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The article presents the results of histological examinations of the digestive organs Triturus vulgaris, which have morphological features depending on the type of organ. It is established that the organs of the digestive tract have a typical structure of the tubular organs. The esophagus, stomach, small and large intestines consist of three membranes: mucous (epithelium, own and muscular plate, submucosal basis), muscular and serous, or adventitial. Digestive glands have a typical structure of parenchymal organs. Their parenchyma has specific features of structural and functional units.

We document the successful establishment of a European newt (Lissotriton vulgaris) in south-eastern Australia, the first recorded case of a caudate species establishing beyond its native geographic range in the southern hemisphere. Field surveys in south-eastern Australia detected L. vulgaris at six sites, including four sites where the species had been detected 15 months earlier. Larvae were detected at three sites. Individuals had identical NADH dehydrogenase subunit 2 and cytb mtDNA gene sequences, and comparisons with genetic data from the species’ native range suggest that these individuals belong to the nominal subspecies L. v. vulgaris. Climatic conditions across much of southern Australia are similar to those experienced within the species’ native range, suggesting scope for substantial range expansion. Lissotriton vulgaris had been available in the Australian pet trade for decades before it was declared a ‘controlled pest animal’ in 1997, and thus the invasion documented here likely originated via the release or escape of captive animals. Lissotriton vulgaris is the sole member of an entire taxonomic order to have established in Australia, and given the potential toxicity of this species, further work is needed to delimit its current range and identify potential biodiversity impacts.

By replacing parts of the neural plate (prospective medulla oblongata) of Triturus vulgaris by neural ectoderm of Xenopus laevis larval chimaeras were obtained, which showed donorlike rhythmical movements of distinct parts of the visceral musculature according to the place of implantation. Especially the branchial region with its external gills showed rhythmical movements and is the special object of this investigation.

Competition between unmated females for males was observed in the smooth newt, T. vulgaris, during the early part of the breeding season. Females interfered at the spermatophore-transfer stage of courtship, preventing a rival female from picking up the sperm mass. Interference often resulted in the rival female abandoning the courtship encounter. In many of the encounters (70%), the interfering female was inseminated. However, interference between females was not observed after the commencement of ovulation. By contrast, the incidence of sexual interference between males was low during the preovulatory period and increased significantly post-ovulation. Sexual interference in newts and salamanders has previously only been observed between males. During the greater part of the breeding season, when females are ovipositing, eggs are the limiting resource and males compete for access to receptive females. However, this study suggests that early in the breeding season, prior to commencement of ovulation, the limiting resource may temporarily be sperm, due to the physiological constraint of spermatophore production. This may lead to female competition for mates.

In organisms lacking parental care or when eggs of more than one female are layed together, parents preferentially tend to avoid eating their own offspring. In some species of newts (Caudata: Salamandridae), there is no parental care and cannibalism of eggs and larvae occurs when philopatric adults remain in the pond throughout the breeding season where eggs and larvae develop. Kin discrimination by both adult newts and larvae would be expected to occur during the breeding season as it would enable individuals to benefit from the nutrients obtained from eating eggs and larvae while they avoid eating close relatives. The effects of kinship on cannibalism of eggs and larvae were examined in two species of newts. In separate, but similar, paired behavioral trials adult female red-spotted newts, Notophthalmus viridescens, and smooth newts, Triturus vulgaris, were allowed to consume their own egg or an egg from another female. Female red-spotted newts, but not smooth newts, preferred to eat eggs of other females rather than their own, and overall smooth newts were ‘reluctant’ to eat conspecific eggs. To test for ontogenetic shifts in discrimination abilities, additional experiments were performed with adult female red-spotted newts paired with their own larvae and a larva from another female. In addition, the effects of kinship on the attraction or repulsion of larvae was also studied in red-spotted newts. Females showed no significant discrimination abilities during acts of cannibalism on larvae. Larvae spent similar amounts of time with siblings and non-siblings. These results suggest that the ability of adult newts to discriminate among eggs varies between species and that the elicitation of a kin-discrimination response may be context-dependent. For red-spotted newts, there was no evidence of discrimination abilities within and between other life-history stages.

and Summary 1 When a male smooth newt encounters a ♀ who is already engaged in courtship, he may mimic her behaviour during the spermatophore deposition and transfer stages of the courtship. He thereby usurps the courting ♂ and may inseminate the ♀ himself. Such sexual interference depresses the short-term, and perhaps long-term, mating success of the courting ♂. 2 In the presence of a potential rival, the courting ♂ alters certain aspects of his sexual behaviour. He displays more intensely to the ♀ and attempts to draw her away from the rival by increasing the duration of his display. He may also “check” that it is the ♀, and not the rival, who will elicit the deposition of a spermatophore from him. These changes in the behaviour of the courting ♂ are interpreted as defense against sexual interference. 3 Female smooth newts may be multiply inseminated as a consequence of sexual interference; this may result in sperm competition. However, ♀♀ seem to find competitive interactions between ♂ ♂ “aversive”. 4 Sexual interference by ♀-mimicry and associated defensive behaviour patterns are common in the urodele amphibians. Interference can be thought of as a “side-payment” conditional mating strategy.

In the city of Walbrzych 67 water bodies (about 95% of all Walbrzych ponds) were investi-gated. Among them, 58 water bodies (86.57%) are of anthropogenic origin. In the studied area 9 amphibian species were recorded: Rana temporaria (present in 44.78% of studied water bodies), Bufo bufo (44.78%), Triturus vulgaris (17.91%), Trirutus alpestris (16.62%), water frogs of the Rana esculenta complex (Rana lessonae and Rana kl. esculenta, 10.45% altogether), Bufo viridis (10.45%), Bufo calamita (4.48%) and Triturus cristatus (4.48%). Amphibians were present in 48 ponds (71.64% of studied water bodies). Maximum number of species (six) was recorded in only 1 water body; minimum number of species (1) was recorded in 19 ponds. Surprisingly, the maximum number of species occurred in the pond located within dense urban area. One bank of this pond was a vertical brick wall and there is not much vegetation in the pond. In industrial areas of Walbrzych presence of only 5 amphibian species was noted, however on 7 sites there were no amphibians atall. Similar low number of amphibian species (five) was also noted in mini-ponds in the allotments.

The paper presents information about the amphibian species in Wroclaw – frequency oftheir occurrence as well as number of individuals in water bodies. For the study 31 sites were selected. Only in two sites no amphibians were found. On the rest of the sites in total 11 amphibian taxons were present – Triturus cristatus, Triturus vulgaris, Bombina bombina, Bufo bufo, Bufo viridis, Hyla arborea, Pelobates fuscus, water frogs from the Rana esculenta complex (both a species Rana lessonae and a hybrid Rana kl. esculenta), Rana temporaria and Rana arvalis. The most numerous were water frogs (occurred on 90.3% of all sites), Bufo bufo (48.4% sites), Bombina bombina and Rana temporaria (both species on 45.2% si- tes). The rarest species were Triturus cristatus (16.1% sites) and Pelobates fuscus (9.7% sites). In Wroclaw amphibians are the most abundant in ponds located within river valleys. There are 10 species there (on the average 4.44 species per pond), with Bombina bombina and water frogs being the most numerous. Second amphibian-friendly environment are sites within the city forests, having 8 species (on the average 5.22 species). Water frogs, Rana temporaria and Rana arvalis were most common here, and Triturus cristatus and Triturus vulgaris occurred mostly in this category. The lowest frequency was observed in the city center (on the average 0.66 species), with one site without any amphibians, and with only water frogs in the remaining two sites. After a pond reconstruction populations of Triturus vulgaris and Bufo bufo disappeared, and the number of Bufo viridis increased. For three sites the changes in amphibian species assemblages in consecu- tive years of observations are provided. In two sites the trend of maintaining the same species composition was observed, and on third site the composition changed due to the pond reconstruction (T. vulgaris and B.bufo substituted by B. viridis).

Aim We explored general habitat-related explanations (niche breadth and niche position) to the contrasting status of two amphibian species that have largely overlapping ranges and habitats – the rare and declining crested newt (Triturus cristatus), and the more common smooth newt (Triturus vulgaris). These closely related and ecologically similar species provide an excellent opportunity to study those methodologically challenging hypotheses, and this is the first such study on amphibians. Location Denmark. Methods We derived multivariate habitat models from 27 characteristics of 210 ponds and their surroundings, and their occupation by newts. In addition to the model performance, niche breadths were compared using the mean beta diversity of amphibian communities in the presence of each newt species. Results For each newt species, the habitat models comprised three variables and correctly classified 74% of observations. Diverse invertebrate fauna (prey base) and shorter distances to other ponds inhabited by conspecifics were positive for both species, while the surrounding habitat (notably dry grasslands with forests) was important for the crested newt and the sediment type of the pond for the smooth newt only. Beta diversity of the amphibian communities of occupied ponds did not differ between the two newt species. Hence, in an area of frequent coexistence, habitat requirements of the species differed in key variables, not in the extent of specialization. Main conclusions Our study supported the niche position rather than the niche-breadth hypothesis of rarity. We suggest that the rarity and/or continuing decline of the crested newt is related to the degradation of (semi)natural terrestrial habitats around suitable water bodies in Europe. Consequently, special restoration of such habitats has a high potential for the recovery of this rare species, while general pond management appeared more beneficial for the common smooth newt.

This paper describes the occurrence of hybridization and introgression in two species of amphibians (the newts Trifurus helrelicus and Trirurus culgaris) in mid-Wales, northern France and western France. A single aberrant adult male with intermediate phenotype was found. The multivariate analysis of 14 morphometric and two meristic characters supported its hybrid status. Electrophoretic analysis of 42 protein loci showed a genetic distance of 0.57 _+ 0.14 Nei units between the species and revealed 15 diagnostic loci. The aberrant specimen was heterozygous at 1 I of those and most likely to be a F, hybrid. Four marker loci appeared homozygous, suggesting the presence of enzymatically non-active (‘null‘) alleles. The analysis of (maternally inherited) mitochondrial DNA showed the hybrid to be the offspring of a T. heltleticus mother (and a T. vulgaris father). This observation does not conform to expectations based on the species composition in the pond from which the hybrid was collected. No F, hybrids were observed in a large sample (n > 5000) of larvae, recently metamorphosed newts and adults using two diagnostic protein loci. Occasionally alleles characteristic for one species were observed in the gene pool of the other species, suggesting the presence of bidirectional introgression. However, the frequency of alien genes was low (maximally 0.07%) which renders it difficult to rule out alternative explanations conclusively. The increase in total genetic variation in T. helveticus and T. vulgaris due to gene flow between them is negligible.

Facultative paedomorphosis, a process in which newt larvae can opt for reproduction before or after metamorphosis, is geographically heterogeneous. Despite numerous ecological studies and recent evidence of declines in paedomorphic populations, however, no attempt to model environmental variables that explain the presence of paedomorphs has been made at a multi-scale level. Our aim was to fill this gap in studying three newt species (Lissotriton vulgaris, Mesotriton alpestris, and Triturus macedonicus) of the Montenegrin karst as model species. To this end, we used multivariate analysis on three scales of habitat: the breeding pond, the land use and the climatologic features. Results show that the study area is both an important hotspot for paedomorphosis and where intraspecific diversity is quickly disappearing (20-47% extirpation) because of fish introductions. Other habitat variables (water permanency, pH or the habitat origin) were shown to act on paedomorphosis but not consistently across species, confirming complexity of the evolutionary and ecological processes. This study appeals for more long-term and detailed landscape studies of polyphenisms, a neglected but promising topic, to better understand and protect alternative modes of development. Particularly, measures should be taken to identify hotspots of intraspecific diversity at a global scale and stop fish introductions before we reach a point of no-return.

We examined the density of 2 endangered amphibians, natterjack toads (Bufo calamita) and yellow-bellied toads (Bombina variegata), in 150 breeding pools at each of 2 military training areas in the German state of Bavaria. We selected pools to ensure a wide range of observable ground disturbance resulting from military vehicular traffic during cross-country maneuvers. Both species exhibited significant affinity for pools with high levels of ground disturbance. Natterjack toads preferred pools with 80–100% ground disturbance; yellow-bellied toads preferentially occupied pools with 40–100% ground disturbance. Pools occupied by the target species were characterized by higher levels of bare ground and minimal vegetation. Among other observed amphibians, European edible frogs (Rana esculenta) preferred pools with ≤60% ground disturbance, less bare ground, more vegetative cover, and disturbance >2 years old. Common tree frogs (Hyla arborea), smooth newts (Triturus vulgaris), and alpine newts (T. alpestr...

Tetrodotoxin (TTX) and its analogue 6- epi tetrodotoxin (6- epi TTX) were quantitatively assayed in 59 newts representing four Triturus species ( Triturus alpestris , Triturus cristatus , Triturus helveticus , Triturus vulgaris ) from southern Germany by a post-column fluorescent-HPLC system. Both toxins were detected in only 15 specimens of the four species. The toxins levels varied considerably among individuals (TTX: 0.11–9.0 μg/g; 6- epi TTX: 0.05–17.0 μg/g). 6- epi TTX was found to be the major component.

Larval Bufo bufo (L., 1758) and Triturus vulgaris (L., 1758) were exposed to soft water (0.5 mg·L–1 Ca2+) experimentally acidified to pH 3.9 to 5.9 and total aluminium concentrations of –1. Below pH 4.5 both species experienced increased mortality. The LC50 (168 h) for –1 Al was pH 4.3 and 4.1 for B. bufo and 4.2 and 4.1 for T. vulgaris. However, Al3+ increased the survival of both species, which may be due to the contribution of Al3+ to the ionic strength. No B. bufo larvae died at pH >4.5, whereas T. vulgaris at higher Al concentrations suffered relatively high mortality at pH 5.1–5.9, where Al occurs mainly as Al(OH)2+ and Al(OH)2+. Unlike external gills (T. vulgaris), internal gills (B. bufo) have their own internal environment and are probably better protected against the presence of these toxic Al species in the water. These Al species thus seem to be toxic to T. vulgaris larvae but not to B. bufo. Chloride was seen to be important for survival in water of low ionic strength, since the survival of T. vulgaris larvae, particularly at low Al concentration, increased at pH levels down to pH 4.3 when the water was acidified with HCl.

Climate and weather affect phenological events in a wide range of taxa, and future changes might disrupt ecological interactions. Amphibians are particularly sensitive to climate, but few studies have addressed climatically mediated change in the phenology of closely related species or sexes. Here, we test the hypothesis that changes in spring temperatures result in phenological change among Triturus, and we examine inter- and intraspecific differences in response. Coexisting populations of Triturus helveticus and Triturus vulgaris at Llysdinam pond in mid-Wales (5311205900N 31270300W) were monitored using pitfall traps along a drift fence during 1981–1987, and again in 1997–2005. Spring temperature over the same period explained up to 74% of between-year variability in median arrival date, with a significant advance of 2–5 days with every degree centigrade increase. Changes were greater for males than females of both species, and greater for T. helveticus than T. vulgaris within sexes, resulting in an increasing temporal separation between arrivals of male T. helveticus and all other groups. These data illustrate for the first time how climatic change might have differential effects on sympatric species and on the two sexes.

Amphibian populations are declining at an alarming pace in many parts of the world. Consequently, as part of the strategy for establishing a 360 km2 conservation and reference area for amphibians in central Norway, 341 lentic water bodies were surveyed to investigate and briefly describe their hydrography and the occurrence of the newts Triturus vulgaris (L.) and T. cristatus (Laurenti) in the area. In particular we investigated the factors that could explain the presence of the respective newt species, including biotic and abiotic factors. The multiple logistic regression analyses suggested that the presence of T. cristatus was best explained by altitude and ion concentration, both in a nonlinear fashion, whereas fish had a negative effect on T. cristatus, which was never found coexisting with fish. The presence of T. vulgaris was best explained by altitude (linear relationship) and ion concentration (convex relationship), besides the occurrence of T. cristatus. Triturus vulgaris was occasionally found to occur at low densities in ponds having fish. For both species the probability of presence was higher when the opposite newt species was present. pH influenced both species in a convex nonlinear fashion with highest probability of presence around pH 6.5. This area is valuable for conservation, monitoring and reference for marginal amphibian populations. Any decline in their abundance would be discovered relatively quickly, and likely causes could be inferred. It can also serve as a reference area for future comparative studies of amphibians elsewhere.

DNA-based genetic markers can reveal paternity whenever the direct assignment of fathers to offspring is precluded by multiple matings and internal fertilisation. Microsatellites are the current marker of choice in many behavioural studies, and have revealed important insights into genetic mating systems of European amphibians. However, the number of amphibian species for which the time-consuming designing of locus-specific microsatellite primers was successful is still limited, and the cross-utilisation of existing markers to closely related taxa seems to have a particularly low success rate. Allozymes can infer parentage without a species-specific protocol, but, due to their low degree of polymorphism, in mate choice experiments require the a priori screening of individuals. Dominant markers such as RAPDs successfully identified closely-related amphibian species and their hybrids, but might be less suited to distinguish between closely related individuals with a putatively high frequency of shared bands.

In the years 2003–2005, the diversity of amphibian species in Kozienice Forest was analyzed. Thirteen species of amphibians were found in 91 different water habitats. The most common were Rana esculenta , R. temporaria and Bufo bufo, the rarest Triturus vulgaris , B. viridis and T. cristatus. We confirmed the presence of all species which had been found in this area in the beginning of 70s. Beside the check-list of amphibians of this area, we recognized their preferences for several important features of the studied water habitats. The most obvious, was the tendency of green frogs, for inhabiting large and stable water bodies. The differences in species diversity and relative abundance between Kozienice Landscape Park and other protected forests were discussed. Key words: amphibians, distribution, Kozienice Landscape Park, habitat preferences, species richness I NTRODUCTION Sudden extinctions of amphibian species and decline of their local populations have been observed for the last 20–30 years. Since early1990s, many studies have focused on global patterns of amphibian declines (Barinaga 1990, Wake 1991, Pechmann & Wilbur 1994). It is suspected that several interacting causes rather than one common reason have led amphibian populations and species to extinction. Six major hypotheses existing in the literature may be sorted into two categories. The first category indicates factors that directly interact with amphibian population, like land use changes, commercial over-exploitation, emerging infectious diseases and alien species. To the second category belong factors which indirectly affect amphibians: chemical pollutions, increased UV radiation and global climate change (Collins & Storfer 2003). Published papers have reported declining populations and extinction of amphibian species everywhere: in South and North America (Stebbins & Cohen 1995, Pounds et al. 1997, Lips 1998, 1999), in Australia (Laurance et al. 1996) and in Europe (Blab & Vogel 1999). It is well documented, particularly for Western Europe, that once common species have now become rare and live in isolated populations (Honegger 1978, Terhivuo 1981, Blab et al. 1984, Thielcke et al. 1991). In Poland, the dynamics of amphibian declines have not been so well documented as in West European countries. Nevertheless, in some areas this decline was well documented (Juszczyk 1987, Berger 2000, Rafinski & Tabasz 2001, Glowacinski & Rafinski 2003). For example, in Niepolomnice Forest, during twenty years, in the 70s and 80s of twentieth century, the number of amphibians was reduced by 90%, from 2000 to 150–300 individuals per one hectare (Glowacinski & Witkowski 1970, Witkowski 1978, Glowacinski 2003). Similarly, in agricultural landscape of Wielkopolska (Western Poland) during about ten years in the late 60s and early 70s the number of amphibians was reduced from 300 to dozen or so individuals per one hectare (Berger 1987, Rybacki & Berger 1997). Also in protected natural areas, population

17 páginas, 4 figuras, 4 tables et al.., The newts Triturus vulgaris and Triturus montandoni are sister species that exhibit contrasting levels of intraspecific morphological variation. Triturus vulgaris has a broad Eurasiatic distribution encompassing both formerly glaciated and unglaciated areas and shows substantial morphological differentiation in the southern part of its range, while T. montandoni, confined to the Carpathians, is morphologically uniform. We analysed sequence variation of two mtDNA fragments of the total length of c . 1850 bp in 285 individuals of both species collected from 103 localities. Phylogenetic analysis of 200 unique haplotypes defined 12 major clades, their age estimated at c . 4.5–1.0 million years (Myr). Most of the older clades were found in the southern part of the range, and also in central Europe, mainly in Romania. The distribution of mtDNA clades points to the existence of several glacial refugia, located in the Caucasus region, Anatolia, the Balkan Peninsula, Italy, and more to the north in central Europe. The concordance between mtDNA based phylogeny and the distribution of T. vulgaris subspecies was weak. Triturus montandoni haplotypes did not form a monophyletic group. Instead they were found in six clades, in five of them mixed with T. vulgaris haplotypes, most likely as a result of past or ongoing hybridization and multiple introgression of mtDNA from T. vulgaris to T. montandoni. Patterns of sequence variation within clades suggested long-term demographic stability in the southern groups, moderate and relatively old demographic growth in the populations inhabiting central Europe, and high growth in some of the groups that colonized northern parts of Europe after the last glacial maximum., The work was supported by grants 6 PO4C 027 20 from the Polish State Committee for Scientific Research, BW/IZ/15/2003 from the Jagiellonian University, B1725 from the Ministry of Science, Technology & Development of Republic of Serbia, DAPTF Seed Grant 2003 and Biod-Iberia under the European Commission Human Potential Program.

Female newts of the genus Triturus deposit and wrap their eggs individually in the submerged leaves of aquatic macrophytes. Although this behaviour has previously been described, the different elements of the oviposition process have not been fully characterized nor any attempt made to quantify the behavioural elements. The study examined the oviposition behaviour of the two similarly sized species, Triturus helveticus and T. vulgaris on a standardized substrate macrophyte, Rarippa nasturtium-aquaticum. Continuous focal sampling was used to develop a baseline of discrete behavioural elements enabling quantification and comparison of oviposition behaviour between the two species. The results showed that the same pattern of elements was followed for each egg laid and the same key elements of the process were present in each newt species. Although these are broadly similar in size, there were striking differences in certain aspects of the oviposition sequence between the two species. Key findings were that leaf sniffing and leaf flexing and a measure of the duration of ovipositing were all significantly greater in females of T. helveticus and females of T. vulgaris laid significantly more eggs than those of T. helveticus in a standard observation period. The work presented here defines a baseline ethogram and shows how it can be used to reveal quantifiable differences in closely related species. This demonstrates its value in furthering our understanding of oviposition - a key aspect of female behaviour currently understudied in Triturus behavioural ecology, despite its intrinsic interest and value in understanding recruitment and maintenance of populations.

The patterns of ontogenetic and interspecific variation of morphological integration (the relationships and correlation patterns of functionally and developmentally related morphological traits) in facultative paedomorphic species of two European newts (Triturus vulgaris and T. alpestris) were examined. The degree of morphological integration differed among ontogenetic stages. Variation in the level of morphological integration of cranium and postcranial skeleton during ontogeny of paedomorphic newts had the same pattern in both analysed species. The lowest level of cranium morphological integration characterises the larvae and the juveniles. Individuals that follow alternative life-history path (paedomorphs) remain at a relatively low level of morphological integration, while integration highly increased in metamorphosed adult individuals. Limb skeleton also showed a lower level of integration in paedomorphs in comparison with metamorphosed individuals. The hypothesis of morphological integration was confirmed for all stages of T. vulgaris, while the same hypothesis was confirmed only for larval and paedomorphic stages of T. alpestris. In T. vulgaris, metamorphosis changes the pattern of correlation among the cranial traits, while in T. alpestris, the patterns of phenotypic correlation among the cranial traits remain substantially similar for all analysed ontogenetic stages.

Cranial asymmetry was analyzed at different ontogenetic stages of two paedomorphic newt species (Triturus vulgaris and T. alpestris). Attention was focused on fluctuating asymmetry (FA), a measure of developmental stability. The analysis of cranial asymmetry in facultatively paedomorphic populations showed that during ontogeny the FA remains similar or even increases, regardless of the ontogenetic pathway. Paedomorphs and metamorphosed adult individuals did not show any considerable differences in FA. The observed variations in FA among analyzed cranial traits, indicate that developmental precision appear to be more trait specific, dependent on stage and degree of development, and variable during ontogeny.

At the population level, male smooth newts (Triturus vulgaris) have a marked bias for left turning during spermatophore transfer behaviour. In a much more basal species of the genus, the Alpine newt, less than 50% of individuals show a significant left‐ or right‐side preference during courtship, whereas no lateral bias is found at population level. To verify whether the smooth newt's lateralised behaviour is a recent (apomorphic) acquisition, the degree of lateralisation during courtship displays occurring in another relatively more basal species (although less basal than T. alpestris), the Italian newt (T. italicus) was investigated. In the latter species, the analysis of the temporal structure of the sequences showed that males significantly utilised the same side during a single courtship sequence. However, 31% of the Italian newts showed a significant left‐ and 46% a right‐side preference. The presence of lateralisation in two relatively ‘primitive’ species (Alpine and Italian newt) at indivi...

The smooth and the Montandon's newts (Triturus vulgaris and T. montandoni) are genetically similar sister species with highly divergent male secondary sexual traits involved in complex courtship behaviour. Their parapatric ranges overlap at moderate elevations in the Carpathian Mountains where they hybridize readily. Here we present a detailed study of genetic and morphological variation in populations from the area of sympatry. Analysis of variation at seven nuclear markers, mtDNA and male sexual secondary traits was complemented with an ecological survey of breeding sites characteristics. Extensive hybridization was revealed with back-cross individuals similar to either parental species predominating among hybrids. The hybrid zone exhibited a mosaic pattern: the genetic composition of the populations was correlated only weakly with their geographical position. No association with habitat type was found. Departures from Hardy-Weinberg proportions, significant linkage disequilibria and bimodal distribution of genotypes suggest strongly that assortative mating is an important factor shaping the genetic composition of hybrid populations. The pattern of cytonuclear disequilibria did not indicate much asymmetry in interspecific matings. Changes in the frequency of nuclear markers were highly concordant, whereas mtDNA showed much wider bidirectional introgression with 14% excess of T. montandoni haplotype. We argue that the mosaic structure of the newt hybrid zone results mainly from stochastic processes related to extinction and recolonization. Microgeographical differences in mtDNA introgression are explained by historical range shifts. Since morphologically intermediate males were underrepresented when compared to hybrid males identified by genetic markers, sexual selection acting against the morphological intermediates is implied. We discuss the implications of these findings in the context of reinforcement of prezygotic isolation in newts.

Individuals of the Efes population of Triturus vulgaris were found to be significantly smaller than other populations of the nominate subspecies in Turkey. This difference had been found previously and thus seems to be constant over the years. Comparison was made with a population from Manisa, which is only 110 km away from Efes, but is separated by the Bozdaglar Mountains up to 2159 m high. Males in particular differ significantly in various morphometric characters, whereas females were found to be quite similar. The question of whether the difference between the two populations can be attributed to environmental factors or may be due to genetic isolation is discussed. Some external characters such as the form of the crest and the tail tip were shown not to be constant over the years and are thus not useful for taxonomic analysis.

Adult Triturus newts show spatial and temporal variation in sex ratio at the aquatic breeding site, to the extent that contrasting scenarios on the evolution of mating systems appear to be supported. I collected data for the five western European species (Triturus alpestris, Triturus cristatus, Triturus helveticus, Triturus marmoratus, and Triturus vulgaris) over 500 ponds and 27 yr in two areas in France, to test the hypothesis that the phenology of pond presence is independent of gender. Approximately equal numbers of males and females were found. However, in T. marmoratus males outnumbered females, which could be explained by a proportion of females skipping annual breeding opportunities. In the hybrid T. cristatus × T. marmoratus, females were twice as numerous as males, in accordance with Haldane's rule. A trend was observed for a male-biased sex ratio at the start of the aquatic season (late winter–early spring) and for a female bias toward the end of the aquatic season (early summer), sugg...

Paedomorphosis, the presence of ancestral larval and juvenile traits that occur at the descendent adult stage, is an evolutionary phenomenon that shaped morphological evolution in many vertebrate lineages, including tailed amphibians. Among salamandrid species, paedomorphic and metamorphic phenotypes can be observed within single populations (facultative paedomorphosis). Despite wide interest in facultative paedomorphosis and polymorphism produced by heterochronic changes (heterochronic polymorphism), the studies that investigate intraspecific morphological variation in facultative paedomorphic species are largely missing. By quantifying the cranium size and development (bone development and remodeling), we investigated the variation at multiple levels (i.e., between sexes, populations and species) of two facultatively paedomorphic European newt species: the alpine and the smooth newt. The pattern of variation between paedomorphs (individuals keeping larval traits at the adult stage) and metamorphs (metamorphosed adult individuals) varied between species and among populations within a single species. The patterns of variation in size and skull formation appear to be more uniform in the alpine than in the smooth newt, indicating that developmental constraints differed between species (more pronounced in alpine than in smooth newt). Our study shows that the cranial skeleton provides detailed insight in the pattern of variation and divergence in heterochronic polymorphism within and between species and open new questions related to heterochronic polymorphism and evolution of cranial skeleton. Serbian Ministry of Education and Science {[}173043]; SyntheSys {[}NL-TAF 3082]; Naturalis Temminck fellowship; F. R. S.-FNRS {[}J.0008.13]; Fonds Speciaux de la Recherche grant from the University of Liege {[}C-13/03]

The diurnal movement patterns of Triturus vulgaris, Triturus cristatus, Pelobates fuscus, Bufo bufo, Rana temporaria, and Rana arvalis were investigated during five breeding seasons (1994–1998). Two main questions were addressed: (1) What is the probability of an individual amphibian getting killed when crossing the road? and (2) What fraction of the amphibian populations gets killed by traffic? The rate of movement of 203 adult amphibians was recorded. Information on traffic loads was provided, and mortality risk was calculated depending on traffic loads and movement rate. The probability of getting killed ranged from 0.34 to 0.61 when crossing a road with a traffic load of 3207 vehicles/day, and from 0.89 to 0.98 when crossing a motorway. The number of amphibians killed on the road was estimated by systematic counts. Population sizes were estimated for all ponds within 250 m of the relevant highway stretch. Results indicate that about 10% of the adult population of P. fuscus and brown frogs ( R. temporaria and R. arvalis ) were killed annually by traffic at this site.

Meristic characteristics of Triturus vulgaris meridionalis were measured for 48 males and 38 females from the Mediterranean part of Slovenia. T. v. meridionalis is highly dimorphic in all measured characters, probably as the result of different selective forces acting on each sex. The mean snout-vent lengths were significantly larger in females, also females had wider heads and longer trunks. Males had longer heads and tails.

A cross-sectional analysis using different ontogenetic stages (larvae, juveniles, paedotypic, and metamorphic adults) of the smooth newt, Triturus vulgaris, and the alpine newt, T.alpestris, revealed a broad spectrum of perennibranchiation influences on cranial ontogeny in European newts, more pronounced than previously thought. These influences included marked variation in ossification levels, pronounced morphometric variability of many cranial elements, and considerable skull shape changes in the transition from larvae to the adult stage. In comparison with metamorphosed individuals, paedotypic newts had a higher level of variability in both individual cranial traits and cranial shape changes. Sexual size difference of the skull traits was mostly negligible, especially in comparison to the influence of paedogenesis. The main changes in cranial shape of the European newts occurred during metamorphosis. Cranial morphological organization in the majority of examined paedotypes corresponds to cranial organization at late larval stages prior to metamorphosis or at the onset of metamorphosis.

Morphometric data from Fennoscandian populations of the crested newt Triturus cristatus and the smooth newt Triturus vulgaris were analysed for the presence of sexual size and shape dimorphism. The data sets included nine body-related and nine head-related measurements and were examined with univariate, bivariate and multivariate methods. Sexual dimorphism was demonstrated in both species. The separation of specimens was highly related to sex. Although the expression of sexual dimorphism differed between the two species, some patterns were shared. These are discussed in terms of evolution of intersexual dimorphism according to models of ecology, fecundity and sexual selection. In multivariate analyses, sexual dimorphism was restricted to body-related variables such as standard length and distance of extremities (with high values for females), contrasting against cloaca and limb-related characters (with high values for males). In both species, the ‘distance of extremities’ measure (i.e. trunk length) was one of the strongest sexually dimorphic traits. No evidence of sexual dimorphism in head morphology was found. The results are interpreted as primarily concordant with theories on fecundity selection. For example, it has been suggested that females with larger trunk volumes increase their reproductive capacity. The fact that males had longer extremities, in relation to other characters measured, could be attributed to sexual selection. Long limbs in male newts may be beneficial for courtship performance. Since head-related characters did not show any patterns of sexual dimorphism, no evidence was found to suggest that male and female crested and smooth newts have adapted to different feeding strategies.

Identification of hybrids is important for the study of introgression between related species, but can be difficult when morphological differences between parental species are small. In the case of the newts Triturus vulgaris and T. helveticus, males are readily identifiable during the breeding season when secondary sexual characters are highly developed, but female dimorphism is always much less. Male hybrids with intermediate characters are therefore more likely to be detected than female ones. RAPD (random amplified polymorphic DNA) analysis of three putative newt hybrids and examples of the two parent species T. vulgaris and T. helveticus confirmed hybrid status in all three cases. The maternal parents of each hybrid were identified by amplification of mitochondrial cytochrome b and ATPase genes, including partial sequencing of the latter. One hybrid had a T. vulgaris mother while the other two had T. helveticus mothers. The PCR-based methods therefore provided a quick and simple approach for identifying both hybrid status and parentage in crosses between these two urodele species. The RAPD technique should also prove useful for the identification of larvae, which are morphologically indistinguishable in T. vulgaris and T. helveticus.

The breeding site characteristics of the smooth newt (Triturus vulgaris) and the common frog (Rana temporaria) have been investigated in the Republic of Ireland and in Northern Ireland. A total of 278 waterbodies and their surrounding terrestrial habitats were examined in 60 National Grid 10-km squares across the island: 33 habitat parameters were recorded. Discriminant function analyses were calculated which correctly classified 88.46% and 87.5% of the sites for the newt and frog, respectively. These analyses identified the terrestrial and aquatic habitat variables which were important in discriminating between the sites which were used and unused by each of the species. Terrestrial habitat factors, particularly the availability of terrestrial refugia, were found to be especially important in determining the suitability of the breeding sites for both species.

The fate of dewponds, the only substantive wetland habitat on the chalk Downs of southern England, was monitored over an area of 150 km 2 between 1977 and 1996 together with changes in use by the five species of amphibians that inhabit them. Despite a proactive pond restoration programme there was an overall net loss of seven pools (21% of the initial number of 33) by 1996, although a higher proportion and absolute number of surviving ponds were in good condition in 1996 (58%, 15 ponds) compared with 1977 (24%, eight ponds). Anurans (common frogs Rana temporaria and toads Bufo bufo ) were more widespread on the Downs in 1996 compared with 1977, probably because they colonised new ponds effectively, whereas urodeles (smooth newts Triturus vulgaris , palmate newts T. helveticus and crested newts T. cristatus ) all declined over the same period. T. cristatus , a species ceded maximum protection under the European Union Habitats Directive, occurred in nine sites in 1977 but in just three by 1996. Total destruction of ponds was the most common cause of crested newt extinction, but at two sites the species disappeared following the establishment of fish populations. Various indices of amphibian diversity in dewponds are also compared.

Adult and larval body size, age distribution and female fecundity, traits related to fitness in the smooth newt Triturus vulgaris meridionalis, were compared in populations differing in water stability conditions in the area surrounding Rome, near the southern limit of the distribution of this subspecies. Larval body size varied among populations at the end of metamorphosis and was positively related to water stability conditions, which probably led to differences in adult body size. In populations of temporary ponds, age at first breeding was lowered to two years. Traits of female fecundity correlated positively with body size, but not with age. The Italian smooth newt adapted to the unpredictable environment by optimizing reproductive strategies such as the exploitation of the short wet period by means of early deposition of large eggs, which can produce large larvae at metamorphosis.

I mange deler av verden rapporteres det om betydelige nedganger i amfibiepopulasjoner. Det er trukket fram en rekke årsaker til dette. Vannforsuring som følge av sur nedbør kan være en sannsynlig årsak til tilbakegang av amfibier i forsuringsfølsomme områder som deler av Sør- Norge. Feltundersøkelser av padde (Bufo bufo) og liten salamander (Triturus vulgaris), ble kombinert med vannkjemiske undersøkelser og registrering av fiskearter i 15 lokaliteter, hovedsakelig i Mykland, Aust-Agder, i perioden 2010-2011. Hovedområdet for undersøkelsene ble sterkt påvirket av skogbrann i 2008, som forårsaket betydelige terrestriske og akvatiske endringer. Midt i brannområdet ligger en relativt stor lokalitet med liten salamander, Grunnetjenn, hvor også tetthetsestimater av arten ble gjennomført. Totalt ble 11 lokaliteter undersøkt innenfor brannområdet, 3 i nærheten av brannområdet og 1 i Bø i Telemark. Resultatene fra disse undersøkelsene viser i likhet med andre undersøkelser, at lav pH, dårlig pH-bufferkapasitet og tilstedeværelse av fisk [ørret (Salmo trutta), abbor (Perca fluviatilis) og/eller bekkerøye (Salvelinus fontinalis)] er sannsynlige forklaringsfaktorer for tilstedeværelse av amfibier eller ikke. Selv om de undersøkte lokalitetene er relativt ionefattige, ble det også påvist signifikant høyere konsentrasjoner av basekationer som kalsium (Ca2+) i lokaliteter med amfibier, enn lokaliteter uten amfibier. Konsentrasjonene av uorganisk aluminium (Ali) ser ut til å ha en begrenset negativ effekt på amfibieutbredelsen i Mykland. Dette kan trolig forklares med at mye av aluminiumet er bundet opp i det organiske materialet i de relativt humøse lokalitetene, og at Ali-nivåene i dag, etter betydelig nedgang i sur nedbør siden 1980 (75-85 % nedgang i svovelsyre), ikke er høye nok til at dette har effekt på amfibiebestandene i området. Grunnetjenn, med sin betydelige bestand av T. vulgaris, har relativt god vannkvalitet i forhold til de omkringliggende vannforekomstene i brannområdet av Mykland. De ekstreme vannkjemiske forhold som ble dokumentert i august 2008, var trolig ikke så dramatiske i denne lokaliteten, samtidig med at hovedpopulasjonene av liten salamander trolig ikke lengre befant seg i innsjøen under de mest ekstreme vannkjemiske forhold. Allerede i 2009, ett år etter brannen, var vannkvaliteten i Grunnetjenn relativt bra, og betydelige mengder av liten salamander ble påvist. Størrelsen til Grunnetjenn (62 940 m2) gjør den til en relativt unik salamanderlokalitet i Norge. In many parts of the world there are reports of significant declines in amphibian populations. A number of reasons for the declines exist. Water acidification caused by acid rain, is a likely cause of decline of amphibians in acid sensitive areas, as in parts of southern Norway. Field surveys of toad (Bufo bufo) and smooth newt (Triturus vulgaris), was combined with water chemistry surveys and registration of fish species in 15 sites, mainly in Mykland, Aust- Agder, in the period 2010-2011. The main area of the investigation was severely affected by a wildfire in 2008, with significant terrestrial and aquatic changes. Within the wildfire area, there is a relatively large site with newts, Lake Grunnetjenn, where the density estimates of the species was conducted. A total of 11 sites were examined within the wildfire area, 3 near the wildfire area, and 1 in Bø in Telemark. The results of these studies show, in agreement with earlier studies, that low pH and poor pH buffering capacity and presence of fish [trout (Salmo trutta), perch (Perca fluviatilis) and / or brook trout (Salvelinus fontinalis)] are likely explanatory factors for the presence of amphibians or not. Although the studied lakes and ponds have very low ionic strength, significantly higher concentrations of base cations, as calcium (Ca2+), were present in localities with amphibians, compared with those without amphibians. The concentration of inorganic aluminum (Ali) appears to have a limited negative effect on the amphibian distribution in Mykland. This is probably explained by the fact that much of the aluminum is bound up in the organic matter in the relatively humic localities, and the fact that the Alilevels today, after considerable reduction in acid rain since 1980 (75-85% decrease in sulfuric acid), is not high enough to have an effect on amphibian populations in the area. Lake Grunnetjenn, with its substantial population of T. vulgaris, has relatively good water quality in relation to other investigated lakes within the wildfire area. Accordingly, the extreme water chemistry documented in August 2008, was probably less dramatic in this locality compared with that documented in others water bodies within the area. In addition, the major population of newts has probably undergone metamorphosis to adult individuals and thus not present in the lake under this water chemical episode. Already in 2009, one year after the fire, the water quality in Grunnetjenn was relatively good, and significant amounts of newts were discovered. The large size (62 940 m2) of Lake Grunnetjenn makes it a relatively unique salamander locality in Norway.

The changes of length and mass of smooth newts (Triturus vulgaris) were investigated during the aquatic phase of their lives in a small pond of Croatian capital Zagreb. During their aquatic phase from March 19th to June 1st 1994 the ecological conditions in the pond were also checked regularly each week. The changes of tail lengths were the most significant in the changes of totallengths in both sexes. However, while males became slightly longer (from 8,47+0,53 cm to 8,85+0,54 cm, p>0.50) and didn't change their mass (from 2,09+0,14 g to 2,06+0,22 g, p>0.50), females became significantly shorter (from 8,50+0,71 cm to 7,30+0,43 cm, p, Vodenjaci su vrlo slabo istraženi pripadnici vodene faune u Hrvatskoj. Na mnogim mjestima njihov je opstanak i bitno ugrožen čovjekovim aktivnostima, kao što je i vjerojatno uništenje endemične podvrste Triturus vulgaris schreiberi u Bokanjačkome blatu. U svijetu su istraživanja naravno razvijenija, ali još postoje mnoge nepoznanice glede razvoja i ponašanja malih vodenjaka (Triturus vulgaris), te njihovih geografskih razlika. Zbog toga je provedeno ovo istraživanje promjena u njihovoj vodenoj fazi u Vrančevoj bari istočno od Jaruna, u kojoj od posljednjeg presušivanja g. 1992. nema riba, kao ozbiljnih predatora vodenjaka. Od 19. ožujka do 1. lipnja 1994. svaki tjedan, ukupno 11 puta, obavljana su ekološka uzrokovanja u ovoj bari, koja su pokazala tipične nagle i velike oscilacije fizikalnih, kemijskih i bioloških parametara. Mužjaci vodenjaka kroz ovo su razdoblje nešto povećali svoju dužinu (od 8,47+0,53 cm do 8,85+0,54 cm, pO.50) i zadržali masu (od 2,09+0,14 g do 2,06+0,22 g, pO.50), dok su ženke u oba ova pokazatelja znatno izgubile (od 8,50+0.71 cm, do 7,30+0,43 cm, pO.85 i od 2,03+0,31 g do 1, 61+0,25 g, pO.75). Glavni su razlozi za to, uz uobičajene morfološke promjene pred povratak u terestrijalnu fazu, gubitak tvari i energije za proizvodnju i polaganje jaja, a moguće i asinkrona ovipozicija, poznata u ovih životinja. Ličinke malih vodenjaka vrlo su brzo rasle (p 01), zbog nužnosti završetka transformacije prije ljetnog isušivanja ili nastanka nepovoljnih ekoloških uvjeta u bari.

The distribution of smooth and palmate newts (Triturus vulgaris and Triturus helveticus) may be related to water quality. This study compared the larval growth and feeding behaviour of both species under sublethal levels of aluminium and low pH. The growth of both species was inhibited to a similar degree under acidic conditions with aluminium toxicity dependent upon both low pH and developmental stage. The two species were differentially affected by low pH in terms of feeding behaviour. T. vulgaris larvae took significantly longer to snap at food under low pH than the apparently acid-tolerant T. helveticus. Aluminium had no significant effect on the feeding behaviour of either species.

The process of labyrinth determination has been studied in three urodelean and seven anuran species by means of homoplastic transplantation of ear region epidermis, defined as the piece of epidermal layer containing the material of the prospective ear vesicle (labyrinth rudiment). The ear region epidermis was grafted onto the abdominal wall of embryos of the same developmental stage. The earliest stage of operation resulting in ectopic ear vesicle formation was determined, suggesting the appearance of organ-specific properties in the ear ectoderm. These properties were enhanced in the further course of development, as indicated by the frequency of ear vesicle formation and by the volume and degree of complexity that the vesicles reached. The data obtained allowed us to arrange the species studied in a sequence, ranging from most Ranidae and Bufo viridis, in which organ-specific properties appear earlier and are most strongly expressed, to Triturus vulgaris in which their expression is least pronounced. Comparison of properties of the material giving rise to the ear vesicle or to several other ectodermal derivatives led to the conclusion that species-specific differences in determination of different ectodermal rudiments are due to species specific properties of the whole ectoderm. These differences appear to be determined by an evolutionary shift of the beginning of gastrulation towards later cleavage cycles.

SUMMARY 1. Larvae of the smooth newt, Triturus vulgaris, were exposed to four concentrations of ammonium nitrate in artificial pond water (50, 100, 200 and 500 mg 1-−1) under controlled laboratory conditions. 2. Larvae exposed to a 50 mg 1-−1 solution of ammonium nitrate showed no significant difference to control larvae in feeding rate, mass at metamorphosis or time to metamorphosis. However, larvae exposed to 200 or 500 mg 1-−1 ammonium nitrate, for a single period of 24, 48 or 72 h, were significantly smaller than controls at metamorphosis. Larvae exposed to 100 mg 1-−1 had a significantly higher feeding rate than those reared under control conditions or those exposed to 200 or 500 mg 1-−1 ammonium nitrate, but this was not reflected in their size at metamorphosis, which was not significantly different from the controls. Larval survival remained high in all trials. 3. In separate trials, Daphnia, used as a food source for the newt larvae, were exposed to the same series of ammonium nitrate concentrations. Daphnia behaviour was affected by exposure to 200 and 500 mg 1-−1 ammonium nitrate, and in both cases animals were significantly more likely to be found at the top of the water column than those exposed to 50 or 100 mg 1-−1 ammonium nitrate or the control medium.

Abstract Fishes and newts may play similar roles at the same trophic level in freshwater lakes and ponds. Although a great deal is known about the predatory and competitive impact of fish on most freshwater groups, very little is known about fish-newt interactions. In the present work we have studied the influence of a fish population on the distribution and structure of a Triturus vulgaris population. The roach, Rutilus rutilus (L.), in a small forest lake were eliminated experimentally and were reintroduced after six years. Newts appeared in the lake and showed a rapid population increase after the elimination of fish. After the reintroduction offish, the recruitment of young newts virtually ceased and the population decreased. The most probable explanation is that fish prey upon newt larvae, this being supported by our field and laboratory results. Access to water bodies without significant predators and competitors is thus of vital importance for newt populations.

Denne rapporten beskriver arbeidet med å kartlegge og overvåke forekomsten av småsala-mander, Triturus vulgaris, og storsalamander, Triturus cristatus, i Lier kommune i Buskerud i regi av Norsk institutt for naturforskning. Alle kjente eksisterende ynglelokaliteter i Lier kommu-ne som har eller har hatt ynglende bestander av små- eller storsalamander er beskrevet i rap-porten. Videre gir rapporten en beskrivelse av metoder og innsamlingsinnsats. Det er siden begynnelsen av 1990-tallet registrert 54 ynglelokaliteter for små- og/eller storsa-lamander. Det er 24 lokaliteter med kun småsalamander og 30 med både små- og storsala-mander. Av de 30 kjente lokalitetene med storsalamander er det en lokalitet med usikker be-standsstatus pga. delvis igjenfylling med påfølgende gjengroing og en lokalitet hvor storsala-mander ikke lenger er registrert. I rapporten blir 7 lokaliteter beskrevet litt mer detaljert. Det er to lokaliteter som ikke har yng-lende bestand av små- og eller storsalamander, det er 4 med både små- og storsalamander og det er en lokalitet med tidligere forekomst av begge arter. Lahelldammen har den største sala-manderbestanden av lokalitetene som er nærmere beskrevet. Denne bestanden er trolig i stor grad isolert fra de andre pga. veger med stor trafikk. De tre andre lokaliteten har små til mid-dels store bestander av salamander. © Norsk institutt for naturforskning. Publikasjonen kan siteres fritt med kildeangivelse.