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Imagem de Tritão-alpino
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Tritão Alpino

Ichthyosaura alpestris (Laurenti 1768)

Description ( Inglês )

fornecido por AmphibiaWeb articles
Vomerine tooth series in two lines which widely diverge posteriorly and converge anteriorly. Tail length approximately equal to or a little shorter than body with head. Skin smooth in the adults in the aquatic phase and granular in the terrestrial phase. Dorsal surface dark, grayish, brown or olive, and sometimes almost black. Unclear light spots often present, sometimes forming blotched-like pattern; sometimes white spots are present on the flanks. Ventral surface are bright yellow or orange. Terrestrial males have remains of the mid-dorsal crest, and a more swollen cloaca than females. During the breeding season, the male has a low middorsal crest, unnotched, with light and dark spots, and bright blue spots and white or silver longitudinal bands with dark points on the body flanks. The female has no middorsal crest or lateral bands. The blue spots on her dorsal surface may be fused. There are also significant sexual differences in morphometrics of body and tail length (females are slightly larger), the lengths of the foreleg and hindleg, relative head length, etc.The phylogeography of I. alpestris has recently been investigated using mtDNA, revealing five major clades (Sotiropoulos et al. 2007). Clade A consists of populations from southeastern Serbia, with this clade originating in the late Miocene. This Serbian lineage is thought to be ancestral to a western and an eastern lineage, with a mid-Pliocene divergence. The western lineage is divided into Clade B (Italy) and C (central Europe and Iberia). The eastern lineage is divided into Clade D (southern Balkans) and E (central-northern Balkans). Eastern clades seem to have been isolated in multiple refugia during glaciation cycles, based on high sequence divergence. Western clades are thought to have colonized central, western, and northeastern Europe from a possible refugium in central Europe (Sotiropoulos et al. 2007).This analysis also indicates that paedomorphic lineages of I. alpestris appear to have evolved during early to mid-Pleistocene, likely in response to the ongoing climatic fluctuations (Sotiropoulos et al. 2007).At the southernmost edge of the species range, in Greece, two major mitochondrial lineages of I. alpestris veluchiensis have been separated since the mid-Pleistocene. Populations from Peloponnisos and the Greek mainland show significant differences in both nuclear gene frequencies and mitochondrial haplotypes, and consistently fall out into separate, strongly supported clades. These lineages have been proposed to warrant separate conservation status (Sotiropoulos et al. 2007). This species was featured as News of the Week on 3 July 2017:Understanding species thermal niche is critical to predicting how amphibians will respond to climate change. To characterize the thermal niche of European alpine newts (Ichthyosaura alpestris), Gvoždík and Kristin (2017) devised a suite of behavioral and physiological experiments. Using both thermal gradient tracks to calculate preferred temperatures and respirometry trials to monitor aerobic capacity, they tracked food digestion as a measure of thermal performance. Given knowledge of ectotherm physiology one would predict that satiated newts should optimize their aerobic capacity for digestion (i.e., select thermal habitats that maximize their ability to process food). However, the alpine newts in their experiments instead behaved more “economically”, preferring body temperatures that were lower than those required for maximum aerobic capacity. They demonstrate the importance of considering maintenance costs for understanding measures of maximum physiological performance. Here, alpine newts did indeed demonstrate thermoregulatory behavior that maximized their ability to process food, yet they did it relative to the lowest possible energy expense (written by Jeffery Frederick).

Referências

  • Ćirović, R, Radović, D., and Vukov, T. D. (2008). ''Breeding site traits of European newts (Triturus macedonicus, Lissotriton vulgaris, and Mesotriton alpestris in the Montenegrin karst region.'' Archives of Biological Sciences, 60(3), 459-468.
  • Kalezić, M. L., Džukić, G., and Tvrtković, N. (1990). ''Newts (Triturus, Salamandridae, Urodela) of the Bukovica and Ravni Kotari regions.'' Spixiana, 13, 329-338.
  • Schabetsberger, R. and Jersabek, C.D. (1995). ''Alpine Newts (Triturus alpestris) as top predators in a high-altitude karst lake: daily food consumption and impact on the copepod Arctodiaptomus alpinus.'' Freshwater Biology, 33, 47-61.
  • Sotiropoulos, K., Eleftherakosa, K., Džukićb, G., Kalezićb, M. L., Legakisd, A., and Polymenia, R. M. (2007). ''Phylogeny and biogeography of the alpine newt Mesotriton alpestris (Salamandridae, Caudata), inferred from mtDNA sequences.'' Molecular Phylogenetics and Evolution, 45(1), 211-226.
  • Sotiropoulosa, K., Eleftherakosa, K., Kalezićb, M. L., Legakisc, A., and Polymenia, R. M. (2008). ''Genetic structure of the alpine newt, Mesotriton alpestris (Salamandridae, Caudata), in the southern limit of its distribution: Implications for conservation.'' Biochemical Systematics and Ecology, 36(4), 297-311.

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Sergius L. Kuzmin
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Distribution and Habitat ( Inglês )

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The species is distributed in the middle of Europe. The range reaches Denmark as a northern limit and runs southeastward to Romania and Bulgaria via the Carpathians and the Balkan Mountains. The range is fragmented with lowlands, broad valleys, etc., especially in the southern part. A large part of central Europe is inhabited by I. alpestris alpestris; Montenegro is inhabited by I. alpestris serdarus; central Greece by I. alpestris veluchiensis; northern Italy by I. alpestris apuanus; southern Italy by I. alpestris inexpectatus; northern Spain by I. alpestris cyreni. There are seven more populations whose subspecific position was designated by separate names, but was not justified. The species lives usually in mountains up to the alpine belt. It occurs, however, at much lower altitudes. The populations occur usually in the forest and in the areas formerly occupied by forests. This is true especially for lowland populations. In the aquatic phase, it inhabits lakes, ponds, rivulets and swamps with clear stagnant or semi-flowing water. Observations in the Ukrainian Carpathians revealed that the Alpine Newt prefers clearer and cooler waters than the syntopic Carpathian Newt (Lissotriton montandoni). In Montenegro, the Alpine Newt is syntopic with the Smooth Newt (Lissotriton vulgaris) in the Upper Zone of the Montenegrin karst, and is restricted to elevations above 870 m (Ćirović et al. 2008). The Alpine Newt has also been found in other areas of exposed karst within the Balkans but at much lower elevations (e.g. on Mt. Velebit, Croatia, at 80 m) than reported for Montenegro populations (Kalezić et al. 1990).
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Sergius L. Kuzmin
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Life History, Abundance, Activity, and Special Behaviors ( Inglês )

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The Alpine Newt usually is not numerous, but its population density locally reaches 1 specimen per 0.5 m2 in some ponds, usually one specimen per 20-50 m2 at most suitable sites. In the Ukrainian Carpathians, the species is most numerous in forest habitats at altitudes from 500 to 900 m, i.e. on average higher than Lissotriton montandoni. In general, I. alpestris seems to have a narrower ecological niche than L. montandoni and a lower total population number. The daily activity is similar to that of Triturus and Lissotriton. Hibernation begins in September - October and ends in February (or earlier in the south) to May. The variation in timing and duration of active period depends on latitude and altitude. In highlands the activity period is shorter. The same applies for its reproductive period. In general, the courtship pattern of the Alpine Newt is more similar to that in Lissotriton vulgaris and Lissotriton montandoni than in the crested newts (Triturus cristatus superspecies). Adults and larvae tend to be bottom dwellers. The clutch contains probably 73-190 eggs deposited singly or in short chains of 3-5 eggs over a few days. In the Ukrainian Carpathians, metamorphosis occurs in September, later than in other newt species. However, larval hibernation and even neoteny (i.e. reproduction in the larval condition) occurs frequently in this species. Some populations in the mountains consist mostly of neotenic individuals. The sexual maturity in normal individuals is reported for the age of two or three years. Just after transition to active feeding, larvae of the Alpine Newt eat prey of the same taxa as larvae of the Carpathian Newt. During subsequent development, they consume increasing amounts of Mollusca, large forms of microcrustaceans (Daphniidae), and aquatic insects. In general, larval I. alpestris feed on more benthic prey than other syntopic larval newts. Feeding of adults is similar to that in other newts, such as those in the genus Triturus, and Lissotriton. Consumption of terrestrial prey by aquatic adults, as well as oophagy on nesting sites, is common.Dorsal crests in male newts (family Salamandridae) are particularly conspicuous during breeding season and their origin may be related to the complex courtship behaviors of these salamanders. In a new analysis that looks at many species and combines information on evolutionary relationships with data on morphology as well as behaviors, Wiens et al. (2011) reveal a complex relationship among these traits. The various dorsal crest traits (in mature males) that characterize different species have been lost repeatedly. The evolution of the dorsal crest may be related to certain specific behaviors such as fanning and whipping of the tail. Species with higher numbers of crest-related traits also have larger repertoires of courtship behaviors.
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Sergius L. Kuzmin
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AmphibiaWeb articles

Life History, Abundance, Activity, and Special Behaviors ( Inglês )

fornecido por AmphibiaWeb articles
Chemical pollution of wetlands, as well as destruction of habitats has led to the species' extinction from some localities. Reproduction in wheel ruts on country roads leads to population declines caused by high embryonic and larval mortality in the ruts. Mass collecting of newts for education and science has negatively influenced some populations.Newt habitat in the Montenegrin holokarst region (a rocky, dry habitat) has been steadily declining over the past several decades, as many ponds originally created for cattle drinking and human water consumption have been abandoned by humans (Ćirović et al. 2008).
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autor
Sergius L. Kuzmin
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AmphibiaWeb articles

Relation to Humans ( Inglês )

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In addition to the above mentioned factors, illegal trade in this species for terrarium amateurs previously took place in the former USSR. The extent of synanthropization seems to vary by the species' geographic populations.
licença
cc-by-3.0
autor
Sergius L. Kuzmin
original
visite a fonte
site do parceiro
AmphibiaWeb articles