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Candida species are considered the most common opportunistic human fungal pathogen due to the presence of various virulence factors, including its ability to form a biofilm that aids in oral candidiasis. Pediatric patients are more susceptible to oral candidiasis than healthy pediatric because of the factors that encourage Candida oral carriage. This current study aims to isolate, evaluated the antifungal effect on Candida spp. and participated in oral candidiasis of pediatric patients in Sulaymaniyah and Kirkuk city. The study was performed from September 2021 to February 2022 on two groups of pediatrics which including pediatric patients (n=160) and healthy pediatric (n=50) as a control group. Oral swabs were obtained from 210 participants in the Kurdistan Region of Iraq at the Pediatric teaching hospital of the Sulaymaniyah and Kirkuk governorates. To culture the swabs, Sabouraud dextrose agar (SDA) medium was used. HiCrome™ Candida Differential agar used to identify Candida isolated, then depending on the internal transcribed spacer (ITS) region using confirmed polymerase chain reaction. Antifungal sensitivity was done for all C. albicans and non)albicans isolates using five common antifungal disks. Among of the 160 sample of pediatric patient 62 (38.8%) positive for Candida spp. which it is including 17 (27.4 %) and 26 (41.9%), 19 (30.6%) breast feeding, bottle feeding and mixing respectively. While within 50 samples of control group 13 (26%) were positive for Candida spp. which including 2 (15.4%), 9(69.2%), 2(15.4%) of same respectively feeding types. Regarding to the antifungal susceptibility the results showed that C. albicans had higher resistance rates against itraconazole, ketoconazole, and clotrimazole than the non-albicans Candida species However, highly resistant rate were detected in Itraconazole and Ketoconazole with 23.7% and 54.4% respectively, for all Candida species. The Current study concluded that oral candidiasis was more predominant in pediatric patients in compare to healthy pediatric also, and C. albicans is the most prevalent etiologic agent. However, higher rate of sensitivity were detected between Candida species for nystatin, which may suggest as the main treatment for oral Candida infections. [ABSTRACT FROM AUTHOR]

Beavers and their dams, once common in small streams throughout Eurasia and North America, are returning to their original range. Beaver dams are special habitats in the aquatic-terrestrial interface, but their macroinvertebrate fauna is hardly known. This study aims to qualify and quantify the invertebrate fauna of beaver dams, taking into account the maintenance status of the dams. Nine different areas covering the top, middle and base zones of eight maintained and eight abandoned beaver dams were sampled using a specially designed suction device. The invertebrate community of beaver dams proved to be diverse and predominantly rheophilic. Community composition reflects higher flow velocities in streamside habitats; this gradient is more pronounced in maintained than in abandoned dams. Shredders are the most abundant feeding type, but they are less frequent in streamside habitats, in particular in those of maintained dams, where passive filter feeders prevail. Terrestrial/Semiaquatic taxa colonising hygropetric areas were found in streamside habitats especially of abandoned dams. Our results underline that beaver dams provide a wide variety of environmental conditions and habitat types, which enhance biodiversity in small streams and their floodplains. Beaver dams in riverine landscapes should therefore be much more valued in floodplain conservation and management. [ABSTRACT FROM AUTHOR]

Candida species are considered the most common opportunistic human fungal pathogen due to the presence of various virulence factors, including its ability to form a biofilm that aids in oral candidiasis. Pediatric patients are more susceptible to oral candidiasis than healthy pediatric because of the factors that encourage Candida oral carriage. This current study aims to isolate, evaluated the antifungal effect on Candida spp. and participated in oral candidiasis of pediatric patients in Sulaymaniyah and Kirkuk city. The study was performed from September 2021 to February 2022 on two groups of pediatrics which including pediatric patients (n=160) and healthy pediatric (n=50) as a control group. Oral swabs were obtained from 210 participants in the Kurdistan Region of Iraq at the Pediatric teaching hospital of the Sulaymaneyah and Kirkuk governorates. To culture the swabs, Sabouraud dextrose agar (SDA) medium was used. HiCrome™ Candida Differential agar used to identify Candida isolated, then depending on the internal transcribed spacer (ITS) region using confirmed polymerase chain reaction. Antifungal sensitivity was done for all C. albicans and non-albicans isolates using five common antifungal disks. Among of the 160 sample of pediatric patient 62 (38.8%) positive for Candida spp. which it is including 17 (27.4 %) and 26 (41.9%), 19 (30.6%) breast feeding, bottle feeding and mixing respectively. While within 50 samples of control group 13 (26%) were positive for Candida spp. which including 2 (15.4%), 9(69.2%), 2(15.4%) of same respectively feeding types. Regarding to the antifungal susceptibility the results showed that C. albicans had higher resistance rates against itraconazole, ketoconazole, and clotrimazole than the non-albicans Candida species However, highly resistant rate were detected in Itraconazole and Ketoconazole with 23.7% and 54.4% respectively, for all Candida species. The Current study concluded that oral candidiasis was more predominant in pediatric patients in compare to healthy pediatric also, and C. albicans is the most prevalent etiologic agent. However, higher rate of sensitivity were detected between Candida species for nystatin, which may suggest as the main treatment for oral Candida infections.

The current study examined the combined effects of feeding rates and feeding types on the water quality, growth performance, digestive enzymes, blood parameters, and liver antioxidant enzymes of Nile tilapia (Oreochromis niloticus) fingerlings reared under a biofloc system. A 3 × 2 factorial experimental design was used with three feeding rates (2%, 3%, and 4%) and two feeding types (sinking or floating feed), comprising six treatments with three replicates. Fingerlings with an initial body weight of 4.50 ± 0.25 g were stocked in eighteen circular plastic tanks (0.5 m3) at a stocking density of 35 fish per tank fed three times a day at 10:00, 12:00 and 15:00. Starch was added to all treatments as an organic carbon source at a C/N ratio of 10:1. The phytoplankton community was determined to consist of twenty-two species, including individuals from the classes Cyanobacteria, Chlorophyceae, and Bacillariophyta. The most common phytoplankton classes were Chlorophyceae, followed by Cyanobacteria, and fish-fed floating feed at a feeding rate of 2% of total biomass yielded the greatest number of phytoplankton communities. Eight zooplankton species belonging to rotifers and protozoa were identified during this experiment. The highest values of final body weight, weight gain, and specific growth rate were recorded for a fish-fed floating diet with the highest feeding rate (4% of biomass). The highest hepatosomatic index (HIS) was detected in a fish-fed floating diet at a rate of 4% of total biomass. Though fish-fed sinking feed with a 4% biomass feeding rate presented the highest spleen index (SI). The highest significant (P 0.05) on hemoglobin (Hb), hematocrit (Hct), and red blood cells (RBCs). Feeding rate, feed type, and their interactions had no significant impact (P > 0.05) on serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), or albumin, but feeding rates or feed types had an effect (P

The baseline data of radioactivity levels in food is one of the main factors for the assessment of resident's health risk. Gross beta and alpha activity was identified for selected commercial freshwater fish species, including 29 types of fish species by a gas-flow proportional detector. The samples were collected from wholesale markets in Hanoi city, Vietnam. The highest gross alpha activity was recorded in blotched snakehead, a pelagic and carnivorous species, and the lowest one was recorded in common carp, a demersal and omnivorous species. Meanwhile, the gross beta activity was much higher than the gross alpha activity with the highest value of gross beta, observed in Wels catfish, a demersal and carnivorous species, and the lowest one found in Mudskipper a demersal, herbivores species. Regarding feeding types, the gross alpha activity was observed in the order of Alcarnivores > Alomnivores > Alherbivores whereas the gross beta was non-distinction. In terms of living behavior, the gross alpha activity in pelagic species was much higher than that in demersal species (Alpelagic > > Aldemersal) and indifferent for gross beta. There was an insignificant relationship between the trophic level with gross beta and alpha activities in freshwater fish species. The calculated annual effective dose ​​ranged from 0.19 to 1.88 and 0.78 mSv.y−1 on average, being within the limited dose for the public as reported by UNSCEAR in which gross beta activity has a strong correlation with the total annual effective dose. [ABSTRACT FROM AUTHOR]

In this study, x band microstrip ring patch antenna was designed and its performance was investigated under various types of feeding methods and dimensions. The patch dimensions and dielectric base thickness were kept constant. The simulations were performed by using Ansys HFSS programme. In simulations, FR-4 and Rogers RT-5880 dielectric base materials were preferred. The bandwidth of the antennas changes between 260 to 1160 MHz and the gain of the antennas are between 4.6 and 9.35 dB. [ABSTRACT FROM AUTHOR]

Bacalar Lake is characterized by a high saturation of calcium, bicarbonate, sulfate and silicate in its water and these conditions harbor a microbialite community. To explore the nematode fauna, associated with microbialites, 11 sites along the lake were selected. The collected microbialites were carefully dissolved and nematodes extracted manually. Nematodes were represented by 2 classes, 10 orders, 17 families, and 22 genera. Dorylaimidae and Xyalidae were the richest in genera (3 each), while the family Selachinematidae was represented by Choanolaimus, which is first reported in epicontinental systems. Dichromadora (48), Epitobrilus (31), Dorylaimus (30), Ischiodorylaimus (24), Belondira (13), Aphanolaimus (11) and Monhystera (10) were the most abundant genera. All Nematode's freshwater feeding types were present, but deposit feeders (DF) were observed with 35%. We concluded that nematodes are an important component of the metazoan fauna in microbialites from Bacalar Lake, with a higher diversity than reported in other lakes and marine environments. Nematodes can take advantage of the micro-spaced texture of microbialites and function as bioturbators, as well as escape predation, taking advantage of available food, which is reflected in the structure of nematode feeding types. More research on the interaction of microbialites-nematodes is necessary to understand their role in this poorly known environment. [ABSTRACT FROM AUTHOR]

Summary: This study provides first insights into the moss-dwelling meio-invertebrate community inhabiting mosses collected from underwater, splash-water and adjacent terrestrial habitats along a Swedish lake. Additionally, changes in both species and functional diversity of the nematode community were followed. Total meio-invertebrate mean densities and biomass peaked at 10 644.2 ± 2391.8 individuals (g dry weight (DW) moss)−1 and 14 199.3 ± 5037.3 μ g DW (g DW moss)−1 underwater, 1 m away from the shoreline, where the community was strongly dominated by rotifers, followed by nematodes. Total invertebrate biomass in terrestrial mosses was much lower, indicative of a significantly higher carrying capacity of moss patches in aquatic environments, which provide a high level of resource turnover as well as a buffer against desiccation and extreme temperature fluctuations. We found a total of 74 nematode species and maximum diversity was attained 1 m away from the shoreline and at the splash-water zone. The underwater mosses at the shoreline thus housed the most diverse and abundant assemblages of meio-invertebrates, suggesting they may play an important ecological role at the land-water interface. Evidenced by the multiple shifts in dominance, our study clearly showed that feeding types differed between habitats. The taxonomic and functional segregation of the nematode community along the ecotone further indicated that the composition of nematode species assemblages has the potential to mirror the ecological changes of the study site, even at small scales. [ABSTRACT FROM AUTHOR]

Summary: This study investigated the abundance, biomass, species richness, species distribution and feeding types of free-living nematodes in Lake Constance, a deep, oligotrophic lake in Germany. Three water depth zones, the sublittoral (13-30 m water depth), profundal (31-99 m) and deep profundal (100-250 m), were distinguished and 16 sites from each water depth zone were sampled. A high nematode species richness was determined at all three zones, with 129 species in the sublittoral, 113 in the profundal and 92 in the deep profundal. In total, 171 nematode species were identified in this study. The dominant species (relative abundance > 5%) in all water depths were Ethmolaimus pratensis , Eumonhystera filiformis , E. longicaudatula , E. vulgaris and E. andrassyi , Hofmaenneria brachystoma , Ironus tenuicaudatus , Monhystera paludicola / stagnalis , Prismatolaimus intermedius and Tobrilus gracilis. High mean densities of 507-730 indiv. 10 cm−2 were found at each water depth, with a mean overall density of 627 indiv. 10 cm−2. The high abundance resulted in a high mean biomass (1.19 mg wet weight 10 cm−2; range 0.92-1.37 mg wet weight 10 cm−2) for nematodes in Lake Constance. Deposit feeders were the dominant feeding type at all water depth zones (51.7%), followed by epistrate feeders (17.6%), chewers-omnivores (15.9%) and chewers-predators (11.0%). Suction feeders accounted for <4% in the lake as a whole. The structure of the nematode communities in the three zones correlated with sediment texture (water content, clay content), as well as total sulphur and nutrient-related parameters (ATP, bacteria, algae, C:N ratio). [ABSTRACT FROM AUTHOR]

Summary: The nematode communities of four different micro-habitats in an unpolluted first-order stream were investigated over a 13-month period in a study of the sediment and the biofilms on dead wood, macrophytes and leaf litter. Nematode abundances, biomass and secondary production were analysed, together with the species composition, proportion of feeding types and diversity of the nematode communities of the micro-habitats. Differences between the investigated micro-habitats in terms of seasonal variations, species composition, proportion of feeding types and diversity were expected. The annual mean values of nematode abundance, biomass and secondary production differed significantly between the micro-habitats. Abundances were highest on dead wood, whereas biomass and secondary production were highest in sediment. In the sediment and on leaf litter, nematode abundance and biomass showed pronounced seasonal patterns. The largest contribution to the total secondary production of the stream was from sediment nematodes. In total, 108 nematode species were detected in the micro-habitats during the 13-month study. Comparisons between them revealed differences in nematode species composition. The annual mean species number was significantly higher in sediment and on leaf litter than on dead wood and macrophytes, whereas the annual mean Shannon-Wiener index was significantly higher in sediment than at all other micro-habitats. All micro-habitats in the studied stream, as well as the stream as a whole, were dominated by nematode species belonging to the deposit feeders. Our study clearly showed that the composition of nematode communities from different micro-habitats within a single stream reach can differ markedly. [ABSTRACT FROM AUTHOR]

Abstract Wadden Sea macrozoobenthos has access to food sources of different quality. In addition to microphytobenthos (MPB) and macroalgae (e.g. Fucus vesiculosus Linnaeus, 1753), the invasive C 4 grass Spartina anglica C.E. Hubbard has become an abundant primary producer in the Wadden Sea. To elucidate the role of different primary producers for the nutrition of typical Wadden Sea consumers, we conducted a mesocosm experiment with four food treatments (S. anglica , F. vesiculosus , MPB and all three resources together) under a simulated tidal cycle. We used consumers of different feeding types—the omnivorous polychaete Hediste diversicolor (O.F. Müller, 1776), the interface-feeding bivalve Limecola balthica (Linnaeus, 1758) and the surface deposit-feeding snail Peringia ulvae (Pennant, 1777)—and analyzed their biomass, δ13C and δ15N stable isotope values and fatty acid (FA) profiles. After 4 weeks, the biomass of H. diversicolor increased in treatments that contained F. vesiculosus , but decreased in the treatment with MPB. δ13C values of H. diversicolor reflected those of the food sources provided and FA profiles varied strongly between the treatments, indicating feeding on copepods and bacteria as well as macrophytes. The biomass of P. ulvae significantly increased in treatments with S. anglica and all three resources. However, δ13C values of P. ulvae differed significantly between the treatments and were unrelated to the food sources except for MPB. FA profiles confirmed the assimilation of MPB in this species. δ13C values and FA composition of L. balthica were similar in each of the treatments and did not resemble the resources provided. Instead, the high proportion of respective marker FAs indicated feeding on plankton. δ15N values of the consumer species declined significantly in the order H. diversicolor > L. balthica > P. ulvae in each of the treatments. These results indicate different strategies in food source use of the three consumer species with the performance of the generalist feeders H. diversicolor and P. ulvae exceeding that of the selective feeder L. balthica. Highlights • Mesocosm experiment reveals diverse strategies in food use of Wadden Sea macrofauna. • Differential response of macrofauna to expanding salt marshes with invasive plants. • Lower competitiveness of L. balthica compared to H. diversicolor and P. ulvae. • Selective feeding of L. balthica on plankton as potential ecological niche. [ABSTRACT FROM AUTHOR]

The mouflon’s traditional classification as a grazer has recently been questioned, therefore new insight into the species’ feeding and digestion is needed. The presence and share of different ciliate genera in the rumen may contribute to an understanding of a species’ feeding physiology, therefore we analysed the composition of mouflon rumen ciliates and correlated their density with the percentage of different food types eaten by the animals. We found that the dominant ciliates were Entodinium spp., with a small proportion of Anoplodinium denticulatum, Eudiplodinium maggii, Epidinium ecaudatum caudatum and Dasytricha ruminantium . The main food types taken by the animals were deciduous tree leaves, grass and bramble. The density of ciliates from the Entodinium genus rose with an increase in deciduous leaves in the diet and fell with an increase of graminoids in the diet. The density of ciliates from the Anoplodinium and Eudiplodinium sub-genera increased with a rise in tree shoots and was reduced with a rise of deciduous leaves in the diet. These results confirm that the protozoal fauna vary with current food composition in intermediate feeders. [ABSTRACT FROM AUTHOR]

The pattern of changes in the macrobenthic community was studied along the south-east coast of India from the estuary to continental slope. A transect perpendicular to the coast was selected for sampling in estuary, inshore region, continental shelf and continental slope. Sampling was done in 16 stations in the depth range of 1.7–1000 m. The community structure was characterized in terms of species composition, abundance, diversity and feeding type. Four taxa were encountered in the study area comprising 181 species of polychaetes, 65 species of molluscs, 47 species of crustaceans and six species of ‘others’ (four echinoderms and two cnidarians). Polychaetes were found to be dominant at all the depths constituting 53.89% of the total abundance and 60.54% of the total number of species. Number of species and Shannon diversity of macrobenthos increased from estuary to shelf region and then decreased. The abundance was found to be maximum in the estuary and minimum in the slope. Carnivorous species were found to be dominant in the estuarine and inshore regions and surface deposit feeders in the shelf and slope regions. Dissolved oxygen decreased gradually from 30 m depth and beyond 150 m the decrease was pronounced due to the presence of the oxygen minimum zone. The distance based linear model (DISTLM) showed the environmental variables to explain about 76.45% of the total variability in macrofaunal distribution. Among the various environmental parameters, total organic carbon, depth and salinity explained more variability than others. Gradual change in community structure was quite evident with increase in depth. [ABSTRACT FROM PUBLISHER]

The annual bloom of the green macroalgal Ulva prolifera from May through July since 2008 and another of giant jellyfish Nemopilema nomurai from June through September have been frequent events in the Yellow Sea. However, the patterns of benthic ciliate communities during and after the blooms are still not known. In combination with analyses of benthic environmental factors, we investigated the distribution and community composition of benthic ciliates in the Yellow Sea in July and November 2011. In July, ciliates had high standing crops and diversity in the northern Yellow Sea, and in the inshore area off the southern Shandong Peninsula, where large numbers of green macroalgae accumulated. In November, the abundance, biomass and diversity of ciliates were high in the sea areas off the Shandong Peninsula and Changjiang estuary, where a large quantity of jellyfish occurred in August. Neither the abundance nor the biomass had significant difference between seasons, or between different compartments of the Yellow Sea. The species number, and both Margalef and Shannon-Wiener indices of ciliates were all significantly higher in November than in July. In both seasons, prostomateans and karyorelicteans consistently constituted the first and second most important ciliate groups in biomass; and carnivorous ciliates constituted the primary feeding type in terms of biomass as well as species richness, followed by bacterivores, algivores and omnivores. Compared with that in June 2007 when no macroalgae occurred, the percentage of small-sized bacterivores (e.g. Metacystis spp., Euplotes spp. and scuticociliates) increased in July 2011. The proportion of carnivorous ciliates increased in November, and this increased dominance of carnivorous ciliates may be a response to the increase in predominance of heterotrophic nanoflagellates, which might in turn be ascribed to an effect of green macroalgal and giant jellyfish blooms in the Yellow Sea. [ABSTRACT FROM AUTHOR]

We monitored for 1 year the sediment nematofauna of two headwater streams located near water resurgence from typical helocrene springs. Nematode community composition, benthic organic matter (BOM) and chlorophyll a (BChl a) were assessed in two sediment layers (0-5 and 5-10 cm depth), providing insights into nematode vertical distribution. Globally, the density, diversity and functional richness of nematodes were lower in the upper sediments, although important amounts of BChl a were available there. The assemblages differed markedly between springs, with only 41 shared species from a total of 120 species, suggesting stochastic horizontal distribution even at small geographical scales (<5 km). Bacterial-feeding nematodes dominated in the upper sediments, whereas omnivorous, fungal- and plant-feeding nematodes thrived in the deeper sediments. Reproduction by the dominant algal-feeding species, Prodesmodora arctica, was detected in August. The substantial presence of juveniles throughout the year highlighted the importance of parthenogenetic reproduction. [ABSTRACT FROM AUTHOR]

To understand how the herbivore community on beech canopies varies between two different latitudes, we assessed leaf traits and herbivory by three major feeding types (chewing, mining, and galling) at different positions in the canopy using a scaffolding system along a 1,400-km latitudinal gradient between Kuromatsunai (north) and Shiiba (south) in Japan. The chemical and morphological traits of the canopy foliage differed significantly between latitudes and between canopy parts. The leaf mass per area (LMA), leaf nitrogen, and carbon/nitrogen (CN) ratio were higher at south latitude than at north latitude. The upper canopy had a greater LMA, leaf nitrogen, and CN ratio than the lower canopy at both latitudes. On the other hand, herbivory by the three major feeding types differed significantly between latitudes and between canopy parts. The miner and galler densities were higher at south latitude than at north latitude, while the chewing herbivory was lower, showing different latitudinal patterns among feeding types. Among these feeding types, only chewing herbivory was higher in the lower canopy than in the upper canopy at both latitudes. The stepwise regression models showed that LMA and CN ratio explained spatial variation in chewing herbivory. Our study demonstrates that the latitudinal and spatial variations in leaf traits can play an important role in determining the latitudinal and spatial variations in the herbivore community on beech canopies via different responses of each feeding type. [ABSTRACT FROM AUTHOR]

Abstract: To improve the knowledge of nematode communities in the Liaohe estuary, the spatiotemporal variations of free-living nematode communities (density, diversity and trophic structure) in the protected zone (PZ) and the development zone (DZ) were seasonally studied. Soil nematode communities were analysed at the depths of 0–10 and 10–20 cm. The results showed that bacterial feeder nematodes were the most abundant trophic groups in both depths and at both sites. Nematode abundance and plant-parasitic nematodes maturity index/maturity index in the DZ were higher than that in the PZ (p < 0.05); trophic diversity, Shannon index, fungivore/bacterivore ratio and Wasilewska index in the PZ were higher than those in the DZ (p < 0.05). No significant differences were found in nematode indices between soil layers. Structural equation modelling (SEM) revealed that season, plant biomass and soil properties explained 78% of the variation in soil nematode, and plant biomass controlled nematodes indirectly through affecting soil properties. In general, anthropogenic activities could affect nematode communities, but the degree of influence varied with seasonal change. [Copyright &y& Elsevier]

We explored changes in trophic structure and species composition of freshwater nematodes in response to nutrient enrichment in microcosms for 16 mo. Succession of functional groups differed significantly among the 5 nutrient treatments, which ranged from oligotrophic to polytrophic conditions, in the 2nd half of the experiment. Differences among nutrient levels were most important for representatives of lower trophic levels, such as bacterial and algal feeders, whereas suction feeders and predators remained relatively unaffected. In contrast to our expectations, density and biomass of bacterial and algal feeders increased in the nutrient-poor treatments because of the presence of a high fraction of edible unicellular green algae and diatoms, whereas large standing stocks of inedible macrophytes developed in the highly nutrient-enriched treatments. Nematode assemblages in microcosms with intermediate or high nutrient levels were characterized by a large proportion of omnivores and predators, respectively, because of relatively low total densities. Our results also suggest a gradual change in species composition along the nutrient gradient because the degree of pairwise assemblage dissimilarity increased with corresponding differences in nutrient enrichment. Our study highlights the potential of bottom-up forces in shaping freshwater nematode assemblages and provides further evidence of pelagic-meiobenthic coupling. [ABSTRACT FROM AUTHOR]

Bacteria, protozoa and nematodes interact closely in soil ecosystems. Protozoa and nematodes eat bacteria (and occasionally each other), while bacteria defend themselves using chemical substances, resistant cell walls, irregular shapes and motility. Protozoa and nematodes are very different types of organisms, and hence apply very different feeding mechanisms; thus many protozoa can pick and choose individual bacterial cells, whereas nematodes ingest bacterial patches more uncritically. Protozoa and nematodes are both aquatic organisms whose activity depends on available soil water, but differences in size, motility, resting stages and reproductive strategies mean that the soil physico-chemical environment infl uences the activity of protozoa and nematodes differently. For example, the relative importance of protozoa compared to nematodes may shift towards protozoa in very clay-rich soils. The interactions between the three organism groups have major ecological consequences such as modifi cation of the bacterial communities and increased nitrogen mineralisation, both of which affect plant growth. Increased nitrogen mineralisation will usually be benefi cial for plant growth, whereas the grazing-induced changes in the bacterial communities can be both benefi cial and detrimental to plants. Selective protozoan grazing can favour plant inhibiting bacteria. This may be a problem in clay rich soils where protozoa have better life conditions than nematodes. [ABSTRACT FROM AUTHOR]

Lotic epilithic biofilms are submitted to seasonal disturbances (e.g. flood events, self-detachment), which influence the biomass, diversity and viability of their algal and bacterial communities. The objective of this study is to examine whether (1) biofilm-dwelling nematodes respond to such seasonal changes in terms of diversity and community structure, (2) nematode species and feeding-types distribution respond to the varied trophic situations within the biofilm, since variations in biofilm microalgal composition may represent a variation in available food. The biofilm-dwelling nematode community was monitored in a temperate river over an 18 month period with a high sampling frequency. These data were linked to environmental abiotic and biofilm biotic factors. Nematode density was positively correlated to biofilm and microalgal biomass, but was dampened by floods. A clear seasonal pattern of the community was detected (summer shift), so that two nematode groups stand out: (1) the epistrate-feeders Chromadorina bioculata (Schultze in Carus, 1857) and Chromadorina viridis (Linstow, 1876) were primarily related to diatom availability, and dominated the nematode assemblage most of the time, (2) seven species from various feeding types (deposit-feeders, suction-feeders and chewers) grew mainly under summer conditions concomitantly to a change of biofilm trophic status and microalgal composition. Overall, the results suggested that, in addition to abiotic disturbances, the availability of potential preys in the biofilm might represent an important driver of nematode community patterns. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine whether littoral nematode community patterns are shaped by lake trophic state. It was hypothesized that trophic level is associated negatively with the proportion of omnivores and positively with the percentages of bacterial feeders, but not at all with the diversity, abundance, and biomass of freshwater nematodes. Sediment samples were taken at littoral sites of eight southern Swedish lakes of different trophy in spring and autumn 2007. Trophic level was found to strongly influence species richness, as oligotrophic and mesotrophic lakes supported the greatest species numbers, whereas nematode abundance, biomass, and Shannon index were unaffected. Furthermore, our results indicated effects on the nematode community's trophic structure, with a larger proportion of predatory nematodes in oligotrophic and mesotrophic lakes but no differences in the other feeding types (bacteria, algae and suction feeders, omnivorous species). Multivariate analysis indicated a shift in species compositions along the threshold from mesotrophic to eutrophic conditions, with the presence of Tobrilus gracilis, Monhystera paludicola, Brevitobrilus stefanskii, and Ethmolaimus pratensis related to the latter. Nematode communities in oligotrophic and mesotrophic lakes were characterized by a similar species composition, with pronounced occurrences of Eumonhystera longicaudatula, Semitobrilus cf. pellucidus, Prodesmodora circulata, and Rhabdolaimus terrestris. Overall, the results suggested that lake trophic state is a major factor structuring littoral nematode communities, although intra-lake variations might be of importance as well. [ABSTRACT FROM AUTHOR]

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Summary: The study was part of a long-term CO2 enrichment field experiment (FACE: free air CO2 enrichment), using isotopically labelled CO2, at the Federal Research Institute for Rural Areas, Forestry and Fisheries (vTI) in Braunschweig (Germany). Impacts of elevated atmospheric CO2 concentration (550ppm) on nematode abundance, feeding type composition and the stable C-isotopic signatures (δ13C) of feeding types were analysed in an arable soil of a luvisol soil type and a loamy sand texture under cultivation of sugar beet and winter wheat. Two different crop growth stages were considered. The total nematode abundance was significantly higher under winter wheat compared to sugar beet cultivation and tended to increase under CO2-enriched conditions. The feeding type composition of nematodes significantly differed between crops and their growth stages. CO2 enrichment increased the relative abundance of fungivorous nematodes under winter wheat, and the relative abundance of bacterivores under sugar beet cultivation. Accordingly, under FACE conditions, the nematode channel ratio (NCR) indicated a shift towards a more fungal-based food chain under winter wheat, but towards a more bacterial-based energy pathway under sugar beet cultivation. The stable C-isotopic signatures of nematodes confirmed the ingestion of labelled C used for atmospheric CO2 enrichment. The δ13C values indicated significant FACE effects on all nematode feeding types. CO2 impacts depended on either crop type or crop growth stage, or on the combination of both. According to their food specificity, nematode feeding types were specifically affected by atmospheric CO2 enrichment due to different food qualities and quantities in the rhizosphere. The present results indicate that fungivores benefit from CO2 enrichment in arable soils under winter wheat, and bacterivores under sugar beet cultivation. Due to these changes, the soil C-cycle and decomposition processes might change as well. Generally, FACE effects differed strongly between crops and their growth stages, revealing the need to introduce more than one plant type and sampling date when CO2 enrichment effects on soil faunal communities are studied. [Copyright &y& Elsevier]

Abstract: This study investigated the spatial distribution of subtidal nematode communities along the salinity gradients of two Portuguese estuaries exposed to different degrees of anthropogenic stress: the Mira and the Mondego. The nematode communities were mainly composed of Sabatieria, Metachromadora, Daptonema, Anoplostoma, Sphaerolaimus and Terschellingia species, closely resembling the communities of Northern European estuaries. In both estuaries, nematode density and community composition followed the salinity gradient, naturally establishing three distinct estuarine sections: (i) freshwater and oligohaline – characterised by the presence of freshwater nematodes, low nematode density and diversity; (ii) mesohaline – dominated by Terschellingia, Sabatieria and Daptonema, with low total density and diversity; and (iii) polyhaline and euhaline – where nematodes reached the highest density and diversity, and Paracomesoma, Synonchiella, and Odontophora were dominant. Despite the similarities in community composition and total nematode density, the proportion of different nematode feeding types were remarkably different in the two estuaries. In Mira, selective deposit feeders were dominant in the oligohaline section, while non-selective deposit feeders were dominant in the other sections. On the contrary, in the Mondego estuary, epigrowth-feeders and omnivores/predators were dominant in the freshwater sections and in the euhaline sector of the southern arm. Differences observed along each estuarine gradient were much stronger than overall differences between the two estuaries. In the Mondego estuary, the influence of anthropogenic stressors seemed not to be relevant in determining the nematodes'' spatial distribution patterns, therefore suggesting that mesoscale variability responded essentially to natural stressors, characteristic of estuarine gradients. Nevertheless, the proportion of the different feeding types was different between the two estuaries, indicating that the response of nematode feeding guilds is able to reflect anthropogenic-induced stress and can be useful in assessing biological quality in transitional waters ecosystems. [Copyright &y& Elsevier]

Abstract: The spatial variations of meiofauna population density and the assemblage of free-living marine nematodes in areas with Avicennia marina and Rhizophora apiculata cover of Pichavaram and Parangipettai (southeast coast of India) are described. Seven meiofauna taxa were recorded, with maximum density of meiofauna (890ind.10cm−2) being recorded in an area with A. marina cover. Nematodes accounted for up to 93.1% of the total densities; other common taxa were foraminifera and polychaeta. A total of 44 species of nematodes belonging to 36 genera and 20 families were recorded. Of these, 37 species belonging to 30 genera and 17 families were recorded from Pichavaram mangrove and 14 species belonging to 10 families from a nearby artificial mangrove environment. While 16 species were common to both A. marina and R. apiculata cover, 15 species were restricted to areas with A. marina cover and 13 to areas with R. apiculata cover. Dorylaimopsis sp. was the abundant genera in areas with A. marina cover and Daptonema sp. in areas with R. apiculata cover. Only three species were common in all the five stations. Epistrate-feeders were the most abundant nematodes in areas with A. marina cover and deposit-feeders/ciliate feeders in areas with R. apiculata cover. [Copyright &y& Elsevier]

Copyright of Senckenbergiana Maritima is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Six sites within the littoral habitat of Lake Constance in Germany were studied from February 1999 to January 2000 in order to determine the influence of the inflowing River Schussen on local nematode assemblages. The sites were selected to represent a gradient of river influence within the broader river mouth area. The area as a whole was found to be rich in nematode diversity, with 106 nematode species identified. The nematode communities recorded ranged in density from 121 to 165 individuals/10 cm2 and in biomass from 108 to 503 μg wet weight/10 cm2. They were also shown to vary in terms of feeding ecology, with significant differences in the proportions of feeding types occurring among site. Deposit feeders were most abundant, followed by chewers, although the latter dominated in terms of biomass. Epistrate feeders were less common and suction feeders rare. The occurrence of epistrate feeders was linked to the concentration of algal pigment, whereas records of deposit feeders and chewers correlated with bacterial density and organic carbon content. The characters of the different nematode communities in the vicinity of the river mouth were found to reflect the transitional nature of the study area. [ABSTRACT FROM AUTHOR]

The development of an epilithic nematode community and the mode of colonisation was monitored over a 57-day period during spring in a field experiment in the littoral zone of a large oligotrophic lake. Two types of experimental units were used: one type prohibited direct colonisation via active crawling by elevating substrates into the water column and the second type had substrates placed on the lake bottom. Data from the two types of units and from nearby natural hard substrates were compared. The nematodes quickly colonised on the introduced substrates and reached maximum densities of 123 individuals per 10 cm2 after 57 days. Nematode densities on elevated and non-elevated substrates did not differ significantly. The nematode abundance and community structure showed a large initial variation, but became more stable over time and resembled the natural community structure at the end of the experiment. The maximum number of nematode species was reached after 2 weeks of colonisation, with a maximum species number on days 12 and 14 in the experimental units and on day 19 on the surrounding natural hard substrates. The five numerically dominant species, Eumonhystera vulgaris, Chromadorina bioculata, Eumonhystera filiformis, Chromadorina viridis and Daptonema dubium, accounted for most of the variation between the different communities. The results indicate that water-column transport was the main colonisation pathway of epilithic nematodes. The distribution of nematode species points to potential morphological adaptations of some species for persistence on hard substrates. [ABSTRACT FROM AUTHOR]

The Taro and Ticino rivers were sampled (maximum 15 cm depth) for nematodes during 1 year at three sites for each river and some ecological parameters were measured. The yearly mean abundance of nematodes in the river Taro was 23 individuals/10 cm2 and in the river Ticino 79 individuals/10 cm2. In the two rivers five to 15 and three to ten species, respectively, were found. The highest station (Taro 1) of the river Taro was significantly different from all the other Taro and Ticino stations both for number and species composition: bacterial feeders were the dominant group in Taro 1 (mean Maturity Index (MI) was 2.25), whereas unicellular eukaryote feeders dominated the other Taro and Ticino sites (mean MI of 2.85). Chromadorina bioculata was the most common species in both rivers, except at Taro 1, where Eumonhystera dispar dominated. Significant correlations were found between conductivity and unicellular eukaryote feeders and bacterial feeders. For the first time the Distinctness Index δ+ is used for freshwater nematodes. Comparing our communities with other Italian rivers (data taken from the literature), we detected significant differences between polluted and not polluted habitats. [ABSTRACT FROM AUTHOR]

Recent studies on meiofaunal and nematode communities have focused on soft sediments in streams, lakes and marine environments. Despite a large number of studies dealing with periphyton, meiofaunal and nematode communities, on littoral hard substrates in lakes have not yet been investigated in detail. Therefore, epilithic communities with particular emphasis on nematode species composition, were analysed in 17 Swedish lakes differing greatly in size, depth, trophic status and epilithic biomass. Nematode abundance ranged from 2.3 to 161.5 cm-2, and the abundance of nematodes relative to total meiofauna ranged from 20 to 77% (mean 53%). Fifty-eight nematode species were identified; species numbers varied from eight to 34 species per lake. The dominant species were Rhabdolaimus aquaticus, Punctodora ratzeburgensis, Eumonhystera dispar and Crocodorylaimus flavomaculatus. Deposit feeders dominated (71% of total fauna), followed by suction feeders (14%), epistrate feeders (12%) and chewers (3%). Of 3624 nematodes examined, 54% were juveniles, 35% females, 6% males and 5% gravid females. Multivariate analysis of the nematode species composition revealed significant differences in the community structures among lakes. This is the first study to show that meiofauna is a numerically abundant group within littoral periphyton communities in lakes, with nematodes representing the dominant group. [ABSTRACT FROM AUTHOR]

Abstract: Tannin-binding salivary proteins (TBSP) are considered to be counter-defences acquired in the course of evolution by animals whose natural forage contains such tannins. As tannins mostly occur in browse material but not in grasses, it is assumed that grazers do not have a need for TBSP. Whereas it has been shown in several non-ungulate species that TBSP can be induced by dietary tannins, their presence or absence in ungulates has, so far, been shown to be a species-specific characteristic independent of dietary manipulations. We investigated saliva from three rhinoceros species from zoological gardens fed comparable, conventional zoo diets. As expected, saliva from white rhinoceroses (Ceratotherum simum, grazer) had lower tannin-binding capacities than that from black rhinoceroses (Diceros bicornis, browser). Surprisingly, however, Indian rhinoceroses (Rhinoceros unicornis), commonly regarded as grazers as well, displayed the highest tannin-binding capacities of the three species investigated. It is speculated that this discrepancy might be a result of an evolutionarily recent switch to a grass-dominated diet in Indian rhinoceroses, and that the black rhinoceros, which is closer related to the white rhinoceros than the Indian species, has evolved an inducible mechanism of TBSP production. In separate trials during which the tannin content of the diets of black rhinoceroses was increased by the addition of either tannic acid or quebracho, the tannin-binding capacity of black rhinoceros saliva was increased to levels within the same range as that of Indian rhinoceroses on the conventional diets. While induction trials in white and Indian rhinoceroses remain to be performed for a full understanding of salivary anti-tannin defence in rhinoceroses, these results are the first report of an induced salivary response to increased dietary tannin levels in an ungulate species. [Copyright &y& Elsevier]

Macrobenthic zonation on sandy beaches has been studied widely, whereas meiobenthic/nematofaunal species richness and zonation patterns have received little attention. We investigated community structure, intertidal zonation of nematode species and feeding structure across a macrotidal, ultra-dissipative, sandy beach (De Panne, Belgium). A total of 88 free-living marine nematode species were recorded along transects. Average nematode densities increased from the upper beach (320±45 ind/10 cm2) towards the low-tidal level (2784±6 ind/10 cm2), which corresponds well to the better-known macrobenthic patterns on sandy beaches. While macrobenthic species richness usually increases towards the low-tidal level, nematode species richness reached highest values around the mid-tidal level (34±3 sp.). This can be explained by an optimal balance between time of submergence, oxygen supply and sediment stability. Multivariate analyses indicated four different nematode assemblages that reflect the tidal zonation patterns: the upper beach, the driftline, the middle beach association and the lower beach association. The assemblages were significantly different from each other although similarities tended to increase down the beach, indicating a more gradual transition between the mid-tidal and low-tidal assemblages. Non-selective deposit feeders dominated all zones except in the driftline, where epistratum feeders were dominant. Percentage of very fine sand and percentage of shell fragments provided the best granulometric variables in determining these assemblages. [Copyright &y& Elsevier]

We investigated the effect of 4-nonylphenol (NP) on nematode communities in the sediment of freshwater microcosms. Seven treatments were dosed with various concentrations of NP over a period of six weeks by using a controlled-release method (NP1-NP7; maximum sediment concentrations: 0.29-3.37 mg/kg dry wt). Four microcosms were not exposed to NP and served as controls. Nematode communities were analyzed over a period of 15 weeks, including sampling dates before, within, and after the NP application. Communities were characterized in terms of total nematode abundance and species diversity (Shannon index and evenness), as well as composition of species, feeding types, and different life-history strategists (maturity index [MI]). Species composition was analyzed by using a multivariate method (principal response curves). Total nematode abundance and species diversity were not affected in any of the NP-treated microcosms. However, in the highest dosed treatment, NP-induced changes in the nematode communities occurred. Species and feeding types composition, as well as the MI, were affected in the postapplication period, with species composition being altered most clearly. In the highest dosed treatment, deposit-feeding species, classified as colonizers (Eumonhystera), increased in dominance, whereas epistrate feeders and chewers (Prodesmodora and Tobrilus) decreased in relative abundance compared to the control. [ABSTRACT FROM AUTHOR]