Triturus Alpestris Research Articles

A revised phylogeny of Alpine newts unravels the evolutionary distinctiveness of the Bosnian alpine newt – Ichthyosaura alpestris reiseri (Werner, 1902)

Abstract The Bosnian alpine newt (Ichthyosaura alpestris reiseri) is endemic to Prokoško Lake (Mt. Vranica, Bosnia & Herzegovina); its evolutionary history is partially clarified and its taxonomic position remains unclear. Due to severe anthropogenic pressures on Mt. Vranica (fish introduction in Prokoško Lake, pollution), it has been assumed that this form of Alpine newt is extinct from the Lake. Nevertheless, some specimens originating from Prokoško Lake are still maintained in captivity in two European zoos and by several private keepers. The main goals of the present study are: (1) to investigate the presence of Alpine newts in the Prokoško Lake and the wider area of Mt. Vranica, (2) to conduct phylogenetic analysis on found specimens of Alpine newts in relation to other Balkan populations. Newts were not registered inside Prokoško Lake but several individuals were found in water bodies surrounding the Lake. Genetic analysis shows that these individuals carry the same haplotype as Alpine newts from a captive population originating from Prokoško Lake. All the Alpine newts originating from mt. Vranica are monophyletic on mtDNA markers, hence form an Evolutionary Significant Unit within I. alpestris that is of specific conservation importance. Results corroborate previous findings concerning the complex pattern of genetic diversity of Alpine newt populations in the Balkans that is poorly understood.

Mitochondrial DNA diversity of the alpine newt (Ichthyosaura alpestris) in the Carpathian Basin: evidence for multiple cryptic lineages associated with Pleistocene refugia

The phylogeography and molecular taxonomy of the Alpine newt, Ichthyosaura alpestris, has been intensively studied in the past. However, previous studies did not include a comprehensive sampling from the Carpathian Basin, possibly a key region in the evolution of the species. We used a 1251 bp long fragment of the mitochondrial genome to infer the species’ evolutionary history in central-eastern Europe by assigning isolated Carpathian Basin populations from 6 regions to previously defined mtDNA lineages. We also revised the morphology-based intraspecific taxonomy of the species in the light of new genetic data. Alpine newt populations from the Carpathian Basin represented two different mitochondrial lineages. The Mátra, Bükk and Zemplén Mts populations can be assigned to the Western lineage of the nominotypical subspecies. Bakony and Őrség populations showed high haplotype diversity and formed a separate clade within the Western lineage, suggesting that the Carpathian Basin might have provided cryptic refugia for Alpine newt populations in their cold-continental forest-steppe landscapes during the younger Pleistocene. Newts from Apuseni Mts were related to the Eastern lineage but formed a distinct clade within this lineage. Considering the morphological and genetic differentiation of the Bakony and Őrség populations, consistent with a long independent evolutionary history, we propose these populations be referred to as Ichthyosaura alpestris bakonyiensis (Dely, 1964). We provide a redescription of this poorly known subspecies.

Mass mortality of unknown etiology in alpine newts (Ichtyosaura alperstris veluchiensis) in an alpine lake in Greece

A mass mortality in alpine newts (Ichthyosaura alpestris veluchiensis) was observed in May/June 2013, in Drakolimni lake on Smolikas Mountain, Northwest Greece. 1300 alpine newts were found dead in two events. In 1998 a similar incident was recorded in the nearby lake of Timfi Mt. Newts of every stage and sex were affected, presenting incoordination and inability to float evenly. Ten animals were submitted for complete pathological examination. Field environmental measurements (water temperature, oxygen saturation, pH, conductance, nitric/phosphate concentration) and samples (water, snow, benthos) were collected for ecotoxicological and quality analysis. Necropsy, microbiology (parasitology, bacteriology, mycology), histopathology, molecular investigations (Ranavirus spp, Batrachochytridium dendrobatidis, Batrachochytridium salamandrivorans), quality and ecotoxicological examinations did not indicate a causative source for the mortality. To the author´s knowledge this is the biggest mortality of unknown etiology reported in free-living alpine newts in Europe.

Alpine Newts (Ichthyosaura alpestris) Avoid Habitats Previously Used by Parasite-Exposed Conspecifics

Many organisms avoid habitats posing risks of parasitism. Parasites are not generally conspicuous, however, which raises the question of what cues individuals use to detect parasitism risk. Here, we provide evidence in alpine newts (Ichthyosaura alpestris) that non-visual cues from parasite-exposed conspecifics inform habitat avoidance. Alpine newts breed in aquatic habitats and occasionally move among adjacent terrestrial habitat during breeding seasons. We completed experiments with newts whereby individuals had access to both habitats, and the aquatic habitats varied in prior occupancy by conspecifics with different histories of exposure to the parasitic skin fungus,Batrachochytrium dendrobatidis(Bd). Continuous filming of newt activity for 2 days provided little evidence that prior use of aquatic habitats by conspecifics, regardless of theirBdexposure history, immediately influenced newt habitat use. However, newts that encountered aquatic habitats used specifically byBd-exposed conspecifics on day 1 spent less time aquatic on day 2, whereas other newts did not alter habitat use. Responses could have been elicited by cues generated byBdstages on the conspecifics or, perhaps more likely, cues emitted by the conspecifics themselves. In either case, these observations suggest that newts use non-visual cues sourced from exposed conspecifics to detectBdrisk and that those cues cause newts to avoid aquatic habitats.Bdmay therefore influence host behavior in early phases of interactions, and possibly before any contact with infectious stages is made, creating potential for non-consumptive effects.

Thermal dependence and individual variation in tonic immobility varies between sympatric amphibians

Tonic immobility (TI) is an important antipredator response employed by prey in the last stages of a predation sequence. Evolution by natural selection assumes consistent individual variation (repeatability) in this trait. In ectotherms, which experience variable body temperatures, TI should be repeatable over a thermal gradient to be targeted by natural selection; however, information on thermal repeatability of this trait is missing. We examined thermal repeatability of TI in juveniles of two sympatric amphibians, smooth (Lissotriton vulgaris) and alpine (Ichthyosaura alpestris) newts. Both species showed disparate TI responses to body temperature variation (13-28°C). While the proportion of TI response was repeatable in both taxa, it increased with body temperature in alpine newts but was temperature independent in smooth newts. Duration of TI decreased with body temperature in both taxa but was only repeatable in smooth newts. Our results suggest that a warming climate may affect population dynamics of sympatric ectotherms through asymmetry in thermal reaction norms for antipredator responses.

Host contribution to parasite persistence is consistent between parasites and over time, but varies spatially.

Most parasites and pathogens infect multiple hosts, but a great deal of variation exists in the role of those hosts in persistence of infection. Understanding which hosts are most important in maintaining parasites can provide a clearer target for infection control. Recently developed empirical and theoretical approaches provide a way to quantify the relative contribution of hosts within a community and place them in a multi-host framework to better direct control efforts. Amphibians provide a framework for better understanding multi-host-multi-parasite dynamics. Two well-studied amphibian parasites, Batrachochytrium dendrobatidis (Bd) and Ranavirus, infect multiple host species and exhibit a great deal of heterogeneity in how they affect hosts. We used these two parasites and a community of five amphibian species to investigate the relative importance of hosts in parasite persistence, and how any patterns varied spatially and temporally. At two sites (Lake Ercina and Lake Lloroza in the Picos de Europa National Park, Spain) we collected data on the prevalence and shedding rate of parasite infection for both Bd and Ranavirus, and the abundance of each species' life stages. We used these data to parameterize a recently developed modeling framework, which was used to quantify the relative contribution of each host to the community reproductive number, R0 . By comparing each host-category over time and between sites we were able to identify consistencies in which host was responsible for the maintenance of these two parasites. Within a site one species consistently contributed the most to the persistence of both parasites. This consistency did not transfer between sites, the maintenance host species being different for each. At one site (Ercina), life stages of the common midwife toad, Alytes obstetricans, acted as the maintenance host for both Bd and Ranavirus. In contrast, at the second site, Lloroza, the alpine newt, Ichthyosaura alpestris, fulfilled that role. A single host species was responsible for infection persistence of both parasites at each lake. Attempts to control the infection levels and impacts of multiple parasites can benefit from a community epidemiology approach, and provide clarity on which hosts are the foci of mitigation efforts. However, at a small spatial scale, the target host may vary according to the physical qualities of those sites and the demographics of the host community.

Repeatability and heritability of resting metabolic rate in a long-lived amphibian

Resting metabolic rate (RMR), i.e. spent energy necessary to maintain basic life functions, is a basic component of energy budget in ectotherms. The evolution of RMR through natural selection rests on the premise of its non-zero repeatability and heritability, i.e. consistent variation within individual lifetimes and resemblance between parents and their offspring, respectively. Joint estimates of RMR repeatability and heritability are missing in ectotherms, however, which precludes estimations of the evolutionary potential of this trait. We examined RMR repeatability and heritability in a long-lived ectotherm, the alpine newt (Ichthyosaura alpestris). Individual RMR was repeatable over both six-month (0.28 ± 0.09 [SE]) and five-year (0.16 ± 0.07) periods. While there was no resemblance between parent and offspring RMR (0.21 ± 0.34), the trait showed similarity among offspring within families (broad-sense heritability; 0.25 ± 0.09). Similar repeatability and broad-sense heritability values in parental and offspring generations, respectively, and non-conclusive narrow-sense heritability suggest the contribution of non-additive genetic factors to total phenotypic variance in this trait. We conclude that RMR evolutionary trajectories are shaped by other processes than natural selection in this long-lived ectotherm.

Ontogenetic plasticity in cranial morphology is associated with a change in the food processing behavior in Alpine newts

BackgroundThe feeding apparatus of salamanders consists mainly of the cranium, mandible, teeth, hyobranchial apparatus and the muscles of the cranial region. The morphology of the feeding apparatus in turn determines the boundary conditions for possible food processing (i.e., intraoral mechanical reduction) mechanisms. However, the morphology of the feeding apparatus changes substantially during metamorphosis, prompting the hypothesis that larvae might use a different food processing mechanism than post-metamorphic adults. Salamandrid newts with facultative metamorphosis are suitable for testing this hypothesis as adults with divergent feeding apparatus morphologies often coexist in the same population, share similar body sizes, and feed on overlapping prey spectra.MethodsWe use high-speed videography to quantify the in vivo movements of key anatomical elements during food processing in paedomorphic and metamorphic Alpine newts (Ichthyosaura alpestris). Additionally, we use micro-computed tomography (μCT) to analyze morphological differences in the feeding apparatus of paedomorphic and metamorphic Alpine newts and sort them into late-larval, mid-metamorphic and post-metamorphic morphotypes.ResultsLate-larval, mid-metamorphic and post-metamorphic individuals exhibited clear morphological differences in their feeding apparatus. Regardless of the paedomorphic state being externally evident, paedomorphic specimens can conceal different morphotypes (i.e., late-larval and mid-metamorphic morphotypes). Though feeding on the same prey under the same (aquatic) condition, food processing kinematics differed between late-larval, mid-metamorphic and post-metamorphic morphotypes.ConclusionsThe food processing mechanism in the Alpine newt changes along with morphology of the feeding apparatus during ontogeny, from a mandible-based to a tongue-based processing mechanism as the changing morphology of the mandible prevents chewing and the tongue allows enhanced protraction. These results could indicate that early tetrapods, in analogy to salamanders, may have developed new feeding mechanisms in their aquatic environment and that these functional innovations may have later paved the way for terrestrial feeding mechanisms.

Instant killing of pathogenic chytrid fungi by disposable nitrile gloves prevents disease transmission between amphibians.

To prevent transmission of the pathogenic chytrid fungi Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), hygiene protocols prescribe the single use of disposable gloves for handling amphibians. We discovered that rinse water from nitrile gloves instantly kills 99% of Bd and Bsal zoospores. Transmission experiments using midwife toads (Alytes obstetricans) and Bd, and Alpine newts (Ichthyosaura alpestris) and Bsal, show that the use of the same pair of gloves for 2 subsequent individuals does not result in significant transmission of any chytrid fungus. In contrast, handling infected amphibians bare-handed caused transmission of Bsal in 4 out of 10 replicates, but did not result in transmission of Bd. Based on the manufacturer’s information, high resolution mass spectrometry (HRMS) and colorimetric tests, calcium lactate and calcium nitrate were identified as compounds with antifungal activity against both Bd and Bsal. These findings corroborate the importance of wearing gloves as an important sanitary measure in amphibian disease prevention. If the highly recommended single use of gloves is not possible, handling multiple post-metamorphic amphibians with the same pair of nitrile gloves should still be preferred above bare-handed manipulation.

Individual variation in seasonal acclimation by sympatric amphibians: A climate change perspective

Abstract Many ectotherms modify their phenotype seasonally as a response to variation in abiotic factors. Given the potential of seasonal acclimation to reduce the impact of climate change on the dynamics of ectotherm populations, the adaptive evolution of this reversible plasticity has received much attention. Nevertheless, the key assumption of selection on the magnitude of seasonal acclimation, consistent among‐individual variation (repeatability), remains unexplored. We studied the short‐ (across body temperatures) and long‐term (over two consecutive years) repeatability of seasonal acclimation on standard metabolic rate (SMR) and spontaneous locomotor activity (SLA) in two sympatric newt taxa, Ichthyosaura alpestris and Lissotriton vulgaris. We exposed the newts to various fluctuating thermal regimes over spring and summer and measured SMR and SLA at three body temperatures in each individual over two consecutive years. We quantified seasonal acclimation as difference between summer and spring trait values. We show that individuals of both species vary substantially in their seasonal acclimation responses. Body temperature affected the population means of seasonal acclimation in a quadratic I. alpestris or linear L. vulgaris fashion. Both short‐ and long‐term repeatability of SMR and SLA seasonal acclimation were poor and both species varied in the amount of total variation in the plastic response. Seasonal shifts in environmental temperatures showed high variation between years, but with no apparent trend attributable to local climate change. Our results demonstrate that seasonal SMR and SLA acclimation prevents the establishment of a consistent relationship between individual trait values and environmental gradients, which may limit the adaptive evolution of this plastic response. Disparate thermal dependence patterns and the amount of total variation in seasonal acclimation suggest a species‐specific ability for coping with stochasticity of seasonal variation in the thermal environment. To sum up, information on individual variation and population means measured across ecologically realistic body temperatures is necessary to fully understand the occurrence of seasonal acclimation across taxa and its role in the adaptive capacity to climate change. A free Plain Language Summary can be found within the Supporting Information of this article.

Acoustic enrichment in wildlife passages under railways improves their use by amphibians

Linear transport infrastructure can impact wildlife directly or indirectly, and amphibians are particularly affected. In some cases, mitigation measures – such as tunnels below the linear transport infrastructure – are implemented, but an evaluation of their effectiveness is often lacking, especially for small animals such as amphibians. Few studies have focused on crossing behaviour in underpasses, yet this information may be crucial to improve mitigation measures. In this study, we conducted experiments in three tunnels below a high-speed railway with individually marked amphibians (great crested newt Triturus cristatus, marbled newt Triturus marmoratus, alpine newt Ichthyosaura alpestris, fire salamander Salamandra salamandra, spined toad Bufo spinosus, agile frog Rana dalmatina and edible/pool frog Pelophylax kl. esculentus/lessonae) which were released at the entrance of tunnels varying in length. Behaviours (e.g. completed crossing, U-turn, not moving, and stay) and crossing speed were recorded. R. dalmatina, S. salamandra and T. cristatus (but not B. spinosus) exhibited crossing rate differences between tunnels 21 m and 40 m in length. More individuals performed “complete crossing” through the shorter tunnel. The crossing speed of the S. salamandra and T. cristatus did not differ between the tunnels of different lengths. In a second experiment, we evaluated the effect of acoustic enrichment on the crossing behaviour of one frog and three newt species by broadcasting a soundtrack of mating calls of syntopic anuran species in the tunnels. Pelophylax kl exhibited a large increase in complete crossings and in speed. T. cristatus showed an increase in tunnel complete crossings (but not speed) in one of the acoustically enhanced tunnels. These results indicate that acoustic enrichment can improve the crossing of underpasses. This low cost and easily implementable method could help to inform the design of wildlife passages as mitigation measures for impacted amphibian populations, though more experiments on the effect of tunnel characteristics on amphibian behaviour would be valuable.

Thermal independence of energy management in a tailed amphibian

The relationship between the minimum metabolic requirements (standard metabolic rate, SMR) and energy costs of non-mandatory physiological functions and behaviour is fundamental for understanding species responses to changing environmental conditions. Theory predicts that ectotherms manage their energy budget depending on whether the relationship between SMR and energy available for other tasks is negative (allocation model), neutral (independent model), or positive (performance model). Energy management has received more attention in endotherms than in ectotherms, where metabolic-behavioural relations may be affected by body temperature variation. We examined the predictions of energy management models at four body temperatures in alpine newts, Ichthyosaura alpestris, under laboratory conditions. High SMR reduced the amount of energy dedicated to food digestion and locomotor activity. The maximum metabolic rate for food digestion was positively related to SMR, while its relationship with locomotor activity was inconclusive. Body temperature affected the intercept but not the slope of these relationships. We conclude that (i) newts manage their energy budget according to the allocation model, (ii) energy management is insensitive to body temperature variation, and (iii) determining energy management models using indirect estimates may be misleading. These findings improve our understanding of the eco-evolutionary significance of SMR variation in tailed amphibians and other ectotherms.

Ultrastructural and immunocytochemical studies on the olfactory receptor neurons in the Ichthyosaura alpestris

AbstractMorphological and immunohistochemical studies were conducted on the alpine newt Ichthyosaura alpestris, which is representative of the family Salamandridae. The aim of the study was to determine the differences in olfactory organs structural properties, especially in the olfactory epithelium (OE) of the main olfactory chamber (MOC) and the vomeronasal organ (VNO) between breeding and non‐breeding seasons in this species. A change in environments occurs for alpine newts in the course of the annual cycle because of its aquatic adaptations for reproduction. The results confirmed the variability in the shape and size of olfactory organs between breeding and non‐breeding seasons. The presence of the ovoid cells with microvilli at its apical part was determined in the OE of males and females during breeding season. Giant ORNs, a subtype of ciliated ORNs, were observed only during the newt's non‐breeding season. The presence of the ovoid cells during the terrestrial phase was not determined. Thus, its role might be associated with reproduction.

Key management rules for agricultural alpine newt breeding ponds based on habitat suitability models

The alpine newt, Ichthyosaura alpestris, is very sensitive to habitat destruction and alteration which has led to declining populations across Europe. As this species is protected through the Bern Convention, it is essential to have a comprehensive understanding of its habitat requirements to ensure proper conservation measures. We trained, validated and optimized classification tree models based on data on local aquatic habitat conditions from 125 farmland ponds scattered over Belgium and Luxembourg where the alpine newt commonly occurs. To obtain user-friendly and representative models, data was pre-processed and stratified after which different degrees of pruning were applied for model optimization. In order to check the model’s applicability for management, we predicted alpine newt occurrence with an independent dataset. The most robust and reliable model revealed that fish absence was the major driving factor followed by the thickness of the sludge layer. We found that fish presence established alpine newt absence and that fishless ponds with a sludge layer of 15 cm or more were predicted to host no alpine newts. The latter provides quantitative information for decision makers. Moreover, our results indicated that the amount of sludge could be associated with eutrophication and erosion. Regarding management practices, it is advised to assure the absence of fish and reduce sludge accumulation in ponds designated for the conservation of alpine newts, for example by designing temporary ponds not fed through fish-containing surface waters. Furthermore, we recommend to install buffer strips around a pond to reduce nutrient and soil run-off from the terrestrial environment.

Changes in prey importance and prey niche overlap of sexes during the alpine newt breeding season

Urodeles, including European newts, are usually sexually dimorphic predators. Among newts, the alpine newt has the most pronounced sexual size dimorphism (in favour of females). Gender is a factor that is often associated with intra-specific diet differences. Despite the significant number of dietary studies on the alpine newt, some topics such as the breadth of the trophic niche and its overlap between sexes, or inter-sexual differences in qualitative and quantitative composition of prey remain unresolved. The present study dealing with these questions was conducted at two localities (ponds at an elevation of about 450 m) in the Czech Republic. Newts were captured from the banks during the entire breeding season using a dip net, and the stomach contents were extracted using a stomach flushing technique. Altogether 190 individuals were sampled, and a total of 1,417 prey items were obtained. The available food sources differed over the course of the breeding season, as newts changed the taxa they preyed on. This reflects the ability of newts to switch between several hunting strategies. The overall food niche overlap between the sexes was relatively large (C = 0.761, resp. C = 0.797). Inter-sexual differences were detected at both localities, mainly in the number of prey items consumed from the most important prey categories such as Rana eggs or Isopoda, which were consumed in higher numbers by females. The findings of this study suggest that females are more sensitive to the trade-off between energy intake and expenditure during the breeding season.

A Female Color Ornament Honestly Signals Fecundity

In many species, particularly in ectothermic vertebrates, not only males but also females show bright body colorations. In Alpine newts, Ichthyosaura alpestris, both sexes have colorful orange bellies. This coloration varies in redness (yellowish to dark orange) among individuals, and previous work has shown that courting males preferred females with more orange bellies. Because males in this species are likely to be limited in their mating capacity, selection would favor this preference if this coloration honestly signals female quality. In this study, we investigated whether female belly coloration can predict individual fecundity in which case males might have the chance to fertilize more eggs when they choose to mate with a more ornamented female. We found that more orange females were more fertile than less orange ones. Additionally, we saw that more ornamented females could lay their eggs faster, which means that they ceased egg laying at a similar time as less ornamented females despite the greater number of eggs. This suggests that female color can convey quality advantages in a species with no sex-role reversal much in the same way as male colors can, making female ornaments subject to sexual selection acting directly on them.

Temporal Patterns of Mating Activity in Alpine Newts, Ichthyosaura alpestris

Many amphibians in temperate zones need to time their reproduction in spring carefully, as they need to find a partner, mate, and oviposit in good time to ensure that their offspring metamorphose before the terrestrial phase starts. Therefore, embracing as many mating opportunities as possible, especially early in the mating period, would be advantageous. Here we examine the temporal pattern of mating activity in Alpine Newts, Ichthyosaura alpestris. Males exhibit a highly complex courtship ritual, during which both olfactory and visual signals play a prominent role. The aim of this ritual is a close coordination between the movements of the male and the courted female, a prerequisite for successful spermatophore transfer. We observed mating activity in a large, group aquarium with a natural photoperiod. We recorded the number of mating pairs at every full hour over the course of 4 d, during light and dark conditions. We observed most courtship behavior during light conditions when males were able to guide females properly with visual cues to the spermatophore. Although greatly reduced, we also found some mating activity in dark conditions on the first experimental day; however, mating activity decreased drastically during the following dark phases. Our findings demonstrate that Alpine Newt males that have access to females over several days use mating opportunities predominantly during light conditions, when visual cues can be utilized optimally. Although olfactory cues might be important during mating, our data suggest that visual cues may confer an adaptive advantage during mate choice.

Same but different: aquatic prey capture in paedomorphic and metamorphic Alpine newts

Paedomorphosis describes the retention of larval characters in adult stages and is widespread amongst salamanders. Salamandrid newts exhibit facultative paedomorphosis, where paedomorphic and metamorphic adult forms coexist in the same population. Previous studies have shown that prey capture kinematics do not differ between paedomorphic and metamorphosed ambystomatid salamanders, despite diverging morphology and prey capture performance. It remained unclear, however, whether the stereotypy of prey capture kinematics across morphotypes is restricted to ambystomatids, or can be found in other salamander groups too. Here, we performed biplanar high-speed-recordings of the prey capture behavior in paedomorphic and metamorphic salamandrid newts and only found minor kinematic differences across morphotypes, suggesting that stereotypy across morphotypes is a more general feature within salamanders. We then compared anatomy of skull and hyobranchial skeleton, along with the physiological cross sectional area (PCSA) of the rectus cervicis muscle, the main muscle empowering suction feeding. Besides the overall morphological differences of the feeding apparatus, the PCSA of the rectus cervicis also differs significantly between morphotypes, being twice as large in paedomorphs. Accordingly, paedomorphs can exert more powerful suction strikes, which in turn may be one of the key factors why paedomorphs are more efficient in capturing elusive prey compared to metamorphs.

Herpetofauna of the Podkielecki Landscape Protection Area

Abstract The study was conducted in 2016-2017 in the Podkielecki Landscape Protection Area (area 26,485 ha). It was focused on the occurrence and distribution of amphibians and reptiles, the biology of the selected species and the existing threats. Established in 1995, the Podkielecki Landscape Protection Area surrounds the city of Kielce from the north, east and south-east, and adjoins several other protected areas. It covers the western part of the Świętokrzyskie Mountains (part of the Klonowskie and Masłowskie ranges) and the southern part of the Suchedniów Plateau. The studied area is mostly covered by forest and thicket communities (48.1%) and farmlands (39.9%), followed by built-up areas (7.8%), industrial areas (0.5%), roads and railways (2.7%), and surface water bodies (1%). The protected area is developed mainly on Palaeozoic rocks, including Cambrian and Ordovician sandstones, Silurian and Carboniferous shales, and Devonian marls. Podzolic soils predominate among soils. The largest rivers include Lubrzanka, Czarna Nida, Bobrza and Belnianka. There are no natural lakes within the PLPA limits, and the largest artificial reservoirs include the Cedzyna Reservoir, Morawica Reservoir, Suków Sandpit and two sedimentation reservoirs of the Kielce Power Plant. The area includes 2 nature reserves: Barcza and Sufraganiec. The following amphibian species were recognised during the investigations within the borders of the studied area: alpine newt Ichthyosaura alpestris Laur., great crested newt Triturus cristatus Laur., smooth newt Lissotriton vulgaris L., European fire-bellied toad Bombina bombina L., common spadefoot toad Pelobates fuscus Laur., common toad Bufo bufo L., natterjack toad Epidalea calamita Laur., European green toad Bufotes viridis Laur., European tree frog Hyla arborea L., pool frog Pelophylax lessonae Cam., edible frog Pelophylax esculentus L., marsh frog Pelophylax ridibundus Pall., moor frog Rana arvalis Nilss., and common frog Rana temporaria L. The reptiles were represented by sand lizard Lacerta agilis L., viviparous lizard Zootoca vivipara Jacquin, slow worm Anguis fragilis L., grass snake Natrix natrix L. and common European adder Vipera berus L. The study also included the phenology and breeding biology of the common toad and common frog. The most crucial herpetofauna conservation problems identified here include amphibians killed on roads by vehicles. The study area is intersected by very busy roads, in particular: European route no. E77, national roads nos. 73, 74 and S74, and regional roads nos. 745, 750 and 764. For this reason, future road reconstruction projects should consider the assembly of various crossing roads for wildlife, particularly on the 600 m long section of national road no. 74 near Cedzyna Reservoir. Other threats include illegal waste dumping, pollution of surface waters, fire setting, overgrowing and desiccation of small water bodies. © IOŚ-PIB

The influence of habitat on olfactory organ structure in selected species of salamanders (Salamandridae, Caudata)

Morphological observations (LM, TEM, SEM) of olfactory organs were conducted on three representatives of the family Salamandridae which differ in post-metamorphic habitat: the terrestrial fire salamander Salamandra salamandra, the semiaquatic alpine newt Ichthyosaura alpestris and the semiaquatic Himalayan newt Tylototriton verrucosus which exhibit increasing specialization towards life in water. We demonstrated variability in proportional size and shape of the main olfactory chamber (MOC), as well as in the degree of development of the vomeronasal organ (VNO) among the three species. In the fire salamander, the olfactory sensory epithelium was distributed throughout the MOC, while in the alpine and Himalayan newt the olfactory sensory epithelium was organized in strips. The presence of two types of olfactory receptor neurons (ciliated receptor neurons, microvillar receptor neurons) was confirmed in olfactory organs of all examined species. For the first time in amphibians, a subtype of ciliated receptor neuron – the giant neuron (rod-shape neuron), was detected in the MOC of all three salamandrids. The olfactory epithelium also consists of ciliated supporting cells and secretory supporting cells. The presence of goblet cells, mucociliary epithelial cells and squamous epithelial cells was demonstrated in the olfactory organs of all examined species. Our results indicate that the olfactory organs of salamandrids may differ in size, shape and distribution of olfactory epithelium depending on habitat type during the post-metamorphic stages of ontogeny.