Herpetology Notes, volume 14: 649-651 (2021) (published online on 10 April 2021) Dicephalism in Aesculapian snake, Zamenis longissimus (Serpentes, Colubridae) from Montenegro Slađana Gvozdenović1,*, Vuk Iković1, and Marko Nikolić2 Dicephalism, also known as axial bifurcation or caught by a domestic cat but was not collected, so the somatodichotomy, is a phenomenon when an animal description of the specimen’s morphology is given have two heads. According to Devkota et al. (2020), based on photographs. dicephalism rarely occurs in nature, while most reports The specimen was alive, juvenile, with well developed, involve snakes. According to Devkota et al. (2020), completely separated heads – prodichotomy and both up until now, the number of verified and recorded heads were with two eyes (Fig. 2). The individual was cases of dicephalism in snakes is 1987. The most about 15–20 cm in length. The colour pattern was as common types of dicephalism are: prodichotomy usual in aesculapian juveniles, several rows of small – complete separation and development of two heads dark spots on the dorsal side and a boldly marked head and craniodichotomy – heads are not entirely separated, with yellow blotch on sides of both heads (Fig. 2). After has two snouts and either three or four eyes, depending locals took photographs, the cat took the snake away. It upon the separation of the heads (Wallach and Herman, is not known if the snake survived. 2019). Dicephalism can be a result of both, genetic and This is the second documented finding of two-headed environmental factors. Wallach (2007) marked different snakes in Montenegro. The first finding was a juvenile causes of bicephaly: incomplete division of a single Four-lined snake (Elaphe quatuorlineata) in Dobrota, embryo; partial fusion of two embryos; abnormally low Kotor (Gvozdenović and Čavor, 2015). In the literature or high temperatures during incubation or gestation; there are two records of dicephalism in the Aesculapian regeneration after an embryonic lesion; anoxia during snake from Balkan Peninsula, one record from Serbia embryonic development; toxic effects of metabolic and other one from Croatia (Radovanović, 1957; secretions during a prolonged sojourn in the oviduct; Jovanović, 1997, 2011). The specimens from Croatia inbreeding depression from small population gene was also juvenile, about 20 cm in length and also an pools, back-crossing, designer morphs, and albinos; example of symmetric dicephaly. The two heads in this hybridisation; environmental pollution; chemical toxins specimens were connected via soft tissue near the ear in captivity or exposure to radiation. canals, fully developed, functional, and apparently co- This paper presents the second finding of dicephalic snake in Montenegro. A two-headed Aesculapian snake, Zamenis longissimus (Laurenti, 1768) was found on 22 November 2020. The snake was recorded and photographed by locals in Sutomore (settlement Zgrade), municipality of Bar (42.1514ºN, 19.0389ºE; approximate elevation 60 m, Fig. 1). It had been 1 Montenegrin Ecologists Society, Bulevar Svetog Petra Cetinjskog 73, 81000 Podgorica, Montenegro. 2 University of Novi Sad, Faculty of Science, Department of Biology and Ecology, 21000 Novi Sad, Serbia. * Corresponding author. E-mail: sladjana87gvozdenovic@ gmail.com Figure 1. Map with marked locality (red circle) where the © 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. juvenile dicephalic Zamenis longissimus was found. 650 Slađana Gvozdenović et al. Figure 2. The juvenile dicephalic Zamenis longissimus from Sutomore, Montenegro. Photograph by Ivan Zgradić. dominant in controlling the behaviour of the animal References (Jovanović, 2011). Cavigioli, L., Meier, G., Mischischia, N. (2016): Another case of The majority of dicephalic snakes are unable to dicephalism in Vipera aspis francisciredi (Laurenti, 1768), from survive in the wild due to problems related to feeding northern Italy. Herpetozoa 29(1/2): 85–86. and escaping predation (Devkota et al., 2020), which De Albuquerque, N.R., Piatti, L., Wallach, V. (2013): Dicephalism is probably a reason why most reported cases of in the green racer snake, Philodryas patagoniensis (Serpentes, dicephalism refer to juvenile and newly hatched snakes Colubridae), from southeastern Brazil. Herpetology Notes 6(1): (Jovanović, 2011; De Albuquerque et al., 2013; Pezdirc 85–87. Devkota, K., Ghimire, A., Thapamagar, C., Wallach, V., Wojnowski, et al., 2013; Gvozdenović and Čavor, 2015; Cavigioli D. (2020): First record of dicephalism in the Common Krait, et al., 2016; Wallach and Herman, 2019; Devkota et al., Bungarus caeruleus (Schneider 1801), from Nepal. IRCF 2020). Two-headed snakes can survive for many years Reptiles & Amphibians 26(3): 226–229. in captivity (Wallach, 2007), because feeding can be Gvozdenović, S., Čavor, N. (2015): First record of dicephalism artificially controlled and there is no predation. in the Four-lined snake Elaphe quatuorlineata Lacépède, 1789 (Serpentes: Colubridae) from Montenegro. Natura Sloveniae Acknowledgements. We thank the local people from settlement 17(1): 49–50. Zgrade in Sutomore, municipality of Bar, for providing us with Jovanović, M. (1997): Bikefalne zmije. Desbilten 6: 27–30. (In: this finding and their photographs and for giving us permission Serbian). to publish the record. Jovanović, M. (2011): Dicephalic snakes from the north-eastern Balkan Peninsula. Available at https://www.academia.edu/ Dicephalism in Aesculapian snake, Zamenis longissimus from Montenegro 651 8403620/Dicephalic_Snakes_from_the_North_Eastern_ Balkan_Peninsula. Accessed on 25 December 2020. 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