| Marbled newt | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | Urodela |
| Family: | Salamandridae |
| Genus: | Triturus |
| Species: | T. marmoratus |
| Binomial name | |
| Triturus marmoratus (Latreille, 1800) | |
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| Distribution of the marbled newt in Western Europe | |
The marbled newt (Triturus marmoratus) is a mainly terrestrial newt native to western Europe. They are found in the Iberian Peninsula and France, where they typically inhabit mountainous areas.
The marbled newt is typically found in habitats characterized by hilly and forestry terrain, away from open and exposed areas. [2] Marbled newts live in temporary habitats, such as ponds, that are subject to change depending on the climate conditions of the region. When rainfall is high and the temperature is lower, typically in the fall and winter months, adult marbled newts stay in the ponds. However, these shallow ponds are subject to drought in warmer spring and summer months, which forces the marbled newts to remain on land. Due to this constant change in the habitat conditions, marbled newts have the ability to adapt to different climatic conditions and habitat changes. [3]
The characteristics of the marbled newt's habitat have also been found to affect the maturity of both males and females. Newts found in Mediterranean regions have been found to mature earlier than those in regions of France and Portugal. Due to the harsher conditions associated with the climate in Mediterranean regions, marbled newts experience a higher rate of adult mortality; therefore, maturing earlier is advantageous. [3]
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 the stripe fades on males at about 9 months. [4] 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 range from 5 inches (13 cm) to 6.5 inches (17 cm) long. [4]
Both males and females follow similar directions for pre- and post-breeding migrations. Migration occurring in the spring is also significantly different from winter. Migration also puts the newts at increased risk of predation due to exposition to a larger group of predators. Desiccation as a result of migration is also a concern. [5] Marbled newts typically migrate a short distance initially, covering a distance of about 10 meters. However, the newts have been shown to migrate up to 160 meters away from their initial habitat. Migration routes filled with trees and bushes are preferred because they allow for adequate shelter, minimizing the amount of open area that the newt could be exposed to. The newts can also migrate through open areas if underground refuges are available as coverage. [2]
Differences in environmental conditions are responsible for changes in bone density and formation for marbled newts living in different areas. The marbled newts, like some other amphibians, experience a phase of growth in the spring and summer. This is then followed by growth arrest in the winter. Observing the changes in growth is an important benchmark to have in marbled newts, as climate change is significantly impacting their typical environmental conditions. The breeding season for the newts begins in February and larvae hatch in late March. The metamorphosis phase is from April until the end of June, with new juveniles leaving at the end of June at the latest. During the most intense part of the summer (July-September), breeding ponds dry up. This causes a significant decrease in activity, which increases again only when rainfall began again in August. [3]
The marbled newt locates breeding ponds primarily through celestial cues. It was found that when these cues are unavailable, they do not migrate. When tested under clear and overcast sky conditions, the newts were not able to orient themselves accordingly. However, when altering the geomagnetic field of their location, the newts showed no change in orientation, which suggests that an altered geomagnetic field does not affect orientation. Other possibilities for orientation include specific odors of the pond as well as visual landmarks that can serve as cues of correct or incorrect location. [6]
Another form of locating breeding ponds for marbled newts are acoustic cues. It has been found that marbled newts sometimes use the calls of another frog, B. calamita, to locate their breeding ponds. While the ears of newts are not as complex as those of humans, they have inner ears capable of processing sound. Sound can be used to aid in finding breeding ponds, but celestial cues remain essential for successful location of breeding ponds. [7]
Males have shown a preference for larger female newts. This is because larger females show increased efficiency in oviposition in comparison to smaller female newts. Such increased efficiency allows for a decrease in parental investment and energy cost associated with oviposition. [9]
Marbled newts experience a female-biased sexual dimorphism with regards to size. Females are not only significantly larger than males, but also experience a longer life span. This combined with reaching sexual maturity at a younger age in comparison to males are causes for increased female fecundity. Larger females are thought to produce larger offspring, who in turn have more reproductive success. [10] Males have a discernible crest selected for by females. The height of the crest offers an indication of good fitness and physical condition, making mates with a higher crest more desirable by females. [10]
During courtship with females, males perform ‘tail-lashing’ in order to spread their pheromones. This also draws attention to the males and accentuates their long tailfin, another trait also selected for by female choice. Males are able to spread these pheromones because they are equipped with a set of glands that females do not have. This trait directly affects male reproductive success as it is used solely in attracting a mate and offers no other benefits. [10]
Since males do not need to be present for egg deposition, females have full control of oviposition, choosing both location and time. Females prefer to lay their eggs in a different location each time in an attempt to decrease mortality. Each egg is deposited and carefully folded by its hind legs within an aquatic leaf that had been carefully chosen by the female. The female smells and inspects the chosen leaf prior to wrapping it around the egg. [9]
Failures in egg laying can occur. These typically follow or come before the successful deposition of an egg. In some cases, the leaf chosen is too small for deposition or is already occupied by another egg. The eggs are folded within leaves as a way to provide parental care. The time taken to choose and carefully wrap each egg within a leaf is a form of parental investment from the mother as a way to protect the egg. The process of oviposition also interrupts breathing; therefore, the time taken for this process is very important. There are cases in which female marbled newts are forced to halt oviposition in order to take a breath at the surface. It has been found that larger females experience more success in oviposition because they are able to endure longer periods of time without taking a breath relative to smaller females. By the same reasoning, larger females also experience fewer failed attempts at oviposition than their smaller counterparts, allowing them to be more efficient at reproduction. [9]
The marbled newt is listed as near-threatened on the French national red list of species. [11] Conservation planning should take into consideration buffer zones surrounding ponds and the ecological requirements associated with them while the marbled newts are migrating. These wetlands in the buffer zone are important in order to allow the newts to successfully complete their biological cycles. It is important to ensure that there are adequate, good-quality, shelters for marbled newts to use during migration in order to reduce the predation and desiccation risk associated with migration. [5]
Changes in the marbled newt habitat have occurred over the last few years. With the loss of many forest areas, their typical ranges are being diminished along with their population. This loss of habitat is allowing the range and population of another newt, T. cristatus, to expand. This newt species prefers open and flat areas. [2] The largest cause of habitat loss is climate change, with land use cover being the secondary cause. Climate change directly affects the water cycle and temperature—two very important environmental factors for amphibian species. These changes have the ability to directly affect the migration range and general territory of the marbled newts. The range of the newts has been reduced over the past few years and is expected to experience further restrictions over the course of the 21st century. While large-scale experiments have been done to assess the general risk of climate change and direct human impact on the habitat of marbled newts, more local and smaller-scale studies must be performed to determine the full range of effects on these newts. [11]
T. cristaus and T. marmoratus (marbled newts) overlap in some areas in France where their habitat preferences overlap; this allows them to hybridize. [13] T. cristaus has been known to occupy increasingly larger areas due to climate change fragmenting the habitat of the marbled newt. Despite the loss of habitat, the marbled newt has experienced more reproductive success. Females have a longer life-span and thus more years to reproduce. The eggs of both T. cristaus and T. marmoratus suffer the same mortality rates. The hybrids of these two species have even more fecundity than the marbled newts, but their eggs and embryos are less likely to survive. [13]
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typically its form is adapted to functions such as preparing a place for the egg, transmitting the egg, and then placing it properly. For most insects, the organ is used merely to attach the egg to some surface, but for many parasitic species, it is a piercing organ as well.
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 color 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 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.
The ringed salamander is a species of mole salamander native to hardwood and mixed hardwood-pine forested areas in and around the Ozark Plateau and Ouachita Mountains of Arkansas, Oklahoma, and Missouri. This species of salamander has slander body, small head, and long tail. They are usually found to have various dorsal color from dark gray to dark brown. Various close relatives are found such as marbled salamander and spotted salamander. This species of salamander has cannibal behavior especially those in large body size.
The southern crested newt is a terrestrial European newt. It is similar to the northern crested newt except larger and more robust.
The Italian crested newt is a species of newt in the family Salamandridae.
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 Montandon’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.
The southern banded newt is a species of salamander in the family Salamandridae found in Armenia, Iraq, Israel, Jordan, Lebanon, Syria, and Turkey. This species has two subspecies - O. v. vittatus and O. v. ciliensis.
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.
Triturus species | ||
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| Crested newts |
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| Marbled newts |
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