The Italian crested newt (''Triturus carnifex'') is a species of

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 aqua ...

in the family Salamandridae.

Habitat

''Triturus carnifex'' is found in parts of the

Balkans The Balkans ( ), also known as the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throughout the who ...

and

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

. It is an aquatic breeder that can spend up to four months in the water.(Arntzen, J.W., Themudo, G.E., Wielstra, B. 2007. The phylogeny of crested newts (Triturus cristatus superspecies): nuclear and mitochondrial genetic characters suggest a hard

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...

, in line with the paleogeography of the centre of origin. Contributions to Zoology 76(4):261-278.) The location of the ponds where they breed affects the time when ''T. carnifex'' enters the water. ''T. carnifex'' prefers living in deep water since it is a

nektonic Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms t ...

species: it swims freely and is independent of currents. The absence of predatory fish may also explain why ''T. carnifex'' is inclined to ponds, rather than other larger bodies of water. They typically prefer ponds in northern Europe, where temperatures are colder . Adult ''T. carnifex'' start to arrive between February and May, and leave between July and October.(Andreone, F., and Giacoma, C. 1989. Breeding Dynamics of Triturus Carnifex at a pond in Northwestern Italy (Amphibia, Urodela, Salamandridae). Holarctic Ecology 12:219-223.) In warmer ponds, adult newts arrive within a month and leave during a two-week period in July. Andreone and Giacoma (1989) speculated that newt migration into the ponds increases after rainy days, since after rainfall, newt activity is not limited by humidity. Higher altitudes, where temperatures begin to decrease, have a direct effect on the size of ''T. carnifex''.(Ficetola, G. F., et al. 2010. Ecogeographical variation of body size in the newt Triturus carnifex: comparing the hypotheses using an information-theoretic approach. Global Ecology and Biogeography 19: 485-495.) Ficetola et al. (2010) discovered that living in colder temperatures resulted a body size increase in both male and female. Females in higher altitudes were found to be larger because they were carrying more

oocytes An oocyte (, ), oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The female g ...

and larger ovaries, which gave them a reproductive advantage over the smaller females. ''T. carnifex'' is

poikilothermic A poikilotherm () is an animal whose internal temperature varies considerably. Poikilotherms have to survive and adapt to environmental stress. One of the most important stressors is temperature change, which can lead to alterations in membrane ...

and larger body sizes help to reduce heat fluctuations. Ficetola also found that fluctuations in body temperature of T. carnifex decreased when body size increased. An increase in body size also occurs where there is increased precipitation or nearby primary producers, due to the effect of increased resources on animals. Human interference has dramatically changed the habitat of ''T. carnifex'' due to the expansion of industrial areas and urban centers.(Ficetola and Bernardi 2003) This results in a fragmentation of natural landscapes, which leads to selective extinction,

genetic drift Genetic drift, also known as allelic drift or the Wright effect, is the change in the frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene variants to disappear completely and there ...

, and inbreeding from isolation. Introducing fish to isolated wetland habitats also leads to a decline of amphibians because of predation on newt larvae.

Physiology

Adult newts in the genus ''Triturus'' were found to breathe mainly via the skin but also through the lungs and the

buccal cavity The buccal space (also termed the buccinator space) is a fascial space of the head and neck (sometimes also termed fascial tissue spaces or tissue spaces). It is a potential space in the cheek, and is paired on each side. The buccal space is super ...

. Lung breathing is mainly used when there is a lack of oxygen in the water, or at high activity such as during courtship, breeding, or feeding.(Eddy, F. B., P. McDonald. 1978. Aquatic respiration of The Crested Newt Triturus Cristatus. Comparative Biochemical Physiology. 59: 85-88) When ''T. carnifex'' newts are induced into

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, t ...

, they are able to respire without the need of blood cells.(Casale. G.P, Khairallah. E. A., Grasso. J. A. 1980. An Analysis of Hemoglobin Synthesis in Erythropoeitic Cells. Developmental Biology 80:107-119. ) Around two weeks after anemia is induced, the newts produces a mass of cells that helps to revitalize the already circulating

red blood cell Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

mass. During winter months,

prolactin Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pit ...

is released into the circulatory system, which drives ''T. carnifex'' into the aquatic environment and reduces the active transport of sodium ions.Lodi, G., Biciotti, M., and Viotto, B. 1981. Cutaneous Osmoregualtion in Triturus cristatus carnifex (Laur.) (Urodela). General and Comparative Endocrinology 46: 452-457. This happens because there is more water readily available to the newt for uptake as compared to its terrestrial dwelling during the summer months. In the aquatic phase, ''T. carnifex'' has a reduced urine flow and glomerular filtration rate compared to the terrestrial phase.(G. Lodi, M. Biciotti. 1985. Osmoregulatory adaptation of renal function in the terrestrial and aquatic phase crested newt (Triturus cristatus carnifex Laur. Bolletino di Zoologia. 52(3-4): 243-245.) In summer, aldosterone creates an increase in enzymatic activity in ''T. carnifex'', which leads to a decrease in ion transport.(G. Lodi, B. Dore, P. Usai, M. Biciotti. 1995. Ion transport processes and alkaline phosphatase activity in the skin of the crested newt. Bolletino di Zoologia. 62(2): 137-146.)

Behaviour and ecology

To avoid competition with other co-occurring newts, ''T. carnifex'' tends to reproduce in the deeper parts of a pond and is more nocturnal.(Fasola, M., 1993. Resource partitioning by three species of newts during their aquatic phase. Ecography 16: 73-81.) Due to their larger size, they can prey on smaller species such as the

palmate newt The palmate newt (''Lissotriton helveticus'') is a species of newt found in Western Europe, from Great Britain to the northern Iberian peninsula. It is long and olive or brown with some dark spots. The underside is yellow to orange, and the thr ...

.(Buskirk, J. 2007. Body size, competitive interactions, and the local distribution of Triturus newts. Journal of Animal Ecology 76:559-567.) Reproductive females of ''T. carnifex'' were shown to regulate their body temperature more precisely and prefer higher temperatures than non-reproductive females and males.(L. Gvozdik. 1995. Does reproduction influence temperature preference in newts. Canadian Journal of Zoology. 83(8): 1038-1044. doi: 10.1139/z05-096)

Sensitivity to pollutants

Cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

, a released into the environment from industrial and consumer waste, has been shown to be detrimental to ''T. carnifex'' even at a concentrations below Italian and European thresholds, by disrupting the activity of the

adrenal gland The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex whic ...

.(Gay, F., V. Laforgia, I. Caputo, C. Esposito, M. Lepretti, and A. Capaldo, “Chronic Exposure to Cadmium Disrupts the Adrenal Gland Activity of the Newt Triturus carnifex (Amphibia, Urodela),” BioMed Research International.) In experiments allowing Italian crested newts to be exposed to

nonylphenol Nonylphenols are a family of closely related organic compounds composed of phenol bearing a 9 carbon-tail. Nonylphenols can come in numerous structures, all of which may be considered alkylphenols. They are used in manufacturing antioxidants, lubr ...

, an endocrine disruptor common in leakage from sewers, there was a decrease in

corticosterone Corticosterone, also known as 17-deoxycortisol and 11β,21-dihydroxyprogesterone, is a 21-carbon steroid hormone of the corticosteroid type produced in the cortex of the adrenal glands. It is of minor importance in humans, except in the very rar ...

and aldosterone, hormones produced by the

and important for stress response.(A. Capaldo, F. Gay, S. Valiante, M. DeFalco, R. Sciarrillo, M. Maddaloni, V. Laforgia. 2012. Endocrine-disrupting effects of nonylphenol in the newt, Triturus carnifex (Amphibia, Urodela). Comparative Biochemistry and Physiology. 155(2): 352-358. doi: 10.1016/j.cbpc.2011.10.004)

References

External links

* * {{Taxonbar, from=Q660346 Triturus Amphibians described in 1768 Amphibians of Europe Taxonomy articles created by Polbot Taxa named by Josephus Nicolaus Laurenti