Newts презентация

Newt

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, 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.
Newts are threatened by habitat loss, fragmentation and pollution. Several species are endangered, and at least one species, the Yunnan lake newt, has become extinct recently.
Newts are found in North America, Europe, North Africa and Asia. The Pacific newts and the Eastern newts with together seven species are the only representatives in North America, while most diversity is found in the Old World: In Europe and the Middle East, the group's likely origin, eight genera with roughly 30 species are found, with the ribbed newts extending to northernmost Africa. Eastern Asia, from Eastern India over Indochina to Japan, is home to five genera with more than 40 species. Newts are semiaquatic, spending part of the year in the water for reproduction and the rest of the year on land. While most species prefer stagnant water bodies such as ponds, ditches or flooded meadows for reproduction, some species such as the Danube crested newt can also occur in slow-flowing rivers.

The European brook newts and European mountain newts have even adapted to life in cold, oxygen-rich mountain streams. During their terrestrial phase, newts live in humid habitats with abundant cover such as logs, rocks, or earth holes.
Newts share many of the characteristics of their salamander kin, Caudata, including semipermeable glandular skin, four equal-sized limbs, and a distinct tail. The newt's skin, however, is not as smooth as that of other salamanders. The cells at the site of an injury have the ability to undifferentiate, reproduce rapidly, and differentiate again to create a new limb or organ. One hypothesis is that the undifferentiated cells are related to tumor cells, since chemicals that produce tumors in other animals will produce additional limbs in newts.
The main breeding season for newts (in the Northern Hemisphere) is in June and July. After courtship rituals of varying complexity, which take place in ponds or slow-moving streams, the male newt transfers a spermatophore, which is taken up by the female. Fertilized eggs are laid singly and are usually attached to aquatic plants. This distinguishes them from the free-floating eggs of frogs or toads, which are laid in clumps or in strings. Plant leaves are usually folded over and attached to the eggs to protect them. The larvae, which resemble fish fry but are distinguished by their feathery external gills, hatch out in about three weeks. After hatching, they eat algae, small invertebrates, or other amphibian larvae.

European brook newt

The European brook newts, is a genus of newts native to the Pyrenees and central Catalonia. These amphibians were formerly placed within genus Euproctus, but the genus was resurrected in 2005. Instead of Euproctus, they seem more closely related to Triturus, their sister taxon.
Newts are estimated to have split approximately 8 myr ago. This may have been associated with adaptation to fast-running, well-oxygenated mountain streams, leading to some superficial similarity with Euproctus in convergent evolution: strongly depressed head and body, and reduction or even absence of lungs.
They are small- to medium-sized newts, 70–167 mm in total length. Skin is covered with tubercles bearing horny tips, more so above than beneath, which can be completely smooth. Limbs are moderate, with four fingers and five toes. Body is rounded or slightly depressed. There is no cutaneous dorsal and caudal crest, not even during the breeding season. Tail is about as long as head and body and compressed from side; longer in females and deeper in males. Lungs are absent or very reduced. Its natural habitats are oligotrophic, cold (under 15 °C) fast running rivers; it seems to be a strictly aquatic species. Its population is supposed to be less than 1,500 individuals with an estimated rate of decline of 15% during the last 10 years. The drying out of mountain streams, human alteration of its original habitat and the global warming are threats to this species. Because of this, the International Union for Conservation of Nature (IUCN) lists it as "critically endangered".

Fire belly newt

The fire belly newt is a species of newt in the family Salamandridae endemic to Japan and China. The fire belly newts are likely to be the more commonly collected newt instead. It is extremely toxic - fatal within 6 hours - to humans and other animals.
This newt is usually 9–14 cm in length, and can be distinguished from its Chinese relative by its larger size, rough and pebbly skin, and distinct parotoid glands. They are typically brown to black above, often with red specks or spots, and orange to crimson below, usually with a blotched, darker pattern. Males can be distinguished from females by their swollen cloacae, and male newts of this species will often assume a blue iridescent sheen and smoother skin during the breeding season.
In the wild, this species lives on the islands, in clear, cool bodies of water, usually ponds, ditches, pools, or lakes. Reportedly, six subspecies are found through the Japanese islands, each race originating from the region of Japan after which they are named.
These newts are poisonous in the wild, but animals bred in captivity may lose their toxicity. The skin of the wild animals contains tetrodotoxin, which is one of the most effective known nonpeptide toxins. It is a neurotoxin with no known antidote, and can cause death by suffocation in as quickly as six hours after ingestion. The toxin could be formed by environmental bacteria, so could be the reason why some newts in captivity have a lower toxicity than their wild counterparts.

Anderson's crocodile newt

Anderson's crocodile newt, Anderson's newt, Ryukyu spiny newt, or Japanese warty newt is a species of salamander in the family Salamandridae found in the Ryukyu Islands of Japan, and, at least formerly, Mount Guanyin in northern Taiwan, where it is now believed to be extinct.
It is a stout, flat salamander. Head is broad and triangular in shape. There are 12–15 conspicuous knob-like lateral glands. Colouration is uniformly dark brown or black, only the underside of the tail, cloacal region, and the soles of the feet are yellow-orange. The maximum size is at least 80 mm in snout–vent length and 169 mm in total length.
Its natural habitats are broad-leaved evergreen forests, secondary forests, grasslands and swamps. It has also been found in and near sugar cane fields. It breeds in standing water such as ponds and temporary pools; outside breeding season it is difficult to observe as adult salamanders live in leaf litter, in rocky crevices, and under rocks and logs.
The newt is uncommon, and it is threatened by habitat loss and by collection for illegal pet trade.

Smooth newt

The smooth newt, northern smooth newt or common newt 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, 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. Maturity is reached after two to three years, and adults can reach an age of up to 14 years.
Adult males of the smooth newt reach around 9–11 cm head-to-tail length and are thus slightly larger than the females, which reach 8–9.5 cm. 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.
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.

Emperor spotted newt

The Luristan newt, Kaiser's mountain newt, Kaiser's spotted newt or emperor spotted newt, is a species of very colourful salamander in the family Salamandridae. It is endemic to the southern Zagros Mountains in Iran where it is known from just four streams. Populations of this newt have been declining and the International Union for Conservation of Nature has rated it as "vulnerable". A captive breeding programme has been established in several zoos.
The Luristan newt is endemic to the southern Zagros Mountains in Iran. It is primarily found in highland streams surrounded by arid scrubland, but can also be found in ponds and pools. It is known only from four streams in a single catchment area and has a total inhabited area of 8,948 km2. In a recent study it was found that the area of suitable habitat within their study area was 18,159 km2. Water is absent from its habitat for a significant part of the year and it moves out into the surrounding woodland which is predominantly oak and pistachio, during which time this species is known to estivate.
Currently the Lusristan newt if found in the Zagros Mountains in Iran, but in recent studies it has been concluded that small portions of southern Iran that include Kermanshah, Ilam, Chaharmahal-Bakhtiari, and Kohgiluye-Boyerahmad are habitats that these species will be distributing themselves in the future due do climate change affecting their current habitats.

Northern crested newt

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 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 northern crested newt spends most of the year on land, mainly in forested areas in lowlands. It moves to aquatic breeding sites, mainly larger fish-free ponds, in spring. Males court females with a ritualised display and deposit a spermatophore on the ground, which the female then picks up with her cloaca. After fertilisation, a female lays around 200 eggs, folding them into water plants. The larvae develop over two to four months before metamorphosing into terrestrial juveniles. Both larvae and land-dwelling newts mainly feed on different invertebrates.
Several of the northern crested newt's former subspecies are now recognised as separate species in the genus Triturus. Its closest relative is the Danube crested newt. It sometimes forms hybrids with some of its relatives, including the marbled newt. Although today the most widespread Triturus species, the northern crested newt was probably confined to small refugial areas in the Carpathians during the Last Glacial Maximum.

The northern crested newt is a relatively large newt species. Males usually reach 13.5 cm total length, while females grow up to 16 cm. Rare individuals of 20 cm have been recorded. Other crested newt species are more stockily built; only the Danube crested newt is more slender. Body shape is correlated with skeletal build: The northern crested newt has 15 rib-bearing vertebrae, only the Danube crested newt has more, while the other, more stocky Triturus species have 14 or less.
The newts have rough skin, and are dark brown on the back and sides, with black spots and heavy white stippling on the flanks. The female has a yellow line running along the lower tail edge. The throat is mixed yellow–black with fine white stippling, the belly yellow to orange with dark, irregular blotches.
During the aquatic breeding season, males develop crest up to 1.5 cm high, which runs along the back and tail but is interrupted at the tail base. It is heavily indented on the back but smoother on the tail. Also during breeding season, the male's cloaca swells and it has a blue–white flash running along the sides of the tail. Females do not develop a crest.

Black-spotted newt

The black-spotted newt or Texas newt, is a species of aquatic newt native to northeastern Mexico and southern Texas in the United States.
The black-spotted newt grow to 7.4–10.9 centimetres long, and is typically an olive green in color, with numerous black spots. The underside is often yellow in color, which can sometimes extend up to the sides. They have smooth skin, and a paddle-shaped, vertically flattened tail. They live in quiet stretches of streams and permanent and temporary ponds and ditches.
Black-spotted newts prefer shallow-water habitats, heavy with vegetation. During the dry season, they are believed to burrow underground or remain under debris. They are carnivorous, consuming a wide variety of prey, including insects, aquatic invertebrates, leeches, and other amphibians. Their toxic skin secretions are used to deter predators. Breeding occurs year-round. The life history of this species is not well known and the presence of an stage has yet to be determined.

California newt

The California newt or orange-bellied newt, is a species of newt endemic to California, in the Western United States. Its adult length can range from 5 to 8 in. Its skin produces a potent toxin.
California newts reside in the coastal counties of California and in the southern Sierra Nevada and occupy a diverse array of habitats found near the small ponds and creeks where they breed, including woodlands and chaparral. Newts are amphibians. They are salamanders in the subfamily called Pleurodelinae.
The California newt has warty, slate-gray skin on its back and bright orange-yellow skin underneath. It is very similar in appearance to the rough-skinned newt and they are often indistinguishable without dissection, but in general, the California newt has orange skin around the bottom of its eye while the Rough-skinned has gray skin at the bottom of its eye. The California newt also has eyes that protrude beyond the edge of the jaw line when viewed from above, while the eyes of the rough-skinned do not protrude, giving its head a more bullet-like appearance. The red-bellied newt is also similar but has dark irises vs. yellow in the California newt, more red coloration underneath, and a dark band across the vent that is lacking in the California newt. Newts are amphibians. They are related to salamanders (in a subfamily called Pleurodelinae). They live in North America, Europe and Asia. Their skin tends to be rougher than the skin of salamanders.

Marbled newt

The marbled newt is a mainly terrestrial newt native to the Iberian Peninsula and France in Europe.
Marbled newts have dark brown or black bodies with irregular patterns of green. They have black bellies with off-white specks. Adult females have an orange stripe running down the back from the head to the tip of the tail. Juveniles also have this stripe, but it fades on males at about 9 months. Breeding males have a large wavy crest that runs from its neck down to the tip of its tail, but is a little bit shorter where the tail meets the body. The crest is striped yellowish-white with black. Adult marbled newts are from 5 inches to 6.5 inches long.
Marbled newts live throughout most of France, and northern Spain west to the northern third of Portugal. They have a slight overlap with the pygmy marbled newt, which take over southern Spain. Marbled newts are absent from most of the Pyrenees because of dry and unstable conditions. In northern France, the populations are more scattered due to the presence of the great crested newt, with which the marbled newt hybridizes to some extent. The higher-elevation Mediterranean climates are the preferred habitat of marbled newts, and in the overlap, it takes the lower elevations.

Red-tailed knobby newt