12/31/2023 0 Comments Nebela tincta protistsrotunda (Penard 1890), describe three new species: N. collaris ( Ehrenberg 1848) Kosakyan et Gomaa, change N. We redefine Nebela tincta (Leidy) Kosakyan et Lara and N. We therefore revise the taxonomy of the group. We show here that small variations in test morphology that have been often overlooked by traditional taxonomy correspond to distinct haplotypes. Our goals were (1) to clarify the taxonomy and the phylogenetic relationships within this group, and (2) to evaluate if individual genotypes corresponded to specific morphotypes and the extent of phenotypic plasticity. We examined the relationship between morphological and genetic diversity within this species complex by combined analyses of light microscopy imaging and Cytochrome Oxidase Subunit 1(COI) sequences obtained from the same individual amoeba cells. The taxonomic validity of characters used to define species within this group is debated and causes confusion in studies of biogeography, and applications in palaeoecology. Nebela tincta–collaris–bohemica (Arcellinida) is a species complex of small to medium-sized (ca.100 μm) testate amoebae common in peat bogs and forest soils. Les polyphénols ont également été identifiés comme un facteur explicatif important de la structure des communautés microbiennes, montrant ainsi leurs effets potentiels sur les microorganismes des sphaignes.Species identification by means of morphology is often problematic in protists. Ainsi, les communautés microbiennes des sphaignes apparaissent comme un outil intéressant quant au suivi in situ des changements climatiques. They are small (mostly 20200 mroughly the size of pollen grains), abun-dant (e.g., 103104 individuals g1 dry weight peat), and diverse (about 2000. Les analyses par redondance ont révélé que la structure des communautés microbiennes variait entre les différents traitements dans les parties supérieures des sphaignes. Testate amoebae are unicellular protists, which are ubiquitous in environments such as lakes, rivers, mosses, and soils, but also occur in estuarine environments (Meisterfeld 2002a, b). La biomasse des amibes à thèque est apparue liée à celle des bactéries et à la biomasse additionnée des autres groupes, suggérant des effets indirects de la température sur les relations trophiques. Une modification de la structure de leur communauté a aussi été mise en évidence. La densité et la biomasse des amibes à thèque ont augmenté dans les parties supérieures des sphaignes. Les relations entre les microorganismes et les facteurs abiotiques (pH, conductivité, température, polyphénols) ont également été analysées. Dans cette étude, l’effet d’un gradient de températures (15, 20 et 25 ☌) sur les microorganismes des sphaignes, incluant différent groupes trophiques (producteurs primaires, décomposeurs, micro-prédateurs), a été testé dans les différentes parties des sphaignes (0 à 3 cm et 3 à 6 cm du capitulum). dynamics and food preferences of the testate amoeba Nebela tincta major-bohemica-collaris. Or, peu d’études portent sur l’influence de la température sur ces communautés. Le rgime alimentaire des thcamoebiens (Protista, Sarcodina). Les microorganismes des sphaignes sont connus comme indicateurs précoces des perturbations environnementales. 245 x 198 m L/W Komado marsh Showa & Tajima Fukushima, 2007 N. Phenolic compounds represented an important explicative factor in microbial assemblages and outlined the potential direct and (or) indirect effects of phenolics on microbial communities. The sensitivity of these assemblages made them interesting indicators of climate change. Redundancy analysis revealed that microbial assemblages differed strongly in Sphagnum upper segments along a temperature gradient in relation to abiotic factors. Genus: Test more or less flask-shaped, with more or less neck (Illustrated Guide, 1985). The biomass of testate amoebae was linked to the biomass of bacteria and to the total biomass of other groups added and, thus, suggests that indirect effects on the food web structure occurred. The density and the biomass of testate amoebae in Sphagnum upper segments increased and their community structure changed in heated treatments. Relationships between microbial communities and abiotic factors (pH, conductivity, temperature, and polyphenols) were also studied. ![]() A microcosm experiment was designed to test the effects of a temperature gradient (15, 20, and 25 ☌) on microbial communities including different trophic groups (primary producers, decomposers, and unicellular predators) in Sphagnum segments (0–3 cm and 3–6 cm of the capitulum). Microbial communities living in Sphagnum are known to constitute early indicators of ecosystem disturbances, but little is known about their response (including their trophic relationships) to climate change.
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