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Povzetek: Canopy-forming brown macroalgae (Fucales) offer numerous key ecosystem services in Mediterranean coastal areas. However, anthropogenic pressures and climate change have significantly impacted their habitats, leading to an extensive population decline. Interactions between algae and microbiota are a major ecological aspect, yet they represent a significant knowledge gap. In our baseline study, we describe the diversity and host specificity of the microbiome of two genetically identical but morphologically distinct populations of Gongolaria barbata from anthropogenically impacted northern Adriatic Sea. Our preliminary results showed that the microbiomes of G. barbata exhibited low host specificity, with 75% of the algae-associated amplicon sequence variants (ASVs) being part of the core coastal ecosystem microbiome. However, microbiomes of specific algal parts, ambient seawater, and sediment differed significantly in terms of alpha diversity and composition. In contrast, the holdfast and axis show higher similarity with sediment microbiomes, indicating potential horizontal transmission pathways. Microbiomes associated with deciduous parts of morphologically distinct G. barbata populations showed no difference in alpha diversity and composition. In contrast, higher variation in alpha diversity and lower sequence proportion of shared ASVs were observed in the holdfast and axis of the two distinct populations. Our observational study provides valuable new insights and baseline for future hypothesis-driven research on the interactions between algae and associated microbiota—a knowledge gap that needs to be addressed in the future for better understanding of the ecological and evolutionary dynamics of coastal ecosystems.
Ključne besede: ecosystem services, anthropogenic pressures, microbiome, host specificity, alpha diversity, marine biology, ecology
Objavljeno v DiRROS: 18.04.2025; Ogledov: 207; Prenosov: 162
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Povzetek: Dolomedes may easily be considered to be among the most charismatic spider taxa. Known colloquially as fishing or raft spiders, this clade of dolomedid cursorial hunters is speciose with about 100 valid species names. Most Dolomedes are large spiders that inhabit water bodies across all continents except Antarctica and, interestingly, South America. Dolomedes have captured the attention of researchers and the public alike for their ability to walk on and submerge under water, fish for prey (including small vertebrates), and for their often-bizarre mating behavior that includes examples of male spontaneous death and sexual cannibalism. In this review, we critically evaluate what is known of Dolomedes biology, focusing on their systematics and morphology, ecology, behavior, and conservation. Given their close association with water, Dolomedes may be particularly vulnerable to the impacts of anthropogenic change and provide an important group of indicator species for understanding the effect of pollution, habitat loss and climate change. We outline a roadmap for future studies that, in our view, will consolidate Dolomedes as an ideal model lineage among spiders for addressing a vast array of questions across multiple fields of biology.
Ključne besede: raft spiders, behavioral ecology, diversity, physiology, evolution, conservation, Dolomedidae
Objavljeno v DiRROS: 28.03.2025; Ogledov: 298; Prenosov: 170
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Povzetek: Classical glacial refugia such as the southern European peninsulas were important for species survival during glacial periods and acted as sources of post-glacial colonisation processes. Only recently, some studies have provided evidence for glacial refugia north of the southern European peninsulas. In the present study, we combined species distribution models (SDMs) with phylogeographic analyses (using mitochondrial DNA = mtDNA) to investigate if the cold-adapted, stenotopic and flightless ground beetle species, Carabus irregularis, survived the Last Glacial Maximum (LGM) in classical and/or other refugia. SDMs (for both a western European and for a Carpathian subgroup) were calculated with MAXENT on the basis of 645 species records to predict current and past distribution patterns. Two mtDNA loci (CO1 and ND5, concatenated sequence length: 1785 bp) were analyzed from 91 C. irregularis specimens to reconstruct the phylogeography of Central and eastern European populations and to estimate divergence times of the given lineages. Strong intra-specific genetic differentiation (inter-clade ΦST values ranged from 0.92 to 0.99) implied long-term isolation of major clades and subsclades. The high divergence between the nominate subspecies and the Carpathian subspecies C. i. montandoni points to two independent species rather than subspecies (K-2P distance 0.042 ± 0.004; supposed divergence of the maternal lineages dated back 1.6 to 2.5 million years BP) differing not only morphologically but also genetically and ecologically from each other. The SDMs also inferred classical as well as other refugia for C. irregularis, especially north of the Alps, in southeastern Europe and in the Carpathians. The coincidences between the results of both methods confirm the assumption of multiple glacial refugia for the studied species and the usefulness of combining methodological approaches for the understanding of the history of low-dispersal insect species.
Ključne besede: ecology, phylogeny, zoogeograpy
Objavljeno v DiRROS: 12.03.2025; Ogledov: 237; Prenosov: 167
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Povzetek: The lime leaf-miner, Phyllonorycter issikii is an invasive micromoth with an unusually higher number of haplotypes in the invaded area (Europe, Western Siberia) compared to its putative native region (East Asia). The origin of the genetic diversity in the neocolonized region remains unclear. We surveyed over 15 thousand herbarium specimens of lime trees (Tilia spp.) collected across the Palearctic over a period of 252 years (1764–2016) looking for preserved larvae within the archival leaf mines. We found 203 herbarium specimens with leaf mines of Ph. issikii collected in East Asia, one of them dating back to 1830, i.e. 133 years before the description of the species. In contrast, only 22 herbarium specimens collected in the West Palearctic in the last three decades (1987–2015) carried leaf mines. DNA barcoding of archival specimens revealed 32 haplotypes out of which 23 were novel (not known from modern populations) and found exclusively in East Asia. Six haplotypes are shared between both native and invaded areas and only two were responsible for the recent invasion of the Western Palearctic. The remarkable number of newly discovered haplotypes in archival populations supports East Asia as the native region and the source area of invasion.
Ključne besede: ecology, entomology, genetics, next-generation sequencing, zoology, invasive species
Objavljeno v DiRROS: 26.02.2025; Ogledov: 252; Prenosov: 126
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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: 274; Prenosov: 167
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