|Male during land phase|
The smooth newt, northern smooth newt or common newt (Lissotriton vulgaris) is a species of newt. It is widespread in much of Eurasia, from the British Isles to Siberia and northern Kazakhstan, and introduced to Australia. Individuals are brown with an orange to white, spotted underside and reach a length of 8–11 cm (3.1–4.3 in), with males being larger than females. The skin is dry and velvety while the newts live on land but become smooth when they migrate into water for breeding. Breeding males develop a more vivid colour pattern and a conspicuous skin seam (crest) on their back.
Originally described by Carl Linnaeus as a lizard, the smooth newt went by different genus names before the current classification in Lissotriton was adopted. Three subspecies are currently accepted. Four former subspecies, all with more restricted ranges, are now classified as separate species, as they are distinct in appearance and genetically: the Caucasian, the Greek, Kosswig's and Schmidtler's smooth newt. The smooth newt forms a species complex with these four species and the Carpathian newt and hybridises with some of them.
Smooth newts live on land for most of the year, where they are mostly nocturnal and hide during the day. They can adapt to a wide range of natural or semi-natural habitats, from forests over field edges to parks and gardens. The newts feed mainly on various invertebrates such as insects or earthworms and are themselves eaten by predators such as fish, birds or snakes. Between spring and summer, they breed in ponds or similar water bodies. Males court females with a ritualised underwater display. Females then lay their eggs on water plants, and larvae hatch after 10 to 20 days. They develop over around three months before metamorphosing into terrestrial juveniles (efts). Maturity is reached after two to three years, and adults can reach an age of up to 14 years.
The smooth newt is common over much of its range and classified as Least Concern species by the IUCN. It is however negatively affected by habitat destruction and fragmentation and the introduction of fish. Like other European amphibians, it is listed in the Berne Convention as a protected species.
Swedish naturalist Carl Linnaeus described the smooth newt in 1758 as Lacerta vulgaris, placing it in the same genus as the green lizards. 370 It was later re-described under several different species and genus names, including Triton , Molge , Salamandra and Lissotriton , with in total 48 species synonyms published. Most recently, it was included in the genus Triturus , along with most European newts. :221 This genus however was found to be polyphyletic, containing several unrelated lineages, and the small-bodied newts, including the smooth newt, were therefore split off as separate genus in 2004 by García-París and colleagues. :233 They used the name Lissotriton, introduced by the English zoologist Thomas Bell in 1839 with the smooth newt as type species :132 but then considered a synonym of Triturus. "Lissotriton" is a combination of Greek λισσός , lissós for "smooth" and the name of Triton, an ancient Greek god of the sea, while the species epithet vulgaris means "common" in Latin. :17:
Three subspecies are accepted by Pabijan, Wielstra and colleagues: L. v. vulgaris, L. v. ampelensis and L. v. meridionalis.These authors, followed by Amphibian Species of the World, recognise four former subspecies from southern Europe and west Asia as separate species, as they are morphologically and genetically distinct: the Greek smooth newt (L. graecus), Kosswig's smooth newt (L. kosswigi), the Caucasian smooth newt (L. lantzi) and Schmidtler's smooth newt (L. schmidtleri). The five smooth newt species and the Carpathian newt (L. montadoni), which is their sister species, have collectively been referred to as the "smooth newt species complex".
To distinguish the smooth newt from its close relatives, the English name "northern smooth newt" has been suggested.Other common names that have been used in the literature include: common newt, great water-newt, common water-newt, warty eft, water eft, common smooth newt, small newt, small eft, small evet, and brown eft.
Molecular phylogenetic analyses have shown that the smooth newt is distinct from its four close relatives – the Caucasian, Greek, Kosswig's, and Schmidtler's smooth newt – which were formerly considered subspecies (see section Taxonomy above). The relationships within this species complex have however not been fully resolved. Within the smooth newt itself, genetic groups do not completely match the currently accepted subspecies (ampelensis, meridionalis, vulgaris), described based on morphology.The five smooth newt species collectively were estimated to have diverged from the Carpathian newt around four to six million years ago.
Genetic analyses have also demonstrated ongoing gene flow between the smooth newt and its relatives. Although the Carpathian newt is morphologically clearly different, hybridisation between the two species is frequent; 26 it has been shown that smooth newt mitochondrial DNA has introgressed into and completely replaced that of the Carpathian newt populations. Partial introgression also occurred from the smooth newt to the Greek smooth newt. These patterns are likely due to the range expansion and secondary contact of species after the Last Glacial Maximum, which they likely survived in refugia mainly in southern and eastern Europe. The palmate newt (Lissotriton helveticus), although often occurring in the same habitats, almost never hybridises with the smooth newt. :25 Artificial crosses with even more distant species such as the alpine (Ichthyosaura alpestris) and northern crested (Triturus cristatus) newts were however successful in laboratory experiments. :29:
Adult males of the smooth newt reach around 9–11 cm (3.5–4.3 in) head-to-tail length and are thus slightly larger than the females, which reach 8–9.5 cm (3.1–3.7 in). The body weight of adults varies between 0.3 and 5.2 g, and decreases during the breeding season. The head is longer than it is wide, with 2–3 longitudinal grooves on the top, and the elongated snout is blunt in the male and rounded in the female. The skin is velvety and water-repellent on land but smooth during the aquatic phase; it contains mucus and toxin glands and its upper layer is shed off regularly. :80–93 :233–234
Outside the breeding season, both sexes are yellow-brown, brown or olive-brown. The male has dark, round spots, while the female has smaller spots of the same colour, which sometimes form two or more irregular lines along the back. The male has an orange strip on the tail underside, and the throat and belly in males are orange to white with small dark, rounded spots (these are lighter with smaller spots in the female). Size and colour vary with environment, and the newts tend to be smaller in northern latitudes. 80–93 :233–234 Albinistic and leucistic individuals have been described. :94:
The smooth newt is diploid (i.e. it has two copies of each chromosome), with 24 chromosomes in total. 107:
During the aquatic breeding season, males develop a skin seam or crest, which runs uninterrupted along the back and the tail. It is 1–1.5 mm high at mid-body, but higher along the tail. The tail also has a lower fin, and its end is pointed. The cloaca (the single digestive, urinary and reproductive orifice) of breeding males is swollen, round and dark-coloured. The hindfeet have more or less developed toe flaps, depending on the subspecies. Colours in general are more vivid than during the land phase. The dark spots grow larger, and the crest often has vertical dark and bright bands. There are five to seven longitudinal stripes on the head. The lower edge of the tail is red with a silver-blue flash and black spots. Females only develop low, straight tail fins but no crest or toe flaps, and are more drably coloured. :26 :233–234
Subspecies differ slightly in male secondary characteristics: L. v. ampelensis has strongly developed toe flaps, its tail tapers into a fine thread (but not a distinct filament), and the body is slightly square in cross-section. L. v. meridionalis also has toe flaps and a pointed tail, its crest is smooth-edged, and its body is square-shaped. In the nominate subspecies, L. v. vulgaris, the crest is clearly denticulated, toe flaps are only weakly developed and the body is round. 234–236:
The aquatic larvae are 6.5–7 mm long and yellow-brown with two longitudinal stripes at hatching. They initially have, in addition to their gills, only two balancers at the sides of the head, short appendages for attaching to plants which get resorbed within a few days. :237 As in all salamanders, forelegs develop before the hindlegs. The colour becomes a more cryptic, darkly marbled yellow to brown in the growing larvae. Larvae are very slender and similar to the palmate newt. They develop a skin seam from the neck to the pointed tail; the tail is as long as the head and trunk. The larvae grow to 3–4.5 cm (1.2–1.8 in), which is also the size of the efts (the terrestrial juveniles) just after metamorphosis. :188–192
The smooth newt resembles the other, less widespread Lissotriton species. It can be confused especially with the closely related "smooth newt complex" species (marked with * in the table below) and the more distant palmate newt, which often occurs in the same area. 25 Females are especially difficult to tell apart, as distinguishing features are mainly observed in the males at breeding season. :19–41 :225–235:
|Species||Distribution||Breeding male characteristics||Other|
|Body shape||Dorsal crest||Toe flaps (hind feet)||Tail end|
|widespread from British Isles to Central Asia||round to square (depending on subspecies)||smooth or denticulated (depending on subspecies)||weakly to well developed (depending on subspecies)||pointed to elongated, no filament|
| Bosca's newt |
|West Iberian peninsula||slightly square||none||none||short filament||belly with some dark spots, especially at sides|
| Carpathian newt* |
|Carpathians||square||very low, smooth-edged||weakly developed||blunt, with filament||belly unspotted|
| Caucasian smooth newt* |
|Caucasus||slightly square||high (>1 mm at mid-body), denticulated (almost spine-shaped)||moderately developed||pointed, but no filament|
| Greek smooth newt* |
|Southern Balkans||square||low (<1 mm at mid-body), smooth-edged||well developed||long filament||lower tail fin unspotted|
| Italian newt |
|Southern Italy||slightly square||none||none||pointed, no filament||very small, 4.5–7.5 cm (1.8–3.0 in); throat with few or no spots; golden-yellow patch behind eyes in both sexes|
| Kosswig's smooth newt* |
|Northern Anatolia||square||low (<1 mm at mid-body) but higher at tail base||strongly developed||long filament|
| Palmate newt |
|Western Europe||square||low, smooth-edged||strongly developed||long filament (both sexes)||throat unspotted|
| Schmidtler's smooth newt* |
|Anatolia and eastern Balkans||slightly square||high (>2 mm at mid-body), denticulated||weakly developed||elongated, no filament||very small, 5–7 cm (2.0–2.8 in)|
The smooth newt has been described as "the most ubiquitous and widely distributed newt of the Old World". 237 The nominate subspecies, L. v. vulgaris, is most widespread and ranges natively from Ireland (where the smooth newt is the only newt species :42) and Great Britain in the west to Siberia and northern Kazakhstan in the east. In the north it reaches central Fennoscandia, and its southern limit is central France, northern Italy, the central Balkans and the dry Eurasian steppe of Ukraine and Russia. :234–238 :42–44 The subspecies L. v. ampelensis only occurs in the Carpathians of Ukraine and the Danube delta of northern Romania, and L. v. meridionalis in the northern half of Italy, southern Switzerland, Slovenia and Croatia. :234–235:
In the Carpathians, the smooth newt generally prefers lower elevations than the Carpathian newt. In the Balkans, the precise contact zones with the Greek smooth newt and Schmidtler's smooth newt are not yet clear.In central Italy, where the range of the smooth newt subspecies L. v. meridionalis overlaps with that of the Italian newt (L. italicus), it was found that the latter prefers a warmer and drier climate.
The nominate subspecies, L. v. vulgaris, has been introduced to Australia, which has no native salamander species. The smooth newt was available in the Australian pet trade until 1997, when it was declared a "controlled pest animal" because of the risk of introduction. The first record in the wild was made near Melbourne in 2011, and larvae were later found, indicating successful reproduction. Negative impacts on the native fauna are feared, including predation on and competition with native frogs and freshwater invertebrates, toxicity, and disease spread. The smooth newt could spread further in south-eastern Australia, where wide areas have a suitable climate.
Within Europe, the subspecies L. v. meridionalis was introduced north of the Alps near Geneva, where it hybridises with the native L. v. vulgaris.
Mainly a lowland species, the smooth newt is only exceptionally found above 1,000 m (3,300 ft). :78–80 It accepts a wide range of terrestrial and aquatic habitats. On land, it occurs in wooded areas (dense conifer woods are avoided) but also in more open areas such as damp meadows, field edges, parks and gardens. It readily adapts to urban environments. The newts hide under structures such as logs or stones or in small mammal burrows. :120–134 :238
Freshwater breeding sites must be close to the land habitats. They are typically sun-exposed, free from fish, stagnant, water-filled permanently or for at least three months of the year, close to similar water bodies, and have shallow areas with abundant water plants. They can range from small puddles to larger ponds or shallow parts of lakes. Water quality is less important; pH values from 4 (more acidic) to 9.6 (more alkaline) are tolerated and in Germany, smooth newts have even been found in slightly brackish water. 121–129 They often share breeding sites with other amphibians, including other newts; in northern France, ponds with five newt species – smooth, palmate, alpine, northern crested and marbled (T. marmoratus) newt – have been described. :151–152:
Smooth newts live on land during most of the year and are mainly nocturnal. They also usually hibernate on land, often in congregations of several newts in winter shelters such as under logs or in burrows (but they can be active during mild weather 238 The newts recognise familiar territory using smell and visual cues, but could not orient themselves in experiments when they were transported far away from the home range.). The efts turn into mature adults at two to three years, and the newts can reach an age of 6–14 years in the wild. :
|The life cycle of the newt , British Council, 1942. Educational film on the smooth newt (10:08 min).|
Migration to the breeding sites occurs as soon as February, but in the northern parts of the range and at higher altitudes, it may not start before summer. After entering the water, the breeding characters, especially the male's crest, take a few weeks to develop. 238:
Mating involves an intricate courtship display: The male attempts to attract a female by swimming in front of her and sniffing her cloaca. He then vibrates his tail against his body, sometimes violently lashing it, thereby fanning pheromones towards her. In the final phase, he moves away from her, the tail quivering. If she is still interested, she will follow him and touch his cloaca with her snout, whereupon he deposits a packet of sperm (a spermatophore). He then guides her over the spermatophore so she picks it up with her cloaca. Males often try to lead females away from displaying competitors. 238–240:
Eggs are fertilised internally, and progeny of one female usually has multiple fathers. Females tend to mate preferentially with unrelated males, probably to avoid inbreeding depression.
Females lay 100–500 eggs, usually folding them into waterplants. The eggs are 1.3–1.7 mm in diameter (2.7–4 mm with jelly capsule) and light brown to greenish or grey in colour. Larvae typically hatch after 10–20 days, depending on temperature, and metamorphose into terrestrial efts after around three months. :238–240
Paedomorphism, where adults stay aquatic and retain their gills and skin seams or only resorb them partially, occurs regularly but only in a small proportion of individuals. It does not appear to be determined genetically but favoured by cold water, a low density of individuals and abundant aquatic prey. Wild paedomorphic individuals often metamorphosed when they were transferred into an aquarium. 192–193:
Smooth newts, including the larvae, are unselective carnivores, feeding mainly on diverse invertebrates such as earthworms, snails or insects, or smaller plankton. Cannibalism also occurs, mainly by preying on eggs of its own species. Various predators eat smooth newts, including waterbirds, snakes and frogs, but also larger newts such as the northern crested newt. 238:
Various pathogens and parasites have been found to infect smooth newts, including ranaviruses, 164 trematodes :164 (of which Parastrigea robusta was found to cause the local decline of a population in Germany ) and at least 31 species of helminths.a picornavirus, various protozoans, :
The smooth newt is common over much of its range. 237 The IUCN, in 2008, assessed its threat status as Least Concern and found no general decline in populations. This assessment included subspecies now recognised as separate species (see section Taxonomy above) and needs updating. Despite the overall low concern, the smooth newt is listed in some national red lists, e.g. in Switzerland, the Czech Republic, and the Netherlands. :196 Like all amphibians, it is also listed as protected species in the Berne Convention (Appendix III). Disturbance, capture, killing and trade are prohibited in Ireland under the Wildlife Act 1976, and trade in the UK under the Wildlife and Countryside Act 1981.:
Threats to smooth newts are similar to those affecting other amphibians. They include especially the loss of breeding ponds through destruction or introduction of fish, and the fragmentation of population through roads. 196–197 Secondary habitats can help sustain the species, e.g. former gravel pits or quarries left open. :204–205 The value of artificial water bodies as habitat can be improved when nearby hiding structures like stones or wood are added on land. Garden ponds are readily colonised if they are sun-exposed, have abundant water plants, no fish, and nearby hiding structures. :206–218 Artificial hibernation sites ("newt hotels") were readily used in a study in Norway, especially by juveniles.:
To mark and track individuals and monitor populations, researchers have often amputated phalanges of fingers and toes but these re-grow quickly; a safer and less harmful alternative is recording the individual belly patterns through photography. 223–224 Researchers have also developed genetic methods based on microsatellite distribution to assess patterns of genetic diversity.:
Smooth newts can be kept in captivity, but must come from a legal source under the applicable legislation given their protected status (see above). They need a land and water phase, with hibernation for two to three months at 5–10 °C. :210–215 The juveniles remain terrestrial and will only return to water at maturity. Individuals have reached ages of 4–8, exceptionally up to 20 years, in captivity. :240
Salamanders are a group of amphibians typically characterized by a lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All 10 present-day salamander families are grouped together under the order Urodela. Salamander diversity is highest in the Northern Hemisphere and most species are found in the Holarctic realm, with some species present in the Neotropical realm.
The palmate newt is a species of newt found in Western Europe, from Great Britain to the northern Iberian peninsula. It is 5–9.5 cm (2.0–3.7 in) long and olive or brown with some dark spots. The underside is yellow to orange, and the throat, unlike in the similar smooth newt, always unspotted. A dark stripe runs along the head and through the eyes. Breeding males develop a distinct filament on the end of their tail, strongly webbed hind feet, and a low, smooth crest on their back.
Salamandridae is a family of salamanders consisting of true salamanders and newts. Salamandrids are distinguished from other salamanders by the lack of rib or costal grooves along the sides of their bodies and by their rough skin. Their skin is very granular because of the number of poison glands. They also lack nasolabial grooves. Most species of Salamandridae have moveable eyelids but lack lacrimal glands.
The northern crested newt, great crested newt or warty newt is a newt species native to Great Britain, northern and central continental Europe and parts of Western Siberia. It is a large newt, with females growing up to 16 cm (6.3 in) long. Its back and sides are dark brown, while the belly is yellow to orange with dark blotches. Males develop a conspicuous jagged crest on their back and tail during the breeding season.
The eastern newt is a common newt of eastern North America. It frequents small lakes, ponds, and streams or nearby wet forests. The eastern newt produces tetrodotoxin, which makes the species unpalatable to predatory fish and crayfish. It has a lifespan of 12 to 15 years in the wild, and it may grow to 5 in (13 cm) in length. These animals are common aquarium pets, being either collected from the wild or sold commercially. The striking bright orange juvenile stage, which is land-dwelling, is known as a red eft. Some sources blend the general name of the species and that of the red-spotted newt subspecies into the eastern red-spotted newt.
The alpine newt is a species of newt native to continental Europe and introduced to Great Britain and New Zealand. Adults measure 7–12 cm (2.8–4.7 in) and are usually dark grey to blue on the back and sides, with an orange belly and throat. Males are more conspicuously coloured than the drab females, especially during breeding season.
Triturus is a genus of newts comprising the crested and the marbled newts, which are found from Great Britain through most of continental Europe to westernmost Siberia, Anatolia, and the Caspian Sea region. Their English names refer to their appearance: marbled newts have a green–black colour pattern, while the males of crested newts, which are dark brown with a yellow or orange underside, develop a conspicuous jagged seam on their back and tail during their breeding phase.
Boscá's newt, also known as the Iberian newt, is a species of newt in the family Salamandridae. The species is found in Portugal and western Spain.
The Danube crested newt or Danube newt is a species of newt found in central and eastern Europe, along the basin of the Danube river and some of its tributaries and in the Dnieper delta. It has a smaller and more slender body than the other crested newts in genus Triturus but like these, males develop a conspicuous jagged seam on back and tail during breeding season.
The Carpathian newt, or Montadon's newt, is a species of salamander in the family Salamandridae found in Czech Republic, Poland, Romania, Slovakia, and Ukraine.
The southern marbled newt or pygmy marbled newt is a species of salamander in the family Salamandridae. It is found in Portugal and Spain. Its natural habitats are temperate forests, Mediterranean-type shrubby vegetation, rivers, intermittent rivers, freshwater marshes, intermittent freshwater marshes, arable land, pastureland, rural gardens, water storage areas, ponds, open excavations, irrigated land, canals and ditches. It is threatened by habitat loss.
A newt is a salamander in the subfamily Pleurodelinae. The terrestrial juvenile phase is called an eft. Unlike other members of the family Salamandridae, newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aquatic salamanders are considered newts, however. More than 100 known species of newts are found in North America, Europe, North Africa and Asia. Newts metamorphose through three distinct developmental life stages: aquatic larva, terrestrial juvenile (eft), and adult. Adult newts have lizard-like bodies and return to the water every year to breed, otherwise living in humid, cover-rich land habitats.
Lissotriton is a genus of newts native to Europe and parts of Asia Minor. As most other newts, they are aquatic as larvae and during breeding time but live in terrestrial, humid habitats over the rest of the season.
The Balkan crested newt or Buresch's crested newt is a newt species of the crested newt species complex in genus Triturus, found in Southeastern Europe and Anatolia.
The Anatolian crested newt is a newt species endemic to northern Anatolia in Turkey. Before its description in 2016, it was first considered to belong to the southern crested newt and then the Balkan crested newt. The three species form a complex of morphologically indistinguishable cryptic species. Genetic data demonstrated the Anatolian crested newt to be distinct from the other two species, although it hybridises with the Balkan crested newt at its western range end.
The Greek smooth newt or Greek newt is a newt species found in the southern Balkans, from southern Croatia (Dalmatia) over Montenegro, Albania and North Macedonia to Greece and south-westernmost Bulgaria.
Kosswig's smooth newt is a newt species found in northwestern Anatolia, east of the Bosphorus.
Schmidtler's smooth newt is a newt species found from northwestern Greece and southeast Bulgaria over East Thrace across the Bosphorus to northwest Anatolia. Its range borders that of the smooth newt, the Greek smooth newt and Kosswig's smooth newt to the north, west, and east, respectively.
The Caucasian smooth newt or Caucasian newt is a newt species found in the Caucasus region, from the Don river mouth in Russia to Georgia, and potentially Armenia, Azerbaijan and extreme northeastern Turkey. It occurs from sea level to 2,500 m (8,200 ft) elevation.