Zoological Studies

Vol. 60, 2021

(update: 2021.01.27; 03.18)

A Different Perspective on Sex Dimorphism in the Adult Hermann’s Tortoise: Geometric Morphometry

Sokol Duro1, Ozan Gündemir2,*, Bektaş Sönmez3, Tefik Jashari4, Tomasz Szara5, Gülsün Pazvant2, and Arben Kambo6


1Faculty of Veterinary Medicine, Agricultural University of Tirana, Tirana, 1000, Albania. E-mail: durosokol@yahoo.com (Duro)
2Department of Anatomy, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, Istanbul, 34500, Turkey. *Correspondence: E-mail: ozan.gundemir@istanbul.edu.tr (Gündemir).
E-mail: gulsun@istanbul.edu.tr (Pazvant)
3Suşehri Timur Karabal Vocational Training School, Cumhuriyet University, Sivas, 58600, Turkey. E-mail: bektass@gmail.com (Sönmez)
4Institute of Graduate Studies, Istanbul University-Cerrahpasa, Istanbul, 34500, Turkey. E-mail: tefikjashari13@gmail.com (Jashari)
5Department of Morphological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Science Warsaw, 02-776, Poland. E-mail: Tomasz_szara@sggw.pl (Szara)
6Department of Economy and Rural Development Policies, Faculty of Economy and Agribusiness, Agriculture University of Tirana, Tirana, 1000, Albania. E-mail: akambo@ubt.edu.al (Kambo)

Received 5 May 2020 / Accepted 20 January 2021
Communicated by Benny K.K. Chan

Eastern Hermann’s tortoise (Testudo hermanni boettgeri) is a subspecies of Hermann’s tortoise (Testudo hermanni) found in Albania. Gender determination is one of the crucial elements in determining the population dynamics in all species. Female and male adult tortoises look different, but these differences can be difficult to distinguish in captivity or when their sex indicators are deformed or injured. Therefore,
the aim of this study was to use indirect and non-invasive methods such as geometric morphometric analysis to determine the sex of adult tortoises. For the geometric morphometry, 17 female and 23 male Hermann’s tortoises were collected and photographed from the hills and mountains around the Tirana district of Albania between August and October 2019. Sexes were discriminated based on geometric morphometry, and plastron shape was a better indicator than carapace shape. In addition, abdominal, femoral and anal scutes on the plastron and the ratio of femoral to pectoral suture lengths were important for the sex distinction. Females had a larger plastron than males; this may have been supported by fecundity selection, because a large plastron suggests more volume in which to store eggs. The femoral and anal scutes were larger in male tortoises, and serve as a stronger base during mating. This study was conducted for adults only, and future studies are needed to determine if these indicators also apply to hatchlings and juveniles.

Key words: Testudo hermanni boettgeri, Sex discriminate, Geometric morphometry, Abdominal scutes, Albania.

Citation: Duro S, Gündemir O, Sönmez B, Jashari T, Szara T, Pazvant G, Kambo A. 2021. A different perspective on sex dimorphism in the adult Hermann’s tortoise: geometric morphometry. Zool Stud 60:9. doi:10.6620/ZS.2021.60-09.