1,721,239 research outputs found
Annotated checklist of Georgian oribatid mites-II
No full textMurvanidze, Maka, Todria, Nino, Maraun, Mark, Mumladze, Levan (2023): Annotated checklist of Georgian oribatid mites-II. Zootaxa 5227 (1): 50-62, DOI: https://doi.org/10.11646/zootaxa.5227.1.
FIGURE 1 in New taxa and new records of oribatid mites of the family Galumnidae (Acari: Oribatida) from Ecuador
No full textFIGURE 1. Neoctenogalumna longiciliata sp. nov., adult: A—body dorsally; B—body ventrally (gnathosoma and legs not illustrated); C—prodorsum, pteromorph and anterior part of notogaster dorso-laterally; D—notogaster posteriorly. Scale bar 50 Μm.Published as part of Ermilov, Sergey G., Starý, Josef, Sandmann, Dorothee, Marian, Franca & Maraun, Mark, 2013, New taxa and new records of oribatid mites of the family Galumnidae (Acari: Oribatida) from Ecuador, pp. 259-270 in Zootaxa 3700 (2) on page 262, DOI: 10.11646/zootaxa.3700.2.4, http://zenodo.org/record/22012
Top-down control of soil microarthropods - Evidence from a laboratory experiment
No full textPredator-prey interactions are of eminent importance as structuring forces for animal communities. The present study investigates if and how strongly the density of soil microarthropods is controlled by top-down forces, i.e. predation by mesostigmate mites (Mesostigmata, Acari). We set up a laboratory experiment running for ten weeks with undisturbed soil cores taken from the field using two densities of predatory mesostigmate mites: (1) ambient density (control) and (2) increased density (addition of seven Pergamasus septentrionalis and eight Lysigamasus sp. individuals). Increased predator density resulted in a decrease in the density of Oribatida, Collembola and Protura whereas the density of other taxa including Astigmata, Prostigmata and Uropodina was not significantly affected. Additionally, the species number of Oribatida was also not significantly affected. Taxa of Oribatida and Collembola were differently affected by increased predator density. Among Collembola, densities of Poduridae and Sminthuridae were reduced, whereas Entomobryidae were not affected. Among Oribatida, densities of Oppiidae and Suctobelbidae were reduced whereas Desmonomata, Poronota and Tectocepheus were not affected. Grouping of Oribatida into different size classes and into classes differing in sclerotization suggests that smaller mites (200-300 mu m) and mites with less sclerotization were more heavily affected than larger mites and mites with strong sclerotization. The results indicate that predatory mesostigmate mites have the potential to control the density of certain taxa of soil microarthropods. In particular, small and little sclerotized prey is susceptible to predator control indicating that predator defense is an important component of the life history tactics of soil microarthropods, especially of Oribatida. (c) 2008 Elsevier Ltd. All rights reserved
Opening up new niche dimensions: The stoichiometry of soil microarthropods in European beech and Norway spruce forests
No full textNiche theory fundamentally contributed to the understanding of animal diversity. However, in soil, the diversity of animals seems enigmatic since the soil is a rather homogeneous habitat, and soil animals are often generalist feeders. A new approach to understand soil animal diversity is the use of ecological stoichiometry. The elemental composition of animals may explain their occurrence, distribution, and density. This approach has been used before in soil macrofauna, but this study is the first to investigate soil mesofauna. Using inductively coupled plasma optic emission spectrometry (ICP-OES), we analyzed the concentration of a wide range of elements (Al, Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Zn) in 15 soil mite taxa (Oribatida, Mesostigmata) from the litter of two different forest types (beech, spruce) in Central Europe (Germany). Additionally, the concentration of carbon and nitrogen, and their stable isotope ratios (15N/14N, 13C/12C), reflecting their trophic niche, were measured. We hypothesized that (1) stoichiometry differs between mite taxa, (2) stoichiometry of mite taxa occurring in both forest types is not different, and (3) element composition is correlated to trophic level as indicated by 15N/14N ratios. The results showed that stoichiometric niches of soil mite taxa differed considerably indicating that elemental composition is an important niche dimension of soil animal taxa. Further, stoichiometric niches of the studied taxa did not differ significantly between the two forest types. Calcium was negatively correlated with trophic level indicating that taxa incorporating calcium carbonate in their cuticle for defense occupy lower trophic positions in the food web. Furthermore, a positive correlation of phosphorus with trophic level indicated that taxa higher in the food web have higher energetic demand. Overall, the results indicate that ecological stoichiometry of soil animals is a promising tool for understanding their diversity and functioning.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Open-Access-Publikationsfonds 202
Trophic ecology of three marine polychaete species: Evidence from laboratory experiments using stable isotope (15N, 13C), fatty acid (NLFA) analyses, and C and N stoichiometry
No full textMicro- and Macroscale Changes in Density and Diversity of Testate Amoebae of Tropical Montane Rain Forests of Southern Ecuador
No full textWe investigated changes in diversity and density of testate amoebae in epiphytes of trees in tropical montane rain forests of southern Ecuador. Local - microscale [height on tree trunk of 0 (base of tree trunk), 1 and 2 m; TH I, TH II and TH III, respectively] and regional - macroscale (forests at 1000, 2000 and 3000 m) changes were investigated. At the macroscale diversity and density of testate amoebae peaked at 2000 m. At the microscale diversity reached a maximum at TH I, whereas density reached a maximum at TH III. The percentage of empty shells at the macroscale was at a maximum at 2000 m and at the microscale at TH I, whereas the percentage of live cells was at a maximum at 3000 m and at TH III. The diversity of testate amoebae in epiphytes found in the present study was high (113 species). However, only two to nine species were dominant representing 54-85 percent of total living testate amoebae. The results suggest significant variations in density and diversity of testate amoebae at both the micro- and macroscale. However, for testate amoebae density the macroscale appears most important whereas changes in diversity are more pronounced at the microscale.German Research Foundation (DFG) [FOR 402, FOR 816
Dispersal patterns of oribatid mites across habitats and seasons
No full textAbstract Oribatid mites are tiny arthropods that are common in all soils of the world; however, they also occur in microhabitats above the soil such as lichens, mosses, on the bark of trees and in suspended soils. For understanding oribatid mite community structure, it is important to know whether they are dispersal limited. The aim of this study was to investigate the importance of oribatid mite dispersal using Malaise traps to exclude sole passive wind-dispersal. Oribatid mite communities were collected over a 3-year period from five habitat types (coniferous forests, deciduous forests, mixed forests, meadows, bog/heathlands sites) and three seasons (spring, summer, autumn) in Sweden. Mites entered traps either by walking or by phoresy, i.e., by being attached to flying insects. We hypothesized (1) that oribatid mite communities in the traps differ between habitats, indicating habitat-limited dispersal, and (2) that oribatid mite communities differ among seasons suggesting that dispersal varies due to changing environmental conditions such as moisture or resource availability. The majority of the collected species were not typically soil-living species but rather from habitats such as trees, lichens and mosses (e.g., Carabodes labyrinthicus, Cymbaeremaeus cymba, Diapterobates humeralis and Phauloppia lucorum ) indicating that walking into the traps or entering them via phoresy are of greater importance for aboveground than for soil-living species. Overall, oribatid mite communities collected in the traps likely originated from the surrounding local habitat suggesting that long distance dispersal of oribatid mites is scarce. Significant differences among seasons indicate higher dispersal during warm and dry periods of the year. Notably, 16 species of oribatid mites collected in our study were sampled for the first time in Sweden. This study also demonstrates that Malaise traps are a meaningful tool to investigate spatial and temporal patterns of oribatid mite communities.Abstract Oribatid mites are tiny arthropods that are common in all soils of the world; however, they also occur in microhabitats above the soil such as lichens, mosses, on the bark of trees and in suspended soils. For understanding oribatid mite community structure, it is important to know whether they are dispersal limited. The aim of this study was to investigate the importance of oribatid mite dispersal using Malaise traps to exclude sole passive wind-dispersal. Oribatid mite communities were collected over a 3-year period from five habitat types (coniferous forests, deciduous forests, mixed forests, meadows, bog/heathlands sites) and three seasons (spring, summer, autumn) in Sweden. Mites entered traps either by walking or by phoresy, i.e., by being attached to flying insects. We hypothesized (1) that oribatid mite communities in the traps differ between habitats, indicating habitat-limited dispersal, and (2) that oribatid mite communities differ among seasons suggesting that dispersal varies due to changing environmental conditions such as moisture or resource availability. The majority of the collected species were not typically soil-living species but rather from habitats such as trees, lichens and mosses (e.g., Carabodes labyrinthicus, Cymbaeremaeus cymba, Diapterobates humeralis and Phauloppia lucorum ) indicating that walking into the traps or entering them via phoresy are of greater importance for aboveground than for soil-living species. Overall, oribatid mite communities collected in the traps likely originated from the surrounding local habitat suggesting that long distance dispersal of oribatid mites is scarce. Significant differences among seasons indicate higher dispersal during warm and dry periods of the year. Notably, 16 species of oribatid mites collected in our study were sampled for the first time in Sweden. This study also demonstrates that Malaise traps are a meaningful tool to investigate spatial and temporal patterns of oribatid mite communities
Two new species of Schalleria (Acari: Oribatida: Microzetidae) from Ecuador with a key to all species of the genus
No full textTwo new microzetid mite species of the genus Schalleria, Schalleria brevisetosasp. nov. and Schalleria pectinatasp. nov., are described. The morphology of the gnathosoma and the legs is presented in detail for the first time for a species of this genus. An identification key to all known species of Schalleria is provided.German Research Foundation [RU 816
Micro- and Macroscale Changes in Density and Diversity of Testate Amoebae of Tropical Montane Rain Forests of Southern Ecuador
No full textWe investigated changes in diversity and density of testate amoebae in epiphytes of trees in tropical montane rain forests of southern Ecuador. Local - microscale [height on tree trunk of 0 (base of tree trunk), 1 and 2 m; TH I, TH II and TH III, respectively] and regional - macroscale (forests at 1000, 2000 and 3000 m) changes were investigated. At the macroscale diversity and density of testate amoebae peaked at 2000 m. At the microscale diversity reached a maximum at TH I, whereas density reached a maximum at TH III. The percentage of empty shells at the macroscale was at a maximum at 2000 m and at the microscale at TH I, whereas the percentage of live cells was at a maximum at 3000 m and at TH III. The diversity of testate amoebae in epiphytes found in the present study was high (113 species). However, only two to nine species were dominant representing 54-85 percent of total living testate amoebae. The results suggest significant variations in density and diversity of testate amoebae at both the micro- and macroscale. However, for testate amoebae density the macroscale appears most important whereas changes in diversity are more pronounced at the microscale.German Research Foundation (DFG) [FOR 402, FOR 816
Small-scale spatial heterogeneity of stable isotopes signatures (δ15N, δ13C) in Sphagnum sp. transfers to all trophic levels in oribatid mites
No full textSmall-scale heterogeneity is important for understanding soil animal diversity since it may explain their local coexistence. We investigated the heterogeneity within and between three Sphagnum microhabitats (Sphagnum lawn: apical green part, decomposing brown part; submerged Sphagnum) and the heterogeneity of potential consumers (oribatid mites) in two German peatlands (Dubringer Moor, Klockenbruch) using stable isotopes (N-15, C-13). Small-scale heterogeneity of the potential food resource (Sphagnum sp.) in N-15 and C-13 was high. The heterogeneity of N-15 signatures of Sphagnum sp. was transferred to oribatid mite taxa indicating that Sphagnum sp. is their basal food resource. The close relationship between stable isotopes ratios in Sphagnum sp. and oribatid mites on the scale of a few meters furthermore points to the low mobility of mites. When oribatid mites where aggregated into trophic levels, the strongest correlation occurred between N-15 in Sphagnum sp. and oribatid mites of the first trophic level. Oribatid mites spanned 9.1 delta N-15 and 4.4 delta C-13 units in the Dubringer Moor and 9.5 delta N-15 and 4.7 delta C-13 units in the Klockenbruch indicating that they span over about three trophic levels. Three oribatid mite species (Rhysotritia ardua, Hydrozetes lacustris, Pergalumna nervosa) were trophic generalists whereas eleven other species (e.g. Hoplophthiracarus illinoisensis, Hypochthonius rufulus) had rather narrow trophic ranges as indicated by variance in N-15 and C-13 signatures. Isotopic signatures of similar oribatid mites collected in the green and brown parts of the Sphagnum lawn were rather close together suggesting that they use the same food sources. In the Sphagnum lawn, oribatid mites low in the food web were primary decomposers such as Platynothrus peltifer and Nothrus pratensis, whereas Oppiella spp. had high delta N-15 signatures pointing to fungal feeding or predation/scavenging. Limnozetes rugosus and Hydrozetes lacustris had the highest N-15 signatures indicating that these taxa are high in the food web possibly feeding on protozoans and nematodes living in the biofilm on the stems and branches of Sphagnum sp. (C) 2016 Elsevier Ltd. All rights reserved
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