

Adult, Lake Volvi, Thessaloniki, Greece, March 2001
(Photo by Jan Van Der Voort)

Adult, Lake Volvi, Thessaloniki, Greece, March 2001
(Photo by Jan Van Der Voort)

Adult, Doriskos, Evros, Greece, April 2001
(Photo by Jan Van Der Voort)

Adult, Cape Kaliakra, Dobrich, Bulgaria, May 1998
(Photo by Jan Van Der Voort)

Young, Dadia Forest, Evros, Greece, April 2001
(Photo by Jan Van Der Voort)

Adult, Babadag Forest, Tulcea, Romania, April 2002
(Photo by Jan Van Der Voort)

Adult, Babadag Forest, Tulcea, Romania, April 2002
(Photo by Jan Van Der Voort)

Adult, Macin Hills, Tulcea, Romania, April 2002
(Photo by Jan Van Der Voort)

Adult, Macin Hills, Tulcea, Romania, April 2002
(Photo by Jan Van Der Voort)

Adult, Nestos delta, Keramoti, Greece, May 1, 2004
(Photo by Jeroen Speybroeck, Herpetofauna of Europe)

Young, 15 km E of Lamia, Greece
(Photo by Mario Schweiger, VipersGarden)