Global biodiversity gradients are generally expected to reflect greater species replacement closer to the equator. However, empirical validation of global biodiversity gradients largely relies on vertebrates, plants, and other less diverse taxa. Here we assess the temporal and spatial dynamics of global arthropod biodiversity dynamics using a beta-diversity framework. Sampling includes 129 sampling sites whereby malaise traps are deployed to monitor temporal changes in arthropod communities. Overall, we encountered more than 150,000 unique barcode index numbers (BINs) (i.e. species proxies). We assess between site differences in community diversity using beta-diversity and the partitioned components of species replacement and richness difference. Global total beta-diversity (dissimilarity) increases with decreasing latitude, greater spatial distance and greater temporal distance. Species replacement and richness difference patterns vary across biogeographic regions. Our findings support long-standing, general expectations of global biodiversity patterns. However, we also show that the underlying processes driving patterns may be regionally linked.

• MeSH
• biodiverzita * MeSH
• časoprostorová analýza MeSH
• členovci * klasifikace   fyziologie   MeSH
• zeměpis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Trilobites are among the most iconic of fossils and formed a prominent component of marine ecosystems during most of their 270-million-year-long history from the early Cambrian period to the end Permian period1. More than 20,000 species have been described to date, with presumed lifestyles ranging from infaunal burrowing to a planktonic life in the water column2. Inferred trophic roles range from detritivores to predators, but all are based on indirect evidence such as body and gut morphology, modes of preservation and attributed feeding traces; no trilobite specimen with internal gut contents has been described3,4. Here we present the complete and fully itemized gut contents of an Ordovician trilobite, Bohemolichas incola, preserved three-dimensionally in a siliceous nodule and visualized by synchrotron microtomography. The tightly packed, almost continuous gut fill comprises partly fragmented calcareous shells indicating high feeding intensity. The lack of dissolution of the shells implies a neutral or alkaline environment along the entire length of the intestine supporting digestive enzymes comparable to those in modern crustaceans or chelicerates. Scavengers burrowing into the trilobite carcase targeted soft tissues below the glabella but avoided the gut, suggesting noxious conditions and possibly ongoing enzymatic activity.

• MeSH
• biologická evoluce MeSH
• členovci * anatomie a histologie   enzymologie   fyziologie   MeSH
• koncentrace vodíkových iontů MeSH
• korýši enzymologie   MeSH
• střeva * chemie   enzymologie   metabolismus   MeSH
• synchrotrony MeSH
• vodní organismy enzymologie   fyziologie   MeSH
• zkameněliny * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Extracellular vesicles are thought to facilitate pathogen transmission from arthropods to humans and other animals. Here, we reveal that pathogen spreading from arthropods to the mammalian host is multifaceted. Extracellular vesicles from Ixodes scapularis enable tick feeding and promote infection of the mildly virulent rickettsial agent Anaplasma phagocytophilum through the SNARE proteins Vamp33 and Synaptobrevin 2 and dendritic epidermal T cells. However, extracellular vesicles from the tick Dermacentor andersoni mitigate microbial spreading caused by the lethal pathogen Francisella tularensis. Collectively, we establish that tick extracellular vesicles foster distinct outcomes of bacterial infection and assist in vector feeding by acting on skin immunity. Thus, the biology of arthropods should be taken into consideration when developing strategies to control vector-borne diseases.

• MeSH
• Anaplasma phagocytophilum patogenita   MeSH
• bakteriální infekce imunologie   metabolismus   MeSH
• buněčné linie MeSH
• členovci metabolismus   mikrobiologie   fyziologie   MeSH
• Dermacentor metabolismus   mikrobiologie   fyziologie   MeSH
• extracelulární vezikuly metabolismus   ultrastruktura   MeSH
• Francisella tularensis patogenita   MeSH
• genová ontologie MeSH
• intravitální mikroskopie MeSH
• klíšťata metabolismus   mikrobiologie   MeSH
• klíště metabolismus   mikrobiologie   fyziologie   MeSH
• kůže imunologie   mikrobiologie   parazitologie   MeSH
• lidé MeSH
• membránový protein 2 asociovaný s vezikuly metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• proteiny R-SNARE metabolismus   MeSH
• proteomika MeSH
• T-lymfocyty metabolismus   MeSH
• tandemová hmotnostní spektrometrie MeSH
• transmisní elektronová mikroskopie MeSH
• zánět imunologie   metabolismus   parazitologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• membránový protein 2 asociovaný s vezikuly MeSH
• proteiny R-SNARE MeSH

An integrative approach employing molecular, morphological and geographical data were applied to species delimitation among Deuteraphorura congeners occupying caves of the Western Carpathian Mts. A new species of Deuteraphorura from the Western Carpathians is described. D. muranensis sp. nov. belongs among species with 4 pso at the hind margin of the head and possesses highly troglomorphic features. It is conspicuous with its distinctly elongated claws and long, hair-like body chaetae. The status of the new species was confirmed by DNA barcoding based on the mitochondrial COI marker. Populations of D. kratochvili (Nosek, 1963), the most widespread species, were studied in detail. Both ABGD and PTP analyses brought results congruent with geography, i.e. the molecular and geographic distance of the populations were positively correlated. However, some molecular separation based on pairwise distance and the number of substitutions was indicated within two of the studied populations. Despite the indistinct morphological differences, the tested populations were well isolated both geographically and genetically, which indicates that each studied population may represent a cryptic species. The troglomorphy of cave Collembola at the northernmost border of the distribution of cave-adapted species in the Europe is discussed. It is clear that the level of troglomorphy is closely associated with conditions of the microhabitat occupied by the individual subterranean species. The results of our study enhance the importance of the Western Carpathians regarding the diversity pattern of obligate cave species in Europe.

• MeSH
• členovci anatomie a histologie   klasifikace   genetika   fyziologie   MeSH
• ekosystém MeSH
• fyziologická adaptace MeSH
• jeskyně * MeSH
• respirační komplex IV genetika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH
• Slovenská republika MeSH
• Názvy látek
• respirační komplex IV MeSH

Research on canopy arthropods has progressed from species inventories to the study of their interactions and networks, enhancing our understanding of how hyper-diverse communities are maintained. Previous studies often focused on sampling individual tree species, individual trees or their parts. We argue that such selective sampling is not ideal when analyzing interaction network structure, and may lead to erroneous conclusions. We developed practical and reproducible sampling guidelines for the plot-based analysis of arthropod interaction networks in forest canopies. Our sampling protocol focused on insect herbivores (leaf-chewing insect larvae, miners and gallers) and non-flying invertebrate predators (spiders and ants). We quantitatively sampled the focal arthropods from felled trees, or from trees accessed by canopy cranes or cherry pickers in 53 0.1 ha forest plots in five biogeographic regions, comprising 6,280 trees in total. All three methods required a similar sampling effort and provided good foliage accessibility. Furthermore, we compared interaction networks derived from plot-based data to interaction networks derived from simulated non-plot-based data focusing either on common tree species or a representative selection of tree families. All types of non-plot-based data showed highly biased network structure towards higher connectance, higher web asymmetry, and higher nestedness temperature when compared with plot-based data. Furthermore, some types of non-plot-based data showed biased diversity of the associated herbivore species and specificity of their interactions. Plot-based sampling thus appears to be the most rigorous approach for reconstructing realistic, quantitative plant-arthropod interaction networks that are comparable across sites and regions. Studies of plant interactions have greatly benefited from a plot-based approach and we argue that studies of arthropod interactions would benefit in the same way. We conclude that plot-based studies on canopy arthropods would yield important insights into the processes of interaction network assembly and dynamics, which could be maximised via a coordinated network of plot-based study sites.

• MeSH
• členovci fyziologie   MeSH
• interakce hostitele a parazita * MeSH
• larva fyziologie   MeSH
• lesy MeSH
• rostliny parazitologie   MeSH
• stromy parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

In the terrestrial environment, mercury (Hg) contamination can be originated from different inorganic and metal-organic sources, redistributed and transformed in soils. In the present study, the effects of contaminated food with environmentally relevant concentrations of Hg were evaluated in the soil-dwelling invertebrate Folsomia candida. Changes in growth rate and Hg bioaccumulation levels were observed at different concentrations of Hg in food, which can be complementary for data already available for reproduction and survival from standardized protocols. Collembolan growth was recorded every two days, and their growth rate along with a Von Bertalanffy's growth curve were derived showing that growth was dependent on Hg food concentration. Also, the final length of animals reflected the Hg concentration in food, with differences in all treatments comparing to non-exposed organisms. Toxicokinetic patterns from different Hg concentrations in food were not significantly different during the uptake phase, but differences were found in the depuration phase. Combining the two approaches, collembolans seem to invest their energy for depuration processes, neglecting other vital processes, such as growth. Also, contaminated food avoidance possibly occurred, thus decreasing their feeding and contaminant intake. Therefore, growth tests in collembolans can act as complementary tools to bioaccumulation and reproductive assays, towards a mechanistic understanding of how organisms use their energy upon contamination. Changes in growth rate, even at low and environmentally relevant concentrations, could be a warning signal when occurring in species with key roles in ecosystems. Also, this study highlights the importance of these complementary tests for a better and complete approach to risk assessment studies.

• Klíčová slova
• Bioaccumulation, Contaminated food, Folsomia candida, Mercury, Von Bertalanffy's growth curve,
• MeSH
• biotest MeSH
• členovci fyziologie   MeSH
• dietární expozice MeSH
• hodnocení rizik MeSH
• látky znečišťující půdu toxicita   MeSH
• monitorování životního prostředí MeSH
• rtuť toxicita   MeSH
• růst účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• látky znečišťující půdu MeSH
• rtuť MeSH

Present study focused on how the presence of decaying wood affects soil environment including its biota. The study was carried out in the montane spruce forest, disturbed by wind and bark beetles in Trojmezná Mt. of the Bohemian Forest in the Czech Republic. According to the results, presence of decomposing wood influenced soil environment in terms of its chemical properties by increasing soil pH and total carbon content significantly in soil below the trunks compared with soil from further distance. Decomposing wood did not affect total density and species richness of Collembola, but it had a significant influence on species composition and some species were more abundant in soil right below the trunks whereas others preferred soil environment further from them. Finally, significant relations, both positive and negative, were recorded between some Collembola species and ammonium. Thus, this substance might play a role of a volatile attractant in soil environment.

• Klíčová slova
• Ammonium content, Collembola, Community data, Decay, Decomposing wood, Saprotrophic fungi,
• MeSH
• členovci fyziologie   MeSH
• dřevo chemie   MeSH
• houby MeSH
• lesy MeSH
• monitorování životního prostředí * MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• smrk MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• půda MeSH

The aim of this study was to assess the effect of major cations (Ca2+, Mg2+, Na+, K+, and H+) on cadmium toxicity to the springtail Folsomia candida. Survival of the animals was determined after seven days exposure to different cadmium concentrations in an inert sand-solution medium, in different experimental setups with modification of the cation concentrations. Among the cations tested, Ca2+ and Mg2+ had protective effects on the toxicity of cadmium to the springtails while Na+, K+, and H+ showed less competition with free cadmium ions for binding to the uptake sites of the collembolans. Toxicity predicted with a biotic ligand model agreed well with the observed values. Calculated conditional binding constants and the fraction of biotic ligands occupied by cadmium to show 50% effects were similar to values reported in the literature. The results emphasize the important role of solution chemistry in determining metal toxicity to soil invertebrates.

• Klíčová slova
• Bioavailability, Conditional binding constant, Metal, Soil, Springtail, Survival,
• MeSH
• biologická dostupnost MeSH
• biologické modely * MeSH
• členovci účinky léků   fyziologie   MeSH
• kadmium toxicita   MeSH
• kationty farmakokinetika   MeSH
• látky znečišťující půdu toxicita   MeSH
• půda chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kadmium MeSH
• kationty MeSH
• látky znečišťující půdu MeSH
• půda MeSH

BACKGROUND: Ectomycorrhizal fungi (ECM) play a central role in nutrient cycling in boreal and temperate forests, but their role in the soil food web remains little understood. One of the groups assumed to live as specialised mycorrhizal feeders are Protura, but experimental and field evidence is lacking. We used a combination of three methods to test if Protura are specialized mycorrhizal feeders and compared their trophic niche with other soil invertebrates. Using pulse labelling of young beech and ash seedlings we analysed the incorporation of 13C and 15N into Acerentomon gallicum. In addition, individuals of Protura from temperate forests were collected for the analysis of neutral lipid fatty acids and natural variations in stable isotope ratios. RESULTS: Pulse labelling showed rapid incorporation of root-derived 13C, but no incorporation of root-derived 15N into A. gallicum. The transfer of 13C from lateral roots to ectomycorrhizal root tips was high, while it was low for 15N. Neutral lipid fatty acid (NLFA) analysis showed high amounts of bacterial marker (16:1ω7) and plant marker (16:0 and 18:1ω9) fatty acids but not of the fungal membrane lipid 18:2ω6,9 in A. gallicum. Natural variations in stable isotope ratios in Protura from a number of temperate forests were distinct from those of the great majority of other soil invertebrates, but remarkably similar to those of sporocarps of ECM fungi. CONCLUSIONS: Using three in situ methods, stable isotope labelling, neutral lipid fatty acid analysis and natural variations of stable isotope ratios, we showed that Protura predominantly feed on mycorrhizal hyphae via sucking up hyphal cytoplasm. Predominant feeding on ectomycorrhizal mycelia by Protura is an exception; the limited consumption of ECM by other soil invertebrates may contribute to carbon sequestration in temperate and boreal forests.

• Klíčová slova
• Acerentomon, Carbon, Carbon sequestration, Mycorrhiza, Nitrogen, Nutrition biology, Pulse labelling, Rhizosphere, Stable isotopes, Temperate forests,
• MeSH
• členovci fyziologie   MeSH
• izotopy dusíku analýza   MeSH
• izotopy uhlíku analýza   MeSH
• lesy MeSH
• mykorhiza * chemie   MeSH
• potravní řetězec * MeSH
• půdní mikrobiologie MeSH
• stravovací zvyklosti MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Německo MeSH
• Názvy látek
• Carbon-13 MeSH Prohlížeč
• izotopy dusíku MeSH
• izotopy uhlíku MeSH
• Nitrogen-15 MeSH Prohlížeč

The climatic variability hypothesis was applied to the thermal tolerance of edaphic and cave Collembola occupying contrasting environments. Collembola belonged to four categories - trogloxene, subtroglophile, eutroglophile and troglobiont - with a different degree of affinity to subterranean habitats. Altogether, specimens of 17 species were exposed to a one-hour laboratory survival test. The impact of temperature, species and species-temperature interaction on cold and heat survival was statistically significant. There was a decrease trend in cold and heat tolerance from trogloxenes, over subtroglophiles and eutroglophiles to troglobionts. It was shown that obligate cave species, restricted to climatic-stable cave conditions, retain a functional thermal resistance, i.e. the genetically determined ability to tolerate relatively broader temperature ranges. Our results outlined the direct relationship between the thermal tolerances of species and the size of their geographic distributions. It was also observed that cold resistance of Collembola decreased significantly with increasing species body length, indicating that body size plays an important role in temperature tolerances of arthropods inhabiting soil and subterranean habitats.

• Klíčová slova
• Arthropoda, Body size, Cave, Endemic species, Lethal temperature, Survival, Thermal resistance, Troglobiont,
• MeSH
• aklimatizace MeSH
• členovci fyziologie   MeSH
• jeskyně MeSH
• nízká teplota * MeSH
• podnebí MeSH
• tělesná teplota * MeSH
• velikost těla * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH