Nature Research Centre

Caryophyllidean tapeworms (Cestoda) are widespread parasites of suckers (Catostomidae) in North America, but their phylogenetic relationships remain poorly understood. This study presents molecular data on species of the recently established genus Pseudoglaridacris Oros, Uhrovič et Scholz, 2018. The type species, P. laruei (Lamont 1921), a very common parasite of the white sucker Catostomus commersonii (Catostomidae) in North America, is characterised both molecularly and morphologically based on recently collected, properly fixed specimens from the type host (C. commersonii) and four species of redhorse (Moxostoma spp.), including new host and geographical records from Canada and the United States. Pseudoglaridacris laruei differs from other species in the genus by its size, being the largest species (body length up to 12.7 mm), a high number of testes (62–119) and very few (0–6) postovarian vitelline follicles. Mackiewiczus etowanum from Hypentelium etowanum and Mackiewiczus rarus from Moxostoma poecilurum in Alabama are nomina nuda. The taxonomic status of P. confusa (Hunter 1929), which occurs in ictiobines, and of P. oligorchis (Haderlie 1953), which is most probably a junior synonym of P. laruei with a reduced number of testes, is also discussed, based on molecular data indicating the presence of a putative new species from ictiobines that has not yet been described.

Abstract Once nearly eradicated from Europe, grey wolves ( Canis lupus ) have recently undergone a remarkable demographic recovery, but their long-term survival remains precarious. By analyzing 1,001 genomes, we uncover a mosaic of distinct evolutionary lineages, not a single recovering population. Northern populations exhibit Asian wolf ancestry, while southern populations preserve ancient Holocene lineages, with dog introgression varying by region. Isolated wolves from the Scandinavian, Italian, and Iberian peninsulas harbored particularly high levels of inbreeding and fixed deleterious mutations. Signatures of genome erosion were widespread across Europe, with many populations falling well short of the minimum size recommended for long-term survival. Our study reveals the complex tapestry of wolf ancestry and variation across Europe, which calls for nuanced, regional conservation plans founded in genetic monitoring.

Sarcocystis is a genus of heteroxenous, globally distributed apicomplexan parasites found in reptiles, birds, and mammals. Typically, sarcocysts develop in muscles of intermediate hosts, and oocysts sporulate in intestines of definitive hosts. The parasite's life cycle is based on prey-predator relationships and usually involves two distinct host species. However, some Sarcocystis spp. can complete their full development within a single host species. Brown rats (Rattus norvegicus) are invasive, synanthropic, highly adaptable rodents that are true omnivores and opportunistic feeders. Therefore, it is possible that they can act as definitive hosts of Sarcocystis parasites. This study provides the first comprehensive assessment of Sarcocystis protists in brown rat intestinal samples under natural conditions, combining microscopy and molecular analyses. Of 27 brown rats investigated, 25.9% (7/27) of animals harbored oocysts/sporocysts of Sarcocystis spp. Based on nested PCR and sequencing of four genetic loci (18S rRNA, 28S rRNA, ITS1, and cox1), 59.3% of samples were positive for Sarcocystis spp. Parasites identified were genetically similar to Sarcocystis spp. using bird-bird, bird-Carnivora, rodent-Carnivora, or ungulate-Carnivora as their intermediate-definitive hosts. The present study suggests that synanthropic rodents may facilitate cross-ecosystem transmission of these parasites, increasing infection pressure on livestock, companion animals, and wildlife in human-dominated environments. Future molecular and dietary ecological studies are needed to assess the role of synanthropic and opportunistic hosts, such as the brown rat, in the transmission of Sarcocystis spp.

This study estimates the levels of chemical contamination and the responses of biochemical and cytogenetic biomarkers in Unio pictorum from the Nemunas River after a large-scale fire at a tire storage and processing warehouse (in October 2019), as well as after the subsequent discharge of partially cleaned water used for firefighting. The impact of firefighting water (FW) on the River Nemunas ecosystem was assessed. Elevated levels of trace metals (Pb, Cu, Co, Cr, Al, Zn) in U. pictorum mussels collected downstream from the wastewater treatment plant (WTP) discharger were measured in the first year after the accident. Genotoxic aberrations in gill cells were significantly more frequent in mussels collected downstream of the WTP discharger, along with higher frequencies of cytotoxic damage and changes in acetylcholinesterase activity. PAH metabolite concentrations, including naphthalene (Nap) and benzo(a)pyrene (B(α)P), were also elevated in haemolymph in U. pictorum gathered downstream from the discharger, but differences were not statistically significant. The total sum of 16 PAH concentrations in mussels collected in 2021 and 2022 was over 5 times higher than those in 2020, and the profile of accumulated metals shifted, with Ni, Cd, Cr, and Pb concentrations decreasing while Zn increased significantly. Mussel haemolymph in 2021 contained the highest levels of B(α)P-type PAH metabolites, indicating increased oxidative stress and neurotoxic impact. The results of chemical analysis and the values of genotoxic aberrations determined in gill cells of U. pictorum collected in 2021 and 2022 indicate an increase in PAH contamination and geno-cytotoxic impact compared to the results of 2020; these changes might be related to the gradual cancellation of COVID-19 restrictions and restoration of routine activities. The study provided an opportunity to demonstrate the unique response of a less anthropogenically stressed ecosystem to the extreme impact of contamination related to the fire on the tire recycling plant.

Understanding 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.

The species group, including the West African Mimopacha rotundata Hering, 1941 (the type locality is in Senegal), and two Central African M. brunnea Hering, 1941 (the type locality is in Equatorial Guinea) and M. audeoudi Romieux, 1935 (the type locality is in the southern Democratic Republic of the Congo), was reviewed: 1) type specimens of all species were examined, dissected, and illustrated; 2) new collection localities were provided to all species based on additional non-type material; 3) the subspecies M. brunnea fusca Hering, 1941 synonymous to M. brunnea was moved in synonymy with M. audeoudi (syn. n.); 4) two new species were described from Sudan and South Sudan (M. brysoni sp. n.), and Ethiopia (M. bradyi sp. n.). Four species, apart from M. brunnea, were barcoded and used in phylogenetic reconstruction, all had interspecific p-distances above 4%.