Danube crested newt | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Urodela |
Family: | Salamandridae |
Genus: | Triturus |
Species: | T. dobrogicus |
Binomial name | |
Triturus dobrogicus (Kiritzescu, 1903) | |
Synonyms [2] | |
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The Danube crested newt or Danube newt (Triturus dobrogicus) 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.
For half of the year or longer, adults live in slow-flowing river margins, lakes, or ponds, where reproduction takes place. Males perform a courtship display, and females lay around 200 eggs individually onto leaves of aquatic plants. Larvae develop two to four months in the water before reaching metamorphosis. For the remainder of the year, the newts live in shady land habitats, usually forests. Although not yet considered threatened, Danube crested newt populations have declined significantly, the reason being mainly habitat loss. The species is protected by law in the European Union.
The Danube crested newt was described as a variety of the northern crested newt (Triturus cristatus) by C. Kiritzescu in 1903. [3] Later, it was considered a subspecies until genetic analysis supported its recognition as a separate species in the crested newt species complex. [2] The northern crested newt is its sister species, according to phylogenomic studies. [4] [5]
Separated populations from the Danube Delta and the Pannonian Basin (see section Distribution and habitats) were described as two subspecies, T. dobrogicus dobrogicus and T. dobrogicus macrosoma, in 2000. [6] Later genetic study, however, did not support the distinction of these two forms. [7] [8]
Measuring 13 to 15 centimetres (5.1 to 5.9 in) long in total, sometimes up to 18 centimetres (7.1 in) in females, [9] : 345 the Danube crested newt is the smallest crested newt species. It has a more slender, elongate body than the other species, well adapted to swimming, with a narrow head and relatively short limbs. This body shape has evolved through an increase in the number of rib-bearing vertebrae: there are 16–17 of them in T. dobrogicus, the highest number among the crested newts. [10] : 10–14
The Danube crested newt's back and sides are dark brown with black spots and white stippling. The belly is orange to red (in other crested newts, it is usually yellow or orange–yellow), with small or medium-sized black blotches that have sharp edges. Like all crested newts, T. dobrogicus males develop a crest on their back and tail during breeding phase, which can be quite high and jagged, usually starts between the eyes and nostrils, and is interrupted at the tail base. Another feature of males at breeding season is a bluish-white stripe along the tail. [10] : 10–14 [9] : 345 Females can sometimes have a yellow stripe along the back, similar to the Italian crested newt (T. carnifex). [9] : 345
The Danube crested newt is found in three allopatric areas of distribution from central to eastern Europe:
In addition to the northern crested newt to the north, the Danube crested newt's range borders that of the Italian crested newt (T. carnifex) in the west, and that of the Macedonian (T. macedonicus) and Balkan (T. ivanbureschi) crested newts in the south. [10] : 16–17
Compared to the other crested newt species, the Danube crested newt is more adapted to life along a river system and frequently occurs in flowing water and together with fish. Typical breeding sites are slow-flowing river margins, oxbow lakes, flooded marshland, larger ponds, or ditches, provided abundant underwater vegetation is available. [10] : 44–48 [14] : 144–145 During land phase, the newts live in deciduous forests or groves, bushlands, or meadows. [1]
Danube crested newts have the longest aquatic phase in the genus Triturus. Adults move to their breeding sites in February or March and usually stay there for six months; occasionally, they may even stay longer or return to the water in autumn. [10] : 44 [14] : 144–145 Males court females with a display of ritualised body movements. When they have gained the female's interest, they guide it over a spermatophore they deposit on the ground, which the female then takes up with her cloaca. [10] : 80–89 The eggs are fertilised internally. As in other crested newts, a female lays around 200 eggs per season, which are folded individually into leaves of aquatic plants. Eggs and larvae are smaller than in the other crested newt species, and they take longer (two to four months) until they reach metamorphosis and leave the water. [10] : 61–65 [9] : 345
Both in water and on land, the newts are largely nocturnal. In their aquatic habitats, they hide under vegetation, and on land, they use structures such as logs, rocks, or small animal burrows for cover. [10] : 47–48, 58 They feed mainly on different invertebrates, but in the water may also prey on tadpoles and smaller newts. [10] : 58–59 Predators include herons and other birds, snakes such as the grass snake, and various carnivorous mammals. [10] : 78
The population of the Danube crested newt has declined significantly, and the International Union for Conservation of Nature has assessed its conservation status as "least concern". The main threat is habitat destruction by humans, especially through drainage, damming, or pollution. Hybridisation with other crested newt species and a loss of breeding ponds because of decreasing spring rain in the southern range (possibly due to global warming) are also seen as threats. [1] Like the other crested newts, T. dobrogicus is listed in the Berne Convention (appendix II) and the EU Habitats Directive (annexes II and IV), and capture, disturbance, killing, trade, and destruction of habitats are prohibited. [15] [16]
The smooth newt, European newt, northern smooth newt or common newt is a species of newt. It is widespread in Europe and parts of Asia, and has been introduced into Australia. Individuals are brown with a spotted underside that ranges in colour from orange to white. They reach an average length of 8–11 cm (3.1–4.3 in); males are larger than females. The newts' skins are dry and velvety when they are living on land, but become smooth when they migrate into the water to breed. Males develop a more vivid colour pattern and a conspicuous skin seam (crest) on their back when breeding.
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 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.
The southern crested newt is a terrestrial European newt. It is similar to the northern crested newt except larger and more robust.
The marbled newt is a mainly terrestrial newt native to western Europe. They are found in the Iberian Peninsula and France, where they typically inhabit mountainous areas.
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 Italian crested newt is a species of newt in the family Salamandridae.
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.
Ommatotriton ophryticus, the northern banded newt, is a species of newt in the family Salamandridae. It is found in northeastern Turkey and western Caucasus in Georgia, Armenia, and southern Russia.
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.
Triturus macedonicus, the Macedonian crested newt, is a newt species of the crested newt species complex in genus Triturus, found in the Western Balkan peninsula.
The Anatolian crested newt is a species of newt endemic to northern Anatolia in Turkey. Before its description in 2016, it was initially 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.
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.