Jan Petružela

Artificial pond construction is widely used in wetland restoration, yet biodiversity outcomes depend strongly on design and subsequent management. We tested how different regimes (grazing, mowing, and no management) influence habitat structure, water conditions, and aquatic macroinvertebrate diversity in newly excavated experimental ponds within an eutrophic wetland in South Moravia (Czechia). Across four focal groups (Mollusca, Odonata, Coleoptera, Heteroptera), we observed rapid colonisation of the newly built ponds. Species richness and densities rose during early development, dropped after drying events, and then partially recovered, indicating repeated “resetting” of communities under fluctuating hydrology. Periodic drying also prevented fish stock establishment. Management significantly affected species composition and both grazed and mowed ponds displayed higher densities (abundances) than controls, but differed only slightly in terms of species richness. The grazed ponds were characterised by high sunlight exposure, reduced reed dominance, and trampling-generated high littoral heterogeneity. These ponds showed highest numbers of taxa adapted to shallow and warm waterbodies, muddy substrate, semiaquatic microhabitats, or newly emerged and disturbed habitats. The mowed ponds promoted dense submergent vegetation, supporting Odonata representation and other taxa requiring aquatic vegetation. The control ponds remained highly shaded by high-grown reed, organic-matter rich, hosting a set of taxa tolerant of low-light, low-oxygen conditions. At the wetland scale, multiple small ponds increased overall diversity through high between-pond heterogeneity. Our results highlight that pond construction alone is insufficient for wetland restoration: follow-up long-term management regimes, especially extensive grazing, can rapidly generate structural heterogeneity and sustain diverse aquatic invertebrate assemblages in eutrophic wetlands.

Parasites are expected to hybridise in similar ways to free‐living organisms, although this may be modified by their reduced genome architecture. Recombinant strains and taxa of hybrid origin can be studied in nature where hosts come into secondary contact. Here we apply genome‐wide analysis to parasites from a contact previously characterised for many individuals using classical markers. The host contact is the European house mouse hybrid zone; the parasites are lung fungus Pneumocystis and gut pinworm Syphacia . The genomic (many loci) and classical (many‐individual) results are broadly consistent in scale and centring of transitions across the host hybrid zone. Whole mitogenome comparisons confirm earlier suggestions that parasite divergence is low compared to their hosts, perhaps due to reduced‐genome stabilising selection. In the recombining genome, we are able to show blocks of the parasite genome of alternating host origin, including one Pneumocystis strain which appears to be an F3+ cross and one recombinant Syphacia strain found over multiple localities. Functional analyses of introgressing genes show enrichment for genes likely important for parasitic lifestyle. Our work confirms that evolutionary models of hybridisation apply equally to hosts and their parasites.

Parasites are expected to hybridise in similar ways to free living organisms, although this may be modified by their reduced genome architecture. Recombinant strains and taxa of hybrid origin can be studied in nature where hosts come into secondary contact. Here we apply genome-wide analysis to parasites from a contact previously characterised for many individuals using classical markers. The host contact is the European house mouse hybrid zone; the parasites are lung fungus Pneumocystis and gut pinworm Syphacia. The multilocus and multi-individual datasets are broadly consistent in scale and centering. Whole mitogenome comparisons confirm earlier suggestions that parasite divergence is low compared to their hosts, perhaps due to reduced genome stabilising selection. In the recombining genome we are able to show blocks of parasite genome of alternating host origin, including one Pneumocystis strain which appears to be an F3+ cross and one recombinant Syphacia strain found over multiple localities. Functional analyses of introgressing genes show enrichment for genes likely important for parasitic lifestyle.

Trichuris spp. is a widespread nematode which parasitizes a wide range of mammalian hosts including rodents, the most diverse mammalian order. However, genetic data on rodent whipworms are still scarce, with only one published whole genome (Trichuris muris) despite an increasing demand for whole genome data. We sequenced the whipworm mitogenomes from seven rodent hosts belonging to three biogeographic regions (Palearctic, Afrotropical, and Indomalayan), including three previously described species: Trichuris cossoni, Trichurisarvicolae, and Trichurismastomysi. We assembled and annotated two complete and five almost complete mitogenomes (lacking only the long non-coding region) and performed comparative genomic and phylogenetic analyses. All the mitogenomes are circular, have the same organisation, and consist of 13 protein-coding, 2 rRNA, and 22 tRNA genes. The phylogenetic analysis supports geographical clustering of whipworm species and indicates that T. mastomysi found in Eastern Africa is able to infect multiple closely related rodent hosts. Our results are informative for species delimitation based on mitochondrial markers and could be further used in studies on phylogeny, phylogeography, and population genetics of rodent whipworms