1. The microstructure of scales varies in four lizard speciesAnamarija Žagar, Katja Konc, Matej Hočevar, Urban Dajčman, Valentina Perc, Rodrigo Megía-Palma, Miguel A. Carretero, Damjana Drobne, Sara Novak, 2025, izvirni znanstveni članek Povzetek: The microstructure of lizard scales carries a phylogenetic signal in traits, reflecting key adaptations with high functional value. Using scanning electron microscopy, we examined the skin surface of four European Lacertidae species which occur in different habitats, as well as climatic conditions. We sampled Podarcis carbonelli and P. virescens from an oceanic-influenced climate, Zootoca vivipara from a temperate climate, and Gallotia galloti from three climatically distinct sites. In all species, dorsal midbody scales were proximally laminated. However, G. galloti differed from the other species, displaying spiny margins on lamellae, whereas Podarcis species and Z. vivipara had smooth margins. Within G. galloti, spiny microstructures were denser and larger in the northern, humid population compared to the high-elevation and southern, drier populations. These differences highlight the potential functional role of microstructures in skin adaptation to environmental conditions and emphasize their ecological significance in lizard species across climatic variation.
Ključne besede: functional morphology, Lacertidae, morphology, microornamentation, skin
Objavljeno v DiRROS: 09.06.2025; Ogledov: 186; Prenosov: 91
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3. Microclimate variability impacts the coexistence of highland and lowland ectothermsUrban Dajčman, Urtzi Enriquez-Urzelai, Anamarija Žagar, 2025, izvirni znanstveni članek Povzetek: Understanding differences in life-history outcomes under variable abiotic conditions is essential for understanding species coexistence. At middle elevations, a mosaic of available sets of abiotic conditions could allow highland and lowland species of the same ecological guild to overlap. Therefore, these sites are excellent to study the influence of abiotic conditions on life history and, thus, spatial overlap patterns of competing species. To test differences in life-history outcomes, we selected a pair of closely related lacertids, Iberolacerta horvathi and Podarcis muralis, with an overlapping geographical range but a contrasting elevational distribution. To assess how abiotic and biotic factors contribute to the realized niches of both species, we first built dynamic energy budget (DEB) models for each species based on available functional and life-history data. Then, we used a mechanistic modelling framework (NicheMapR) to simulate the microclimatic conditions at 15 study sites across an elevational gradient and performed whole life-cycle simulations for both species to compare egg development times, lifespans, reproductive years, mean yearly basking and foraging times and yearly fecundity in syntopy and allotopy along the elevational gradient. Our simulations show that the variability of abiotic conditions along an elevational gradient affects life-history traits of both species. We found strong effects of species and elevation on life-history outcomes such as longevity, activity and fecundity. We also observed the effects of syntopy/allotopy on egg development times, activity and reproductive output. In addition, we found a significant interplay between elevation and species impacting fecundity where occupying higher elevation habitats resulted in a more pronounced reduction in fecundity in P. muralis. Furthermore, using two different thermal preferences for spring and summer, we show that some physiological and reproductive traits change with seasonal changes in thermal preferences. Based on our simulations, we conclude that the intermediate elevations that harbour the majority of syntopic populations exhibit high environmental variability that is likely facilitating species coexistence. Since our model predictions support that the current elevational distribution of the species is not only affected by abiotic factors, this suggests that past historical contingencies might have also played a significant role. Our study provides a framework using mechanistic models to understand current distribution patterns of two interacting species by comparing life-history differences between species based on responses to changing abiotic conditions along an elevation gradient.
Ključne besede: dynamic energy budget, ectotherms, elevation, Lacertidae, life history, microclimate, syntopy
Objavljeno v DiRROS: 10.04.2025; Ogledov: 231; Prenosov: 119
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5. Effects of alpha-cypermethrin and difenoconazole on survival, growth and biomarkers in European green toad tadpoles (Bufotes viridis, Laurenti 1768)Bruno Bekić, Anamarija Žagar, Tatjana Simčič, Branimir Hackenberger Kutuzović, Olga Jovanović Glavaš, 2024, izvirni znanstveni članek Povzetek: In recent decades, the decline of amphibian populations has become more pronounced and accelerated, with one of the contributing factors being the excessive use of pesticides. Alpha-cypermethrin, an insecticide, and difenoconazole, a fungicide, are widely employed pesticides globally. To gain a comprehensive understanding of the acute impact of these two pesticides on amphibians, we used European green toad (Bufotes viridis) tadpoles as our model organisms. We assessed mortality and mass as apical endpoints, and examined physiological biomarkers including electron transport system (ETS) activity, catalase activity, and carbonyl protein content. Tadpoles were exposed to varying concentrations of the two pesticides for 48 hours (0.2-10 µg/L for alpha-cypermethrin; 10-100 µg/L for difenoconazole). Our results indicate that the exposure of tadpoles to these pesticides significantly affected their physiology. Mortality was observed exclusively in tadpoles treated with difenoconazole (LC50 = 100.832 µg/L), while a decrease in mass occurred in tadpoles exposed to both pesticides. No significant differences across treatments were found for total ETS activity, catalase activity, or the presence of protein carbonyls. In conclusion, our findings suggest that alpha-cypermethrin at environmentally relevant concentrations poses a risk to European green toad tadpoles, while the effects of difenoconazole are become patent at higher concentrations than those recorded in natural aquatic environments.
Ključne besede: amphibia, electron transport system, pesticide exposure, toxicology, zoology, ecology
Objavljeno v DiRROS: 07.01.2025; Ogledov: 306; Prenosov: 180
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6. Selection on the vascular-remodeling BMPER gene is associated with altitudinal adaptation in an insular lizardNina Guerra Serén, Catarina Pinho, Rodrigo Megía-Palma, Prem Aguilar, Anamarija Žagar, Pedro Andrade, Miguel A. Carretero, 2024, izvirni znanstveni članek Povzetek: High altitude imposes several extreme constraints on life, such as low oxygen pressure and high levels of ultraviolet radiation, which require specialized adaptations. Many studies have focused on how endothermic vertebrates respond to these challenging environments, but there is still uncertainty on how ectotherms adapt to these conditions. Here, we used whole-genome sequencing of low-altitude (100–600 m) and high-altitude (3,550 m) populations of the wide-ranging Tenerife lizard Gallotia galloti to uncover signatures of selection for altitudinal adaptation. The studied populations show reduced differentiation, sharing similar patterns of genetic variation. Selective sweep mapping suggests that signatures of adaptation to high altitude are not widespread across the genome, clustering in a relatively small number of genomic regions. One of these regions contains BMPER, a gene involved with vascular remodeling, and that has been associated with hypoxia-induced angiogenic response. By genotyping samples across 2 altitudinal transects, we show that allele frequency changes at this locus are not gradual, but rather show a well-defined shift above ca. 1,900 m. Transcript and protein structure analyses on this gene suggest that putative selection likely acts on noncoding variation. These results underline how low oxygen pressure generates the most consistent selective constraint in high-altitude environments, to which vertebrates with vastly contrasting physiological profiles need to adapt in the context of ongoing climate change.
Ključne besede: high altitude, adaptations, ectotherms, whole-genome sequencing, selective sweep, BMPER gene, hypoxia, genomics
Objavljeno v DiRROS: 08.10.2024; Ogledov: 649; Prenosov: 338
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7. Moja, tvoja, naša biodiverzitetaDanilo Bevk, Marjana Hönigsfeld Adamič, 2019, druge monografije in druga zaključena dela Povzetek: Radi imamo dišeč, pisan travnik. Radi imamo jutranjo pesem ptic. Radi imamo žuboreč potok in kačjega pastirja nad njim. Radi imamo…
Zakaj ne bi torej imeli radi biodiverzitete, ki nam vse to omogoča? Zbližajmo se z njo, spoznajmo njene čare! Kajti tisto, kar nam je blizu in kar poznamo, veliko lažje varujemo.
Ključne besede: biološka raznovrstnost
Objavljeno v DiRROS: 04.09.2024; Ogledov: 442; Prenosov: 350
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8. Analysis of subcellular energy metabolism in five Lacertidae lizards across varied environmental conditionsAnamarija Žagar, Urban Dajčman, Rodrigo Megía-Palma, Tatjana Simčič, Frederico Barroso, Senka Baškiera, Miguel A. Carretero, 2024, izvirni znanstveni članek Povzetek: Aerobic respiration is the main energy source for most eukaryotes, and efficient mitochondrial energy transfer greatly influences organismal fitness. To survive environmental changes, cells have evolved to adjust their biochemistry. Thus, measuring energy metabolism at the subcellular level can enhance our understanding of individual performance, population dynamics, and species distribution ranges. We investigated three important metabolic traits at the subcellular level in five lacertid lizard species sampled from different elevations, from sea level up to 2000 m. We examined hemoglobin concentration, two markers of oxidative stress (catalase activity and carbonyl concentration) and maximum rate of metabolic respiration at the subcellular level (potential metabolic activity at the electron transport system). The traits were analysed in laboratory acclimated adult male lizards to investigate the adaptive metabolic responses to the variable environmental conditions at the local sampling sites. Potential metabolic activity at the cellular level was measured at four temperatures – 28 °C, 30 °C, 32 °C and 34 °C – covering the range of preferred body temperatures of the species studied. Hemoglobin content, carbonyl concentration and potential metabolic activity did not differ significantly among species. Interspecific differences were found in the catalase activity, Potential metabolic activity increased with temperature in parallel in all five species. The highest response of the metabolic rate with temperature (Q10) and Arrhenius activation energy (Ea) was recorded in the high-mountain species Iberolacerta monticola.
Ključne besede: physiology, lacertids, aerobic respiration, interspecific variability, hemoglobin, zoology
Objavljeno v DiRROS: 03.09.2024; Ogledov: 517; Prenosov: 1117
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9. Poljudno poročilo rezultatov projekta : Life naturaviva, biodiverziteta - umetnost življenjaAnamarija Žagar, Blaž Koderman, Danilo Bevk, Davorin Tome, Jernej Polajnar, Maja Opalički, 2022, končno poročilo o rezultatih raziskav Povzetek: Kadar koli v družbi vznikne socialni ali naravni problem, se zbere skupina zainteresiranih ljudi, da bi ga rešili ali vsaj oblažili posledice. Z naraščanjem človeške populacije se število težav povečuje vedno hitreje. Podnebne spremembe in kriza biodiverzitete sta naravna problema, ki sta se povzpela na vrh seznama.
Vsi, ki se ukvarjajo s problemom krize biodiverzitete, slej ko prej spoznajo, da je težave bistveno lažje reševati, če jih ljudje razumejo do te mere, da so jih pripravljeni aktivno podpreti. Zato morajo biti ljudje čim bolj izobraženi in dobro obveščeni o problemih / rešitvah — eno izmed pomembnih naravovarstvenih orodij je zato tudi komuniciranje.
Mnogi v Sloveniji so zaskrbljeni zaradi krize biotske raznovrstnosti, veliko jih deluje na področju varstva narave. Manjka pa nam pobud, ki bi se osredotočale na biotsko raznovrstnost kot skupni imenovalec življenja. Vse vrste in naravni procesi znotraj ekosistemov so soodvisni, zato za biotsko raznovrstnost ne moremo skrbeti le z varovanjem določenih območij ali izbranih vrst. Ljudi je treba soočiti z nacionalno (ali celo širšo) vrednostjo biotske raznovrstnosti, če jih želimo odkrito seznaniti s problemom in pričakovati njihovo sodelovanje. Od tod potreba po projektu, ki bi zajel različne dele in ravni biotske raznovrstnosti ter jih predstavil ljudem kot enoten, neprecenljiv naravni pojav. Nekakšna sistematična predstavitev bogastva naše naravne dediščine z jasnim sporočilom, kako pomembno je, da zanjo skrbimo
Objavljeno v DiRROS: 02.09.2024; Ogledov: 519; Prenosov: 3402
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10. Deliverables 4 & 6 : refinement of pesticide risk assessment of amphibians and reptiles based on ecology and biology of wild populationsMarta Biaggini, Miguel A. Carretero, Dan Cogalniceanu, Mathieu Denoël, Christoph Leeb, Valentin Mingo, Gianpaolo Montinaro, Anamarija Žagar, 2024, končno poročilo o rezultatih raziskav Povzetek: Amphibians and reptiles are among the most threatened vertebrate taxa worldwide. About 41% (34%- 51%) of amphibians and 21% (18%-33%) of reptiles are included in the IUCN categories of threatened species (Critically Endangered, Endangered or Vulnerable; IUCN, 2021; Cox et al., 2022). In Europe, nearly a quarter of amphibians and one fifth of reptiles are threatened and a further 17% of amphibians and 13% of reptiles are included among the Near Threatened species (IUCN, 2021). There are multiple reasons why amphibians and reptiles are declining, but habitat loss and degradation, followed by chemical pollution, both mainly attributable to the expansion of intensive agriculture, are commonly indicated among the major causes of herpetofauna decline worldwide as well as in the European region (Gibbons et al., 2000; Collins and Storfer, 2003; Ribeiro et al., 2009; Todd et al., 2010; Böhm et al., 2013, Arntzen et al., 2017).
Ključne besede: reptiles, amphibians, pesticides, risk assessment, environmental protection
Objavljeno v DiRROS: 02.09.2024; Ogledov: 623; Prenosov: 262
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