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: Albania, Austria, Bosnia and Herzegovina, Croatia, Czech Republic, Greece, Hungary, Italy, Macedonia, the Former Yugoslav Republic of, Montenegro, Serbia, Slovenia, Switzerland. Introduced: Netherlands, Portugal, United Kingdom.
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)
Citation: AmphibiaWeb: Information on
amphibian biology and conservation. [web application]. 2013. Berkeley, California:
AmphibiaWeb.
Available: http://amphibiaweb.org/.
(Accessed: Jun 18, 2013).