TWO NEW CASES OF PAEDOMORPHOSIS IN THE CAUCASIAN NEWTS: Ommatotriton ophryticus (THE FIRST RECORD) AND Lissotriton vulgaris lantzi Dmitry V. Skorinov, 1 Oleg Novikov, 2 Leo J. Borkin, 2 and Spartak N. Litvinchuk 1 Submitted April 8, 2008. A female of the Caucasian banded newt, Ommatotriton ophryticus ophryticus (Berthold, 1846) with well-devel- oped external gills was found in Malaya Ritsa Lake, Abkhazia, the western Caucasus. It is the first record of paedomorphosis for the genus. A paedomorphic Lissotriton vulgaris lantzi (Wolterstorff, 1914) and an over- wintering larva of Triturus karelinii (Strauch, 1870) were captured in the settlement Machary, the eastern vicinity of Sukhum Town, Abkhazia. The geographic distribution of paedomorphic newts and overwintering larvae of Ommatotriton ophryticus ophryticus and Lissotriton vulgaris lantzi are mapped. Keywords: Amphibia, Salamandridae, paedomorphosis, Ommatotriton ophryticus, Lissotriton vulgaris lantzi, the Caucasus. The paedomorphosis (or neoteny according to some authors) as a particular phenomenon of heterochronic development of animals is widely distributed among urodelan amphibians. In the family Salamandridae the paedomorphosis is known for the newt genera Noto- phthalmus, Pleurodeles, Lissotriton, Mesotriton, and Triturus. Since the 19 th century, the majority of cases (single individuals and populations) were registered in the species of Mesotriton and Lissotriton, formerly as- signed to the genus Triturus sensu lato (Litvinchuk et al., 1996; Denoël, 2007). However, no record of paedo- morphic newts of the genus Ommatotriton was pub- lished. Recently, overwintering larvae of the Caucasian banded newt were observed in Abkhazia, the western Caucasus (Malandziya and Vasilenko, 2002). We recog- nized two species of the genus Ommatotriton Gray, 1850 distributed in Middle Asia and the Caucasus, namely: O. ophryticus (Berthold, 1846) and O. vittatus (Gray, 1835), each with two subspecies (Litvinchuk and Bor- kin, 2009). Therefore, the Caucasian populations should be treated as O. ophryticus ophryticus (Berthold, 1846). In spring 2007, a paedomorhic female O. o. ophryti- cus was found by Oleg Novikov in Malaya Ritsa Lake, Ritsa Relic National Park, Abkhazia, among numerous normal adult newts. The animal (total length 103.7 mm, body length 54.8 mm) reached, in fact, the same size as transformed newts (Fig. 1). The female had well-devel- oped external gills, even dorsal fin and a little lighter coloration (Figs. 1 and 2). The newt was taken to the laboratory in Krasnograd Town, Kharkov Province, Ukraine, where it lived about one month. Unfortunately, its death happened in the summer of the same year (2007), without obvious causes. Currently, the specimen is keeping in the collections of the Department of Herpe- tology, Zoological Institute, Russian Academy of Sci- ences, St. Petersburg. As a rule, paedomorphic newts were observed in oligotrophic water bodies with abrupt shores. Such wa- ter bodies also provided sufficient amount of food both for adults and larvae, and lacked possible predators. Importantly, a water body must be not frozen down at bottom in winter and to dry up in summer (Litvinchuk et al., 1996; Denoël, 2007). Malaya Ritsa Lake demon- strates all these characters. Indeed, this oligotrophic lake with abrupt shores is situated at the altitude of 1235 m a.s.l. and surrounded by the primary beech forest. The lake length is about 500 m, the maximum width is 275 m, and the maximum depth is 76 m. The water in the lake is quite cold and very transparent because the water level is supported by thawed influx. In addition, Malaya Ritsa Lake contains no fish (Chikovani et al., 1990). 1026-2296/2009/1601-0016 © 2009 Folium Publishing Company Russian Journal of Herpetology Vol. 16, No. 1, 2009, pp. 16 – 18 1 Institute of Cytology, Russian Academy of Sciences, Tikhoretskiy pr. 4, St. Petersburg 194064, Russia. 2 Zoological Institute, Russian Academy of Sciences, Universitet- skaya nab. 1, St. Petersburg 199034, Russia.