dice snake
{{Short description|Species of snake}}
{{speciesbox
| image = Natrix tessellata capturing a Gobius fish - 20060710.jpg
| image_caption = Eating a goby
| status = LC
| status_system = IUCN3.1
| genus = Natrix
| species = tessellata
| authority = (Laurenti, 1768)
| synonyms = Coronella tessellata Laurenti, 1768
Coluber tessellatus Bonnaterre, 1790
Tropidonotus tessellatus, part., Wagler, 1830
Natrix tessellata Bonaparte, 1834
Tropidonotus tessellatus Boulenger, 1893Boulenger, G.A. 1893. Catalogue of the Snakes in the British Museum (Natural History), Volume I. London. pp. 233-234
| range_map = Natrix tessellata distribution map.svg
| range_map_caption = Distribution of Natrix tessellata
}}
The dice snake (Natrix tessellata) or water snake{{cite journal |last1=Guicking |first1=Daniela |last2=Joger |first2=Ulrich |last3=Wink |first3=Michael |title=Cryptic diversity in a Eurasian water snake (Natrix tessellata, Serpentes: Colubridae): Evidence from mitochondrial sequence data and nuclear ISSR-PCR fingerprinting |journal=Organisms Diversity & Evolution |date=25 August 2009 |volume=9 |issue=3 |pages=201–214 |doi=10.1016/j.ode.2009.03.001 |doi-access=free |bibcode=2009ODivE...9..201G }} is a Eurasian nonvenomous snake in the family Colubridae, subfamily Natricinae. Its average length is {{convert|1.0|-|1.3|m|in|abbr=on}}. Body 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.
Ecology
Living mainly near rivers, streams and lakes, it frequently feeds on fish. Sometimes, it feeds also on amphibians such as frogs, toads, and tadpoles. In one instance, a dice snake was even observed trying to feed on an olm (Proteus anguinus) that had been flushed from a cave in Bosnia and Herzegovina following heavy rains.{{cite journal |last1=Lewarne |first1=Brian |last2=Allain |first2=Steven J. R. |date=2023 |title=Attempted predation of a cave olm Proteus anguinus by a dice water snake Natrix tessellata, in Bosnia and Herzegovina |journal= Herpetological Bulletin |volume= 165 |pages=34–35 |doi=10.33256/hb165.3435 |url=https://www.thebhs.org/publications/the-herpetological-bulletin/issue-number-165-autumn-2023/3862-11-attempted-predation-of-a-cave-olm-i-proteus-anguinus-i-by-a-dice-water-snake-i-natrix-tessellata-i-in-bosnia-and-herzegovina|doi-access=free }} However, the snake was far too small to be able to consume the olm.
While considered nonvenomous, N. tessellata produces a potent antihemorrhagin in its serum.{{cite journal |last1=Borkow |first1=Gadi |last2=Gutierrez |first2=Jose Maria |last3=Ovadia |first3=Michael |title=A potent antihemorrhagin in the serum of the non-poisonous water snake Natrix tessellata: isolation, characterization and mechanism of neutralization |journal=Biochimica et Biophysica Acta (BBA) - General Subjects |date=December 1994 |volume=1201 |issue=3 |pages=482–490 |doi=10.1016/0304-4165(94)90080-9 |pmid=7803481 |hdl=10669/29234 |hdl-access=free }} As a defence, it spreads a very bad-smelling secretion from its cloaca. Another defence mechanism is thanatosis, playing dead.{{cn|date=August 2024}}
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. Dice snakes hibernate from October to April in dry holes near the water.{{cn|date=August 2024}}
{{Multiple image
| image1 = Schlange frist Fisch.jpg
| image2 = Pumpkinseed, Dubravice, Skradin, Chorvatsko imported from iNaturalist photo 167015144.jpg
| total_width = 600
| align = center
| caption1 = Eating a European perch
| caption2 = Eating a young pumpkinseed sunfish
}}
Distribution
Conservation
The species is considered to be of Least Concern in its overall range, although local populations may be more sensitive. For example, it is considered Critically Endangered in the Czech Republic, mostly due to destruction of habitats and the introduction of invasive American mink.{{cite journal |last1=Chmelař |first1=Jan |last2=Civiš |first2=Petr |last3=Fischer |first3=David |last4=Frynta |first4=Daniel |last5=Jeřábková |first5=Lenka |last6=Rudolfová |first6=Veronika |last7=Rehák |first7=Ivan |title=Protecting isolated reptile populations outside their main area of distribution: a predictive model of the Dice snake, Natrix tessellata, distribution in the Czech Republic |journal=Biodiversity Data Journal |date=28 December 2023 |volume=11 |pages=e114790 |doi=10.3897/BDJ.11.e114790 |doi-access=free |pmid=38188184 |pmc=10767748 }}
Gallery
File:Dürigen, 1897, T07.JPG|Illustration of dice snake (top) and grass snake (Natrix natrix) including underside
File:Dicesnake umbriaitaly.jpg|In Umbria, Italy
References
{{Reflist}}
External links
{{Commons category}}
{{Taxonbar|from=Q750237}}
{{Authority control}}
Category:Reptiles of Azerbaijan