Description

Triturus carnifex, the Italian Crested Newt, is a large newt, with females measuring up to 180 mm and males up to 150 mm in total length (Arnold 2002). The subspecies T. carnifex carnifex is dark brown with black spots, and has an orange to orange-yellow belly with large rounded dark spots. In contrast, the subspecies T. carnifex macedonicus has smaller and more dense dark belly spots (Edgar and Bird 2006). Triturus carnifex adult females may have a bright yellow vertebral stripe (Arnold 2002). As in other crested newt species, T. carnifex males develop a pronounced dorsal crest during breeding season (Arnold 2002).

Triturus carnifex is one of four species within the crested newt species complex (T. carnifex, T. cristatus, T. dobrogicus, T. karelinii). It is most similar in appearance and size to Triturus cristatus, the Great Crested Newt. Triturus carnifex can be distinguished by a broader tail base, larger legs, and smoother skin than T. cristatus (Edgar and Bird 2006). In addition, T. carnifex has 15 vertebrae that bear ribs, while T. cristatus has 16 rib-bearing vertebrae (Arntzen and Wallace 1999).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Austria, Bosnia and Herzegovina, Croatia, Czech Republic, Hungary, Italy, Slovenia. Introduced: Switzerland, United Kingdom.

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (66 records).

Triturus carnifex is native to Italy, south-central Europe, and the western Balkans (Edgar and Bird 2006). It is also found in France/Switzerland, in the Lake Leman/Lake Geneva region, though it is thought that this population has been introduced (Edgar and Bird 2006). A population of T. carnifex has also been established in the U.K., at Surrey, for some years, most likely escaped from the pet trade (Lever 1980; Brede et al. 2000).

This species makes use of a wide variety of habitats, including dry Mediterranean regions and beech woodlands, at altitudes up to 2140 meters (Arnold 2002; Edgar and Bird 2006). Triturus carnifex strongly prefers still waters for breeding, either temporary or permanent, but will use pools within streams, or rivers with slow flow if necessary (Edgar and Bird 2006). Artificial water bodies may also be used, such as garden ponds and water-filled gravel pits. In parts of northern Italy, T. carnifex has also been found within rice paddies (Andreone and Marconi 2006).

Triturus carnifex tolerates a much wider range of habitat than the related species T. cristatus. Triturus carnifex does not require cover, can make use of pools regardless of whether there is aquatic vegetation present, and generally is able to thrive in disturbed habitat (Arntzen and Thorpe 1999). Arntzen and Thorpe (1999) found that in disturbed areas around Lake Geneva/Lake Leman (Switzerland), the introduced T. carnifex had outcompeted native T. cristatus to become the dominant species.

Life History, Abundance, Activity, and Special Behaviors

Crested newts are primarily nocturnal and partially aquatic (Edgar and Bird, 2006)[3772].Triturus carnifex spends an average of four months a year in water, during the spring (Edgar and Bird 2006). Breeding occurs during this time, and females each lay about 250 eggs (Edgar and Bird 2006). Due to a lethal mutation on the first chromosome, the whole species complex experiences 50% mortality during egg development (Wallace 1994; D'Amen et al. 2006). Triturus carnifex is able to interbreed with other species of crested newts, especially T. cristatus (Arntzen and Thorpe 1999; Brede et al. 2000).

Paedomorphic populations of T. carnifex macedonicus have been reported to occur, though these appear to be very rare. So far they have only been described from a few locations in Greece (Edgar and Bird 2006).

During the terrestrial phase, the adult diet consists of terrestrial invertebrates (insects, earthworms, woodlice, molluscs) (Edgar and Bird 2006). During the aquatic phase, adult crested newts feed on aquatic invertebrates, juvenile newts, and tadpoles, and have also been reported to consume shed amphibian skin. Crested newt larvae will eat frog tadpoles and other larval salamanders, in addition to a wide range of aquatic invertebrates (Edgar and Bird 2006).

Adult crested newts have toxic skin secretions, as do all members of the family Salamandridae (Duellman and Trueb 1994). Nonetheless, they are consumed by a range of predators (Edgar and Bird 2006). Crested newt larvae tend to be pelagic (swim freely) rather than hiding, rendering larvae more vulnerable to aquatic predators (Edgar and Bird 2006).

Trends and Threats
The crested newt species are among the most rapidly declining amphibian taxa in Europe and are protected by law (Edgar and Bird 2006). They are particularly vulnerable to habitat fragmentation due to their inability to move long distances (Edgar and Bird 2006). In addition, T. carnifex is highly sensitive to changes in water quality (IUCN 2006). Thus another principal threat to this species is loss of aquatic habitat due to pollution. Larval crested newts are also particularly susceptible to predation by fish (Edgar and Bird 2006).

Possible reasons for amphibian decline

General habitat alteration and loss
Intensified agriculture or grazing
Habitat fragmentation
Local pesticides, fertilizers, and pollutants
Predators (natural or introduced)

References

Andreone, F., and Marconi, M. (2006). ''Triturus carnifex.'' Atlante degli Anfibi e dei Rettili d’Italia (Atlas of Italian Amphibians and Reptiles). Societas Herpetologica Italica, Edizioni Polistampa, Firenze, 220-225.

Arnold, N. (2002). Reptiles and Amphibians of Europe. Princeton University Press, Princeton.

Arntzen J. W., and Thorpe R. S. (1999). ''Italian Crested Newts Triturus carnifex in the basin of Geneva: Distribution and genetic interactions with autochthonous species.'' Herpetologica, 55(4), 423-433.

Arntzen, J.W., and Wallace, G.P. (1999). ''Geographic variation and taxonomy of crested newts (Triturus cristatus superspecies): morphological and mitochondrial DNA data.'' Contributions to Zoology, 68(3), 1-15.

Brede, E. G., Thorpe, R. S., Arntzen, J. W., and Langton, T. E. S. (2000). ''A morphometric study of a hybrid newt population (Triturus cristatus/T.carnifex): Beam Brook Nurseries, Surrey, U.K.'' Biological Journal of the Linnaean Society, 70, 685-695.

D'Amen, M., Vignoli, L., and Bologna, M. (2006). ''The normal development and the chromosome No. 1 syndrome in Triturus carnifex carnifex (Caudata, Salamandridae).'' Italian Journal of Zoology, 73(4), 325-333.

Duellman, W. E., and Trueb., L. (1994). Biology of Amphibians. Johns Hopkins University Press, Maryland.

Edgar, P., and Bird, D. R. (2006). ''Action Plan for the Conservation of the Crested Newt Triturus cristatus species complex in Europe [Internet]. Convention on the Conservation of European Wildlife and Natural Habitats. Strasbourg, 2006 Nov 26-30.'' Cited 2007 Apr 2. Available at http://www.coe.int/t/e/cultural_co-operation/environment/nature_and_biological_diversity/nature_protection/sc26_inf17_en.pdf.

IUCN, Conservation International, and NatureServe. 2006. Global Amphibian Assessment. www.globalamphibians.org. Accessed on 2 April 2007.

Lever, C. (1980). ''Observations at Beam Brook Nurseries.'' British Herpetological Society Bulletin, 1(6), 21-23.

Wallace, H. (1994). ''The balanced lethal system of crested newts.'' Heredity, 73, 41-46.

Species Account Citation: AmphibiaWeb 2021 Triturus carnifex: Italian Crested Newt <https://amphibiaweb.org/species/4294> University of California, Berkeley, CA, USA. Accessed Nov 24, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Nov 2024.

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