''Natrix maura'' is a natricine water snake of the genus '' Natrix''. Its common name is viperine water snake or viperine snake. Despite its common names, it is not a member of the subfamily

Viperinae The Viperinae, or viperines, are a subfamily of vipers endemic to Europe, Asia and Africa. They are distinguished by their lack of the heat-sensing pit organs that characterize their sister group, the subfamily Crotalinae. Currently, 13 genera ...

. This nonvenomous, semiaquatic, fish-eating snake was given its common names due to behavioural and aesthetic similarities with sympatric adder species.

Behaviour

The viperine snake looks like an adder and behaves like one. It is known to strike like an adder, but not bite. However, when in water, the viperine snake then looks like a grass snake and hunts its

prey Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

in the same way. This snake is diurnal.UIcnmed.org
/ref> Viperine water snakes are not aggressive and rarely bite. They spend most of their time in water hunting fish, frogs and other aquatic animals.

Geographic range

The viperine snake is found in southwestern Europe and northwestern Africa. Specifically, ''N. maura'' is found in the European countries of:

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of th ...

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

, northernwest

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

, and even into

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

. It has spread to areas of

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

, as well. It is found in African countries of

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...

, northern

Algeria ) , image_map = Algeria (centered orthographic projection).svg , map_caption = , image_map2 = , capital = Algiers , coordinates = , largest_city = capital , relig ...

, northwestern

Libya Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to the east, Suda ...

, and northern to central

Tunisia ) , image_map = Tunisia location (orthographic projection).svg , map_caption = Location of Tunisia in northern Africa , image_map2 = , capital = Tunis , largest_city = capital , ...

Description

''N. maura'' is gray, brown, or reddish dorsally, with a black zigzag vertebral stripe, and lateral series of black ocelli with yellow centers. The labials are yellow with black sutures. It has a diagonal dark band on each temple, and another behind it on each side of the neck. Ventrally, it is yellow or red, checkered with black, or all black. The strongly keeled dorsal scales are arranged in 21 rows. The ventrals are 147–160; the anal plate is divided; and the paired subcaudals number 47–72. Adults may attain a total length of 85 cm (33 inches), with a tail 17 cm (7 inches) long. Boulenger GA. 1893. ''Catalogue of the Snakes in the British Museum (Natural History). Volume I., Containing the Families ... Colubridæ Aglyphæ, part.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 448 pp. + Plates I-XXVIII. (''Tropidonotus viperinus'', pp. 235–237).

Habitat

The viperine snake is found in

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of ...

s and

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s, and has also been recorded from areas of brackish water.

Invasion

Invasive on

Mallorca Mallorca, or Majorca, is the largest island in the Balearic Islands, which are part of Spain and located in the Mediterranean. The capital of the island, Palma, is also the capital of the autonomous community of the Balearic Islands. The Bale ...

Ecology of invasion

''N. maura'' predates on ''

Pelophylax perezi The Perez's frog, also known as Iberian waterfrog, Iberian green frog, or Coruna frog (''Pelophylax perezi'') is a species of frog in the family Ranidae. It is native to southern France, Portugal, Spain, and has been introduced to the Canar ...

'' among other prey on Mallorca. Research by Moore et al. 2004 suggests

trophic subsidy Trophic, from Ancient Greek τροφικός (''trophikos'') "pertaining to food or nourishment", may refer to: * Trophic cascade * Trophic coherence * Trophic egg * Trophic function * Trophic hormone * Trophic level index * Trophic level * Troph ...

provided by ''P. perezi'' is maintaining higher numbers of the invader than would otherwise occur.

Evolutionary effects

''N. maura'' has altered the behavior of Mallorcan prey. Moore et al. 2004 finds that the higher numbers mentioned above are allowing the invader to exert such high pressure that prey species have retreated entirely to habitats too steep for ''N. maura''.

References

External links

Euroherp.com