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Stable isotope analysis reveals habitat-driven dietary niches of Lepus europaeus /
No full textUnderstanding the trophic ecology of the European brown hare (Lepus europaeus) is essential for its conservation in intensifying agricultural landscapes. To explore dietary niches across habitats, sexes, and age groups, we applied stable isotope analysis of carbon (δ13C) and nitrogen (δ15N) in hair samples from 151 hares collected in Lithuania and Poland from 2023 to 2025. δ13C and δ15N values varied significantly by country and habitat, but not by sex or age. Lithuanian hares exhibited lower δ13C values and a wider isotopic niche, reflecting more diverse foraging in heterogeneous habitats. In contrast, Polish hares from uniform orchard landscapes showed higher δ13C enrichment and narrower isotopic ranges, indicating greater dietary specialization on cultivated plants. Temporal variation was minimal, and isotopic overlap among months and years was high. These results suggest that habitat heterogeneity, rather than demographic factors, drives dietary flexibility in L. europaeus. Thus, stable isotope analysis provides a powerful tool for linking agricultural land use with trophic niche breadth in farmland mammals. Promoting mixed cropping systems, permanent vegetation, and structurally diverse habitats could improve food quality and support the recovery of declining hare populations
Comparison of historic and novel data reveals higher contemporary diversity of trematode metacercariae in freshwater fish /
No full textTrematode metacercariae are the most abundant and frequently encountered helminths in freshwater fish. Yet, accurate species identification remains challenging, potentially leading to an underestimation of trematode diversity. Using data from parasitological examinations of 1,030 fish (47 species) collected from diverse freshwater habitats in Lithuania (2022–2024), we assessed the contemporary diversity of trematode metacercariae, host associations, microhabitat preferences, and changes in diversity patterns and transmission dynamics. Through integrated morphological and molecular techniques, we identified metacercariae belonging to 51 species from eight families, more than doubling previously reported diversity (25 species). While trematode family composition remained largely unchanged – the Diplostomidae and Strigeidae remained the most diverse families – notable differences were observed at the species level. Metacercariae of the Echinochasmidae and Echinostomatidae were detected for the first time, while previously reported Clinostomidae were absent. Fish of the Leuciscidae hosted the highest trematode diversity. Host specificity of metacercariae was generally low, with most species being euryxenous. At the microhabitat level, eyes harboured the highest number of species, while muscles showed the highest metacercarial density. Notably, we detected species first genetically characterised in North America (Echinoparyphium sp. 2 and Ichthyocotylurus sp. 2) and species potentially belonging to the genus Neogogatea, previously known only from Asia and North America, highlighting potential invasion risks and suggesting that European trematode diversity remains substantially underestimated. Future efforts should obtain molecular data from correctly identified adult specimens to resolve the identity of species currently identified only to the genus or family level, thereby enabling assessment of their geographical distributions and ecological roles
Molecular evidence of raccoon dog (Nyctereutes procyonoides) as a natural definitive host for several Sarcocystis species /
No full textSarcocystis parasites infect a wide range of animals, including reptiles, birds, and mammals, and have complex two-host prey–predator life cycle. Sarcocysts are mainly found in the muscles of intermediate hosts, and oocysts sporulate in the intestines of the definitive host. The raccoon dog (Nyctereutes procyonoides), native to Asia and invasive in Europe, is a known disease carrier. However, studies on raccoon dogs in the transmission of Sarcocystis are scarce. Between 2019 and 2024, a total of 26 raccoon dog carcasses were collected in Lithuania. The results of a light microscopy examination indicated that 50% of the samples were positive for Sarcocystis spp. sporocysts and sporulated oocysts. Based on nested PCR and sequencing of cox1, 88.5% of the samples were positive for these parasites. Molecular analysis revealed the presence of 11 different Sarcocystis species. Eight species, including S. alces, S. capracanis, S. hjorti, S. iberica, S. linearis, S. morae, S. tenella, and S. venatoria were reported for the first time in raccoon dogs as definitive hosts. The identified Sarcocystis species were linked to intermediate hosts, such as cervids, wild boars, pigs, goats, and sheep. These findings suggest that raccoon dogs play a key role in the spread of Sarcocystis, particularly species infecting cervids
Influence of diallyl disulfide on the properties of biobased antimicrobial vitrimers for microimprint lithography /
No full textoai:gamtc.lt:elaba:232536663This work contributes to the development of sustainable materials by creating biobased photopolymerized vitrimers with antimicrobial, shape-memory, and self-welding capabilities, essential for industries using light-based manufacturing technologies where petroleum-based materials lacking such properties are currently used. In this study, the influence of the amount of diallyl disulfide, which has antimicrobial properties and forms dynamic bonds, on the vitrimeric behavior and antimicrobial activity of biobased vitrimers synthesized from acrylated epoxidized soybean oil, 2-hydroxy-3-phenoxypropyl acrylate, and diallyl disulfide was determined. The addition of 0.35 mol of diallyl disulfide to a resin containing 1 mol of acrylated epoxidized soybean oil and 1 mol of 2-hydroxy-3-phenoxypropyl acrylate was found to reduce resin viscosity by 55%, photocuring rate by 30% and shrinkage to 0%, and increase polymer flexibility by 53%. These polymers exhibited excellent self-welding and shape-memory properties enabled by dynamic disulfide bond exchange. Antimicrobial tests have shown that resins containing more than 0.05 mol of diallyl disulfide, 1 mol of acrylated epoxidized soybean oil, and 1 mol of 2-hydroxy-3-phenoxypropyl acrylate inhibit the bacterial growth of Escherichia coli by more than 97%, Staphylococcus aureus by more than 49%, as well as the fungal growth of Aspergillus flavus by more than 83%, and Aspergillus niger by more than 38% after 1 h of direct contact with the bacterial or fungal suspensions. Micrometer-scale patterns formed using microimprint lithography confirmed the potential of these vitrimers with diallyl disulfide moieties as antimicrobial advanced engineering materials for applications where flexibility and sustainability are required
European pine marten (Martes martes) as natural definitive host of Sarcocystis species in Latvia: Microscopic and molecular analysis /
No full textApicomplexan parasites of the genus Sarcocystis utilize a wide range of vertebrate hosts, including reptiles, birds, and mammals, and follow a complex two-host prey–predator life cycle. Sarcocysts develop within the muscle tissue of intermediate hosts, while oocyst sporulation occurs in the intestines of definitive hosts. Despite their broad host range, the role of Mustelidae predators in the transmission and maintenance of Sarcocystis species remains poorly understood, highlighting the need for targeted studies in this area. In 2023, 20 intestinal samples were collected from European pine martens (Martes martes) in Latvia. Light microscopy revealed sporocysts of Sarcocystis spp. in 70.0% of the samples. Sarcocystis species were identified by using the analysis of obtained cox1 and ITS1 sequences. Using molecular methods, Sarcocystis spp. were confirmed in 85.0% of the samples examined, and co-infections with two or more different parasite species were established in 30.0% samples. We detected eight Sarcocystis species (S. arieticanis, S. bertrami, S. capracanis, S. cruzi, S. entzerothi, S. hjorti, S. morae, and S. truncata) associated with intermediate hosts such as cervids, cattle, sheep, goats, and horses. Additionally, a genetically novel species, Sarcocystis sp. 25MmLV, was detected in a single European pine marten. These findings suggest that European pine martens serve as definitive hosts for multiple Sarcocystis species, particularly those infecting cervids
Collaborating with marine birds to monitor the physical environment within coastal marine protected areas /
No full textAnimal telemetry is maturing into a viable method for observing the ocean as it can be used to monitor both environmental conditions and biological metrics along the movement trajectories of marine animals. As part of the Cormorant Oceanography Project, we have augmented a biologging tag with an external fast response temperature sensor to collect ocean temperature profiles from the backs of foraging marine birds. Cormorants dive between 50 and 250+ times a day to forage for prey so they can provide hard-to-match temporal and spatial coverage of coastal ocean conditions within their foraging areas. We process tag measurements to obtain fundamental oceanographic data (e.g., temperature profiles, bottom soundings, surface current measurements). Together, we have tracked 17 marine bird species (including two Spheniscus penguins spp. and a sea duck), originating from 17 countries and foraging along the edges of all major oceans. Tagged birds’ distribution included 191 MPAs in 26 countries, offering a unique ocean monitoring method to complement more widely used methods
Physiological, biochemical, and genetic reactions of winter wheat to drought Under the influence of plant growth promoting microorganisms and calcium /
No full textImproving wheat drought stress tolerance is a critical and challenging task, and more research is necessary since many parts of the world depend on this crop for food and feed. Our current work is focused on the influence of probiotic microorganisms in combination with calcium salts on the physiological and biochemical metabolic pathways that wheat uses when exposed to drought stress and on the analysis of gene expression levels that contribute to wheat drought tolerance. The research was conducted in the laboratory under controlled conditions, simulating a prolonged drought. Seedlings were treated with different microorganisms (Bacillus subtilis, Lactobacillus paracasei, and some yeast) in 105 CFU/mL concentrations for seed priming and later in the same concentration for seedling spraying. A total of 70 g/m2 CaCO3 or 100 g/m2 CaCl2 was added to the soil before sowing the seeds. Almost all tested treatments improved plant growth and positively affected prolonged drought resistance in winter wheat. Bacillus subtilis, in combination with calcium salts, had the greatest effect on maintaining the relative leaf water content (RWC). The proline, malondialdehyde (MDA), and H2O2 tests proved the significant positive impact of the treatments on the plant’s response at the biochemical level, with growth parameters close to those of irrigated plants, for example, the ones treated with B. subtilis alone or with Ca salts had the lowest H2O2 content, 0.86–0.96 μmol g−1 FW, compared to 3.85 μmol g−1 FW for the Control, along with lower levels of drought-induced gene expression. All the presented results show statistically significant differences (p < 0.05). This study showed that tested microorganisms in combination with calcium salts can activate plants’ defense reactions in response to drought. The practical significance of this study is that these ecological measures can be useful under field conditions
Halotolerance of phytoplankton and invasion success of Nostocalean cyanobacteria under freshwater salinization /
No full textDisturbed ecosystems are particularly susceptible to biological invasions. Increasing freshwater salinization, caused by anthropogenic factors, can alter the phytoplankton community and favour newly arrived halotolerant species. This study investigates the halotolerance of four Nostocalean cyanobacterial species—the native to Europe, Aphanizomenon gracile, and alien Chrysosporum bergii, Cuspidothrix issatschenkoi, and Sphaerospermopsis aphanizomenoides—using monoculture experiments under varying NaCl concentrations. Additionally, we performed two microcosm experiments to explore shifts in biodiversity in freshwater phytoplankton communities sourced from artificial reservoirs and assess their susceptibility to cyanobacterial invasion under salinity stress. Results showed that all Nostocalean cyanobacteria were halotolerant under mild salinities (up to 1 g/L NaCl), with Chrysosporum bergii and Sphaerospermopsis aphanizomenoides demonstrating the most salt tolerance. In the microcosm experiment, changes in community composition were driven by the halotolerance of dominant groups. Water body 1, dominated by Bacillariophytina, reduced its biomass of phytoplankton at high salinity (5 g/L NaCl), while water body 2, dominated by Chlorophytina, remained stable regardless of disturbance. Both cyanobacteria successfully invaded both halotolerant and halosensitive communities, increasing their dominance as salinity rose. Our findings suggest that anthropogenic stressors such as freshwater salinization can alter the phytoplankton community and increase a competitive advantage to certain taxa, including widespread alien cyanobacteria, potentially promoting invasions and bloom formation
Evolution of thermal plasticity in Hymenoscyphus fraxineus during ash dieback expansion in Europe /
No full textThe plasticity of adaptive traits may be critical for population persistence in heterogeneous environments. However, its evolution is rarely investigated in forest pathogens, potentially limiting the accuracy of epidemic risk predictions. Ash dieback is an emblematic example of a forest epidemic caused by an invasive fungal pathogen—Hymenoscyphus fraxineus, which has likely been introduced to Eastern Europe from East Asia. We investigated the plasticity and thermal niche evolution of H. fraxineus during its spread across Europe. We characterized the reaction norms of in vitro mycelial growth and viability of H. fraxineus isolates from five European populations sampled along a latitudinal gradient spanning from Lithuania to Italy. While all populations responded uniformly to temperature decrease, their responses to temperature increase diverged markedly. The growth of H. fraxineus isolates from the northernmost population (Lithuania) was most negatively affected by high temperatures, whereas the southernmost isolates (Italy) showed optimal growth at a higher temperature compared to the other populations. Additionally, the viability of Lithuanian isolates was significantly reduced by higher temperatures compared to that of the other populations. These findings suggest that both growth plasticity and thermal niche have evolved during the pathogen's expansion in Europe, with potentially important implications for predicting and managing future epidemic risks. We further discuss how evolutionary processes may have shaped these phenotypic differences
Sensory pollutants have negative but different effects on nestbox occupancy and breeding performance of a nocturnal raptor across Europe /
No full textAnthropogenic noise and artificial light at night (ALAN) are expanding globally, acting as pervasive sensory pollutants that can disrupt wildlife behaviour and reproduction. While most research has focused on diurnal species, the effects of these pollutants on the ecological response of nocturnal predators remain poorly understood. Using data from nine European countries, we investigated the effects of traffic noise, ALAN, and road proximity on nestbox occupancy and reproduction in the Tawny Owl (Strix aluco), a nocturnal raptor widespread across Europe. Traffic noise consistently reduced both nestbox occupancy and reproductive success regardless of road proximity. ALAN also impaired occupancy and reproduction, but its negative effect on reproduction changed based on the proximity to roads. Interestingly, the negative effect of ALAN was stronger in sites further from roads, but it attenuated in their proximity, where owls' hatching success and brood size moderately improved. This finding suggests that near roads, where prey abundance and availability are also generally high, owls may either find the prey regardless of ALAN or they may exploit it to facilitate hunting and brood provisioning. However, vicinity to roads might enhance mortality by vehicle collisions, which represents one of the greatest threats for the conservation of owls. Our findings highlight that anthropogenic noise and the co-occurrence between ALAN and roads can affect settlement decisions and breeding performance in nocturnal raptors, with potential consequences across the food chain. Mitigating anthropogenic noise and promoting nighttime-lighting systems that minimize owls' presence close to roads will represent valuable actions to improve their conservation