The dice snake (Natrix tessellata) is a Eurasian nonvenomous snake belonging to the family Colubridae, subfamily Natricinae. It is also called water snake.[3]
Brief description
Illustration of dice snake (top) and grass snake (Natrix natrix) including undersideA dice snake in Umbria, Italy
Females are bigger than males. Their typical size is 1.0–1.3 m (39–51 in) long. Their color may vary from greyish green to brownish or almost black, with dark spots on the back. The belly is sometimes vividly coloured in yellow or orange, with black spots, very similar to dice, hence the name.
Biology
Living mainly near rivers, streams and lakes, it frequently feeds on fish. Sometimes, it feeds also on amphibians such as frogs, toads, and tadpoles.
Classified as nonvenomous, N. tessellata produces a potent antihemorrhagin in its serum[4] and has been said to produce a neurotoxin through a gland in its mouth.[5] As a defence, it spreads a very bad-smelling secretion from its cloaca. Another defence mechanism is thanatosis, playing dead.
During the mating season (March–May), they congregate in large groups. Egg-laying is usually in July, and one clutch consists of 10–30 eggs. The young snakes hatch in early September.
N. tessellataDice snake observed along Caspian Sea in northern Iran
Dice snakes hibernate from October to April in dry holes near the water.
One of the most numerous populations lives in the vicinity of the ruins of Histria, in the Dobruja region, Romania. This population has been recently discovered to be threatened by a parasiticnematode of the genus Eustrongylides. Since 2005, the population from Histria has been receiving researchers' attention. For example, a joint Romanian–Swedish–Czech research program is focused on population biology studies and parasitic threats of this unique coastal population. An overview on Biology, Distribution and Conservation is given by Mebert (2011).[7]
References
^Mebert, K.; Amr, Z.S.S.; Al Johany, A.M.H.; Aloufi, A.A.H.; Jiang, J.; Meyer, A.; Sterijovski, B.; Baha El Din, S.; Pleguezuelos, J.; Sá-Sousa, P.; Corti, C.; Ajtic, R.; Tuniyev, S.; Orlov, N.L.; Ananjeva, N.B.; Cogălniceanu, D.; Andrén, C.; Crnobrnja-Isailović, J.; Aghasyan, A.; Avci, A.; Tuniyev, B.; Lymberakis, P.; Wilkinson, J.; Üzüm, N.; Podloucky, R.; Kaya, U.; Vogrin, M.; Pérez Mellado, V.; Cheylan, M.; Nettmann, H.K.; De Haan, C.C.; Schmidt, B.; Lau, M.; Borkin, L.; Milto, K.; Golynsky, E.; Belouskova, A.; Rustamov, A; Nuridjanov, D.; Munkhbayar, K. (2021). "Natrix tessellata". IUCN Red List of Threatened Species. 2021: e.T157256A745071. doi:10.2305/IUCN.UK.2021-2.RLTS.T157256A745071.en. Retrieved 21 February 2022.
^Boulenger, G.A. 1893. Catalogue of the Snakes in the British Museum (Natural History), Volume I. London. pp. 233-234
^Borkow, Gadi; Gutierrez, Jose Maria; Ovadia, Michael (1994-12-15). "A potent antihemorrhagin in the serum of the non-poisonous water snake Natrix tessellata: isolation, characterisation and mechanism of neutralisation". Biochimica et Biophysica Acta (BBA) - General Subjects. 1201 (3): 482–490. doi:10.1016/0304-4165(94)90080-9. ISSN0304-4165. PMID7803481.
^Mebert, Konrad (ed.): The Dice Snake, Natrix tessellata: Biology, Distribution and Conservation of a Palaearctic Species. Mertensiella 18, 2011, pp. 1-456.
