Description

ADULT MORPHOLOGY:

Triturus ivanbureschi is a relatively robust crested newt with a snout-to-anterior-vent length range of 52.0 - 63.0 mm in males and 51.5 - 65.0 mm in females. The snout-to-posterior-vent length range is 58.5 - 62.5 mm in males and 56.0 - 71.0 mm in females. The total length range is between 87.5 - 109.5 mm in males and 96.0 - 122.5 mm in females. The head is longer than wide. Their gular fold along their ventral throat is concealed. Most of the individuals had thirteen rib-bearing presacral vertebrae, however, a few have 14, including the holotype. The inter-limb distance had a range of 26.5 - 29.0 mm in the males and 26.0 - 33.0 mm in the females. Their skin along the dorsal and lateral sides and throat has a roughened texture while the tail and venter are smooth. The range of measurement for the right arm to the tip of the third finger is between 21.1 - 22.4 mm in the males and 17.3 - 22.8 mm in the females. They have four fingers with relative lengths from shortest to longest being first, fourth, second, and then third finger. The length of the right third finger ranged from 7.7 - 8.8 mm in the males and 5.8 - 8.0 mm in the females. Their fingers and toes are fringed, but lack interdigital webbing. The range of the right leg length to the fourth toe is between 21.4 - 24.1 mm in the males and 18.1 - 22.4 mm in the females. They have five toes with relative lengths from shortest to longest being first, fifth, second, fourth, and then third toe. The length of the right toe ranged from 7.5 - 9.6 mm in the males and 6.1 - 8.1 mm in the females. Their tail is laterally compressed with a noticeable dorsal fin and less apparent ventral fin (Wielstra et al. 2013).

DIAGNOSIS:

Triturus ivanbureschi is included in the genus Triturus because it shares the common characteristics of other crested newts of the T. cristatus superspecies. These characteristics include a denticulated crest, a dark brown coloration on their dorsal surface, and an orange coloration along their ventral sides dotted with black. Triturus ivanbureschi can only be distinguished from its sister taxon T. karelinii using mitochondrial DNA sequence data (Wielstra et al. 2013).

COLORATION:

In life, they have a dark brown, almost black, base color on their dorsal and lateral sides, marbled with black dots that are more noticeable on their head. Their ventral side and throat are a bright orange color with angular black dots scattered around. The dots on their throat are smaller and more clustered than the spots on their belly. Along the lateral sides of their tail they have a blueish-white streak. In preservation, these colors have slightly faded and are muted (Wielstra et al. 2013).

VARIATION:

Males in the species exhibited a swollen cloaca that had papillae bordering the opening, while the females did not have a swollen cloaca, but the papillae were still present. The females also lacked a denticulated crest, which was described in the males, and had an even less apparent tail fin compared to the males (Wielstra et al. 2013).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Bulgaria, Greece, Macedonia, the Former Yugoslav Republic of, Serbia, Turkey

View distribution map in BerkeleyMapper.

Triturus ivanbureschi is found in far eastern Europe and far western Asia. The European populations are distributed throughout the south-eastern Balkan Peninsula in most of Bulgaria, eastern Greece, European Turkey, as well as Macedonia and Serbia (Wielstra et al. 2013). The Asian populations are in north-western Turkey along the coastlines of the Aegean Sea and the western and central coastlines of the Marmara Sea (Lukanov and Tzankov 2016, Natchev et al. 2016). They are generally found at elevations between 857 - 1700 m. However, this species has also been observed in regions across Bulgaria from sea level all the way to 1,700 m in elevation (Lukanov and Tzankov 2016). Triturus ivanbureschi is typically found inhabiting still ponds with thick vegetation in their surroundings (Natchev et al. 2016).

Life History, Abundance, Activity, and Special Behaviors
Triturus ivanbureschi is typically found inhabiting still ponds with thick vegetation (Natchev et al. 2016). However, they are found across various environmental conditions. For example, they could live in Bistritsa with long dry summers, and German ponds with longer water periods (Lukanov and Tzankov 2016). In the early developmental stages, individuals are aquatic (Vučić et al. 2022). But when they grow older, they likely live in a terrestrial environment (Lukanov et al. 2018).

Triturus ivanbureschi prefer larger ponds (~27 m in diameter) compared to smaller ones (< 9 m in diameter) (Lukanov et al. 2021). However, near Bistritsa, the ponds that T. ivanbureschi populations lived in were only three by two meters around and one meter deep; and sometimes were polluted with industrial waste due to the nearby settlement. The surrounding area was scattered with rocks and stones of many sizes and dominated by open vegetation such as plants from the families Poaceae and Rosaceae. Near Germany, the ponds were about 45 by 30 m around and one meter in depth. Farther from village settlements these ponds had less pollution, were on less rugged terrain, and were surrounded by more forest vegetation such as plants in the families Fagacecae and Betulacae. Overall, T. ivanbureschi appears to inhabit various types of habitats (Lukanov and Tzankov 2016).

In natural environments, females produce individual eggs and wrap them with submerged vegetation (Vučić etl. 2022). The size of individual eggs are related to the location of the species. For example, eggs in Bistrita are larger on average and are more variable (1.56 mm³ - 13.36 mm³) compared with egg samples from German (1.86 mm³ - 8.65 mm³) (Lukanov and Tzankov 2016).

Triturus ivanbureschi has indirect development and matures with metamorphosis. From a fertilized egg to hatching takes about 16 days (Lukanov and Tzankov 2016). It needs 88 days to finish the metamorphosis. The external gills reduce and five digits in hind limbs form in 104 days from fertilization (Lukanov and Tzankov 2016).

They hibernate in winter (Vučić et al. 2022).

Trends and Threats
Triturus ivanbureschi has not been assessed by the IUCN Red List. However, the literature indicates that there are several threats to the species, including general habitat loss, climate change, and loss of fitness and genetic distinctiveness due to hybridization (Nori et al. 2015, Kafash et al. 2018, Vučić et al. 2022).

Human activities in their terrestrial and aquatic habitats have largely threatened the niches available for these forest dwelling amphibians. Habitat fragmentation by human conversion of land for agricultural use impacts T. ivanbureschi migration patterns, which may be further impacted by climate changes (Nori et al. 2015). The ongoing human induced changes to the landscape will continue to have negative and irreversible impacts on the amphibian conservation if no further action is taken.

Triturus ivanbureschi is found in some protected areas. However, a habitat model predicts that ​​T. ivanbureschi will lose approximately 74% of its current range to climate change including a projected decrease in protected areas by 22% and 49.2%. As a forest-dwelling amphibian species that is sensitive to changes in their surrounding ecosystem, T. ivanbureschi is predicted to have a contracted geographic distribution in response to disturbed rainfall and temperature due to abnormal climate change (Kafash et al. 2018).

Triturus ivanbureschi has been documented to hybridize with T. macedonicus in central Serbia. Even though the hybrid pairings have larger numbers of offspring and larval survival, studies on this hybridization have shown impacts on physiological traits and thus decrease in survival in their offspring over generations. Additionally, hybrid larvae exhibited raised oxidative stress parameters and an overall slower growth rate (Vučić et al. 2022).

Triturus ivanbureschi and T. anatolicus share a hybrid zone in northwestern Turkey (Wielstra and Arntzen 2016).

Possible reasons for amphibian decline

General habitat alteration and loss
Intensified agriculture or grazing
Urbanization
Habitat fragmentation
Disease
Loss of distinctiveness through hybridization
Climate change, increased UVB or increased sensitivity to it, etc.

Comments

PHYLOGENETIC RELATIONSHIPS:

Triturus ivanbureschi was previously considered a part of T. karelinii. However, a survey of mitochondrial and nuclear DNA analyses and found that there was a deep divergence between the two species. The eastern lineage is now considered T. karelinii, and the central/western lineage was then considered T. ivanbureschi. However, the central/western lineage was further divided into two distinct lineages. Based on single and mulitlocus Neighbor Joining analyses and Bayesian Inference, using ND4 mtDNA and nuclear introns (beta-Fibrinogen intron 7, Calreticulin intron C, and Platelet-derived growth factor receptor a intron11) T. ivanbureschi is most closely related to T. anatolicus. The clade composed of the two species is sister to T. karelinii (Wielstra et al. 2013, Wielstra and Arntzen 2016).

ETYMOLOGY:

The species epithet, “ivanbureschi,” is in honor of the late Dr. Ivan Buresch. He died in 1980 and was the scientific director at the Institute of Zoology in Sofia, Bulgaria. Dr. Buresch and his assistant Jordan Zonkov were responsible for the inception and groundwork of herpetology in Bulgaria, especially in the Balkan region (Wielstra et al. 2013).

References

Kafash, A., Ashrafi, S., Ohler, A., Yousefi, M., Malakoutikhah, S., Koehler, G., Schmidt, B.R. (2018). “Climate change produces winners and losers: Differential responses of amphibians in mountain forests of the Near East.” Global Ecology and Conservation, 16:e00471. [link]

Lukanov, S., Doncheva, T., Kostova, N., Naumov, B. (2021). "Effects of selected environmental parameters on the activity and body condition of the Buresch's crested newt (Triturus ivanbureschi) with notes on skin secretions." North-Western Journal of Zoology, 17(1), 34-38. [link]

Lukanov, S., Tzankov, N. (2016). "Life history, age and normal development of the Balkan-Anatolian crested newt (Triturus ivanbureschi Arntzen and Wielstra, 2013) from Sofia district." North-Western Journal of Zoology, 12(1), 22-32. [link]

Natchev N, Handschuh S, Lukanov S, Tzankov N, Naumov B, Werneburg I. (2016). "Contributions to the functional morphology of caudate skulls: kinetic and akinetic forms." PeerJ 4:e2392 [link]

Nori, J., Lemes, P., Urbina-Cardona, N., Baldo, D., Lescano, J., Loyola, R. (2015). "Amphibian conservation, land-use changes and protected areas: A global overview." Biological Conservation, 191, 367-374. [link]

Vučić, T., Ivanović, A., Ajduković, M., Bajler, N., Cvijanović, M. (2022). "The reproductive success of Triturus ivanbureschi× T. macedonicus F1 Hybrid Females (Amphibia: Salamandridae)." Animals, 12(4), 443. [link]

Wielstra B, Arntzen JW (2016). ''Description of a new species of crested newt, previously subsumed in Triturus ivanbureschi (Amphibia: Caudata: Salamandridae).'' Zootaxa, 4109, 73-80.

Wielstra, B. Baird A.B. Arntzen J.W. (2013). "A multimarker phylogeography of crested newts (Triturus cristatus superspecies) reveals cryptic species." Molecular Phylogenetics and Evolution, 67(1), 167-175. [link]

Wielstra, B., Litvinchuk, S. N., Naumov, B., Tzankov, N., Arntzen, J. W. (2013). "A revised taxonomy of crested newts in the Triturus karelinii group (Amphibia: Caudata: Salamandridae), with the description of a new species." Zootaxa, 3682(3), 441-453. [link]

Species Account Citation: AmphibiaWeb 2022 Triturus ivanbureschi: Balkan Crested Newt; Buresch's Crested Newt <https://amphibiaweb.org/species/8024> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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