Abundance Values Research Articles

Predation Risk, Foraging and Reproduction of an Insectivore Fish Species Associated with Two Estuarine Habitats

Pneumatophore fringes and mudflats are extremely valuable habitats and provide structures on which many fish species benefit in terms of food and reduced predation risk. We analyzed the spatiotemporal patterns in feeding habits, reproductive aspects and effects of predatory fish presence to assess the ecological drivers of the common halfbeak, Hyporhamphus unifasciatus, in a Brazilian estuary. Sampling was conducted during the rainy and dry periods. In summary, the results demonstrated that the number of predatory fishes was a strong predictor of population abundance and biomass, followed by pneumatophore complexity. The abundance and biomass values tended to increase with increasing habitat structural complexity towards the upper estuary. There was evidence that fish exhibited movement during the rainy season related to spawning events and subsequent juvenile recruitment in this area. Hymnoptera was the item most frequently ingested and made the greatest contributions to the volume of diet in habitat types throughout the year. There was an increase in the condition factor in the rainy season, which was associated with energy reserves, reproduction and growth (fitness). We concluded that predation is an important ecological process that operates at local spatial scales and that, together with the density of pneumatophores, it could affect the abundance of common halfbeak populations associated with estuarine habitats.

Sigmoid Eruption Associated with the X9.3 Flare from AR 12673 Drives the Gradual Solar Energetic Particle Event on 2017 September 6

Large gradual solar energetic particle (SEP) events can pose a radiation risk to crewed spaceflight and a significant threat to near-Earth satellites; however, the origin of the SEP seed particle population, and how these particles are released, accelerated and transported into the heliosphere are not well understood. We analyze NOAA active region (AR) 12673, which was the source responsible for multiple large gradual SEP events during 2017 September, and found that almost immediately after each significant eruptive event associated with SEPs an enhanced Si/S abundance ratio was measured by Wind, consistent with the previous work by Brooks et al. The EUV Imaging Spectrometer (EIS) onboard Hinode took data roughly 8 hr before the second SEP event on 2017 September 6, which allowed the regions of enhanced Si/S abundance ratio in the AR to be determined. We have shown that the AR contains plasma with elemental abundance values detected in situ by Wind. In particular, the plasma originates from the core of the AR, similar to Brooks et al., but in the moss (footpoints) associated with hot sigmoidal AR loops. The sigmoid, which contains highly fractionated plasma, erupts and propagates toward an Earth-connected magnetic null point, providing a direct channel for the highly fractionated plasma to escape and be detected in the near-Earth environment.

The recreational value of birding and crane abundance

Abstract We estimate the economic value of birding, which is an important ecosystem service produced by bird populations in recreation areas. Our research identifies the link between values and species richness as well as the abundance of the sandhill crane (Grus canadensis), which migrates each year through our study area. Sandhill crane stopovers at state and federal wildlife areas can attract many birders. We estimate this nonmarket value using the zonal travel cost method and data from the eBird project on wildlife areas in Indiana. We compare crane counts based on eBird with those from the Indiana Department of Natural Resources (DNR). We find important differences depending on whether we use eBird or DNR counts. On average, birders are willing to pay $28 per trip to sites in the study area and less than $1 per trip to see an additional species, while the value of 1000 more cranes is either about $1 or $10 per trip depending on how abundance is measured.

The Influence of Waters of Lake Baikal on the Spatiotemporal Dynamics of Phytoplankton in the Irkutsk Reservoir

On a model natural object, the Lake Baikal–Angara River–Irkutsk Reservoir (IR), we studied changes in the qualitative and quantitative characteristics of phytoplankton communities over three seasons in 2023 depending on seasonal changes in habitat parameters. Of the 151 identified taxa, Chrysophyta (57), Chlorophyta (41) and Bacillariophyta (24) predominated in diversity. Over the entire observation period, the highest values of total biomass and total abundance were detected in the IR in June (hydrological spring) at a water temperature of 10.0–12.7 °C, and the lowest in August, despite the fact that the water warmed up to 20 °C. No mass blooms of Cyanobacteria were observed. Statistical analysis of species abundance profiles revealed that phytoplankton community structure varied across time and space. The direct effect of cold lake waters on the structure of phytoplankton in the reservoir was observed only in early June. In summer and autumn, the structures of phytoplankton in the lake and in the reservoir differed, even at the same water temperature. Low concentrations of phosphates and nitrates, high species diversity, the presence of cold-water species and species with a wide range of temperature preferences formed a dynamic spatiotemporal structure of IR phytoplankton, distinct from other temperate reservoirs, including Lake Baikal. The results obtained are important for understanding the mechanisms of formation of the flora of artificial reservoirs of temperate latitudes and for their monitoring, taking into account seasonal dynamics and the context of global climate warming.

Epiplastic Algal Communities on Different Types of Polymers in Freshwater Bodies: A Short-Term Experiment in Karst Lakes

The increasing amount of plastic debris in water ecosystems provides a new substrate (epiplastic microhabitats) for aquatic organisms. The majority of research about epiplastic communities has focused on seawater environments, while research is still quite limited and scattered concerning freshwater systems. In this study, we analyze the first stages of colonization on different types of plastic by a periphytic algae community (its composition and dominant species complex) in freshwater bodies located in a nature reserve (within the Middle Volga Basin). A four-week-long incubation experiment on common plastic polymers (PET, LDPE, PP, and PS), both floating and dipped (~1 m), was conducted in two hydrologically connected karst water bodies in July 2023. The composition of periphytic algae was more diverse (due to the presence of planktonic, benthic, and periphytic species) than the phytoplankton composition found in the water column, being weakly similar to it (less than 30%). Significant taxonomic diversity and the dominant role of periphytic algae were noted for diatoms (up to 60% of the total composition), cyanobacteria (up to 35%), and green (including Charophyta) algae (up to 25%). The composition and structure of periphytic algae communities were distinct between habitats (biotope specificity) but not between the types of plastic, determined primarily by a local combination of factors. Statistically significant higher values of abundance and biomass were demonstrated for some species, particularly for Oedogonium on PP and Nitzschia on LDPE (p-value ≤ 0.05). As colonization progressed, the number of species, abundance, and dominance of individual taxa increased. In hydrologically connected habitats, different starts of colonization are possible, as well as different types of primary succession (initiated by potentially toxic planktonic cyanobacteria or benthic cyanobacteria and mobile raphid diatoms). Within the transparency zone, colonization was more active on the surface (for example, in relation to green algae on PP (p-value ≤ 0.05)). These results indicate a tendency for microalgae communities to colonize actively submerged plastic materials in freshwater, and they may be useful in assessing the ecological status of these aquatic ecosystems.

Pregnancy during COVID 19 pandemic associated with differential gut microbiome composition as compared to pre-pandemic.

The first two years of the COVID-19 pandemic and subsequent health mandates resulted in significant disruptions to daily life, creating a period of heightened psychosocial stress in myriad aspects. Understanding the impact of this period on pregnant individuals' bacteriomes is crucial as pregnancy is a period of heightened vulnerability to stress and its sequelae, anxiety and mood disorders, which have been demonstrated to alter gut microbiome composition. In a prospective cohort study (N = 12-26) conducted from February 2019 to August 2021, we examined psychometric responses and rectal microbiome swabs from pregnant individuals. Full-length 16S rRNA sequencing followed by calculation of diversity metrics and relative abundance values were used to interrogate fecal microbiome community composition across pandemic groups. Distinct shifts in bacterial diversity and composition were observed during early to late pregnancy in the pandemic group, including lower relative abundance of pathogenic and lesser-known taxa. However, distribution of stress and depressive symptoms did not significantly differ from the pre-pandemic period while the correlation between stress and depressive symptoms dissipated during the pandemic. Our findings suggest that living through the COVID-19 pandemic altered the gut microbiome of pregnant individuals, independent of perceived stress.

Seed and foliar application of nano-selenium improves sesame triacylglycerols and oil yield via photosynthetic pigment and enzymatic and chemical antioxidant enhancement revealed by spectrophotometric, UHPLC-analysis and chemometric modeling.

The current study aimed to investigate the effects of plant-mediated selenium nanoparticles (SeNPs) on plant growth, photosynthetic pigments, antioxidant activity, and the triacylglycerol profile of sesame (Sesamum indicum L.). The green synthesis of SeNPs was achieved using garlic extract, resulting in spherical nanoparticles with an average size range of 70-75 nm. Three SeNP treatments (T3, 30 ppm; T4, 40 ppm; and T5, 50 ppm) were applied through seed and foliar spray on six sesame varieties (V1, TS-5; V2, TH-6; V3, Til-18; V4, Niab Millennium; V5, Niab Pearl; and V6, NS-16). All enzymatic antioxidant parameters showed an increase in the treated groups, such as SOD (74.4% in V1 at T4), POD (43% in V5 at T5), APX (62% in V1 at T3), and GPX (31.56% in V3 at T4). CAT showed the highest percentage improvement in T5 for V1, V2, V4, and V5, while V3 and V4 exhibited the highest values at T4. Likewise, seed antioxidant parameters also showed increase in antioxidant activity, highest total phenolic content (6.06 mg GAE/g) was found at T5 treatment with percent increase of 27.41%, but the highest percent increase was found to be at T4 treatments in V1 with increase of 46.83%. Percent oil yield was also noted to be higher as highest percent (60%) oil yield was obtained at T4 treatment in V3. Ultra High Performance Mass-Spectrometry (UHPLC-MS) analysis and chemometric modeling suggested a total of 10 triacylglycerol (TG) biomarkers separating untreated groups, with higher relative abundance values at T4 and T5 treatments compared to control. PCA and correlation analysis showed clustering of untreated groups from T4 and T5, which suggests that these two treatments result in higher accumulation of oil. A generalized linear model with ANOVA showed a highly significant impact of treatments on all the growth and oil parameters, with significance involvement of varieties. The interaction between variety and treatment showed no significant effect on the growth and oil biomarkers of sesame. However, it can be concluded that the T4 and T5 treatments (40 ppm and 50 ppm) of SeNPs, applied through seed and foliar methods, have a strong influence on the overall growth and oil yield of sesame. This warrants further transcriptomic and molecular analysis to gain deeper insight into the mechanisms of action of SeNPs.

Assessing methods for telluric removal on atmospheric retrievals of high-resolution optical exoplanetary transmission spectra

Recent advancements in ultra-stable ground-based high-resolution spectrographs have propelled ground-based astronomy to the forefront of exoplanet detection and characterisation. However, the resultant transmission and emission spectra of exoplanetary atmospheres are inevitably contaminated by telluric absorption and emission lines due to the light's transmission through the Earth's atmosphere above the observatory. Retrieving accurate atmospheric parameters depends on accurate modelling and removal of this telluric contamination while preserving the faint underlying exoplanet signal. There exist many methods to model telluric contamination, whether directly modelling the Earth's transmission spectrum via radiative transfer modelling, or using a principal component analysis (PCA)-like reconstruction to fit the time-invariant features of a spectrum, and removing these models from the observations. We aimed to assess the efficacy of these various telluric removal methods in preserving the underlying exoplanetary spectra. We compared two of the most common telluric modelling and removal methods molecfit and the PCA-like algorithm SysRem using planetary transmission spectra injected into three high-resolution optical observations taken with ESPRESSO. These planetary signals were injected at orbital periods of P = 2 days and P = 12 days, resulting in differing changes in radial velocity during transit. We then retrieved various injected atmospheric model parameters in order to determine the efficacy of the telluric removal methods, as well as their effect on the transmission spectra of exoplanets with varying orbital architectures. For the close-in, high velocity injected signal, we found that SysRem performed better for species that are also present in the Earth's atmosphere--with accurate and precise retrieval of atmospheric abundances and $T$-$P$ profiles, across each of the datasets. As we moved to slower moving signals at larger orbital separations, for one of the three datasets SysRem dampened the planetary H$_2$O signal, leaving the retrieved abundance value unconstrained. In contrast, the H$_2$O signal was preserved for the telluric modelling method molecfit . However, this behaviour was not ubiquitous across all three of the injected datasets, with another dataset showing a more precise H$_2$O/Fe ratio when preprocessed with SysRem . These conflicts highlight the importance of testing individual high-resolution dataset reduction routines independently to ensure real exoplanetary signals are preserved.

Spatial ratios of native and alien species of vascular plants in forests in the southwest of Kyiv and the adjacent areas

Using the case of isolated oak-hornbeam forests in the green zone of the Kyiv Urban Area, spatial ratios of native and alien species of vascular plants were determined. The sampling method used by Whittaker (1980) made it possible to discover the following: the abundance of 134 species per 60 m2 in 12 localities varied from 880 to 1 individual/m2 with an average of 106.5 individuals/m2. The total species abundance of alien species ranged from 423 to 1 individual/m2. The highest total abundance values were observed in Adoxa moschatelliana – 880, Impatiens parviflora – 423, Galium odoratum – 371, Rabelera holostea – 367, and Prunus avium – 254 individuals/m2. At five spatial levels in 12 localities, 230 species from 142 genera and 58 families of vascular plants were found, including 48 alien species from 38 genera and 23 families. High species occurrence along with aboriginal forest species (Adoxa moschatelliana in 12 localities, Acer platanoides, Carpinus betulus, Galium odoratum, Prunus avium, Tilia cordata, Viola odorata in 10 localities) is characteristic only of Impatiens parviflora – 12 localities and Acer negundo – 10 localities. In general, the spatial ratios of native and alien species confirm the trends of recreational digression of hornbeam-oak forests in the green zone of the Kyiv Urban Area.

Macrophyte Diversity and Ecosystem Services in Wetlands of Eastern Ranchi: A Multi-site Analysis of Abundance, Frequency, and Importance Value Index Patterns

Macrophytes, visible aquatic and semi-aquatic plants, are integral components of wetland ecosystems, playing crucial roles in maintaining biodiversity, providing ecosystem services, and ensuring ecological stability. This research examines the distribution, abundance, frequency, diversity, and ecosystem services of macrophytes in several wetlands (W1-W7) located in the eastern part of Ranchi district, Jharkhand, India. The study sites include Bundu Lake, Hindalco Pond, Choga Bada Talab, Raja Bandh, Kita Uparbandh, Tamar Bada Talab, and Rukka Dam. A quantitative assessment using quadrat sampling and phytosociological methods was conducted from September 2022 to March 2023 to ensure accurate data collection and analysis. The study documented 78 macrophyte species belonging to 33 families and 58 genera. Emergent macrophytes were found to be the dominant life form, constituting 69% of the recorded species. Several species demonstrated high frequency and abundance across multiple study sites, including Pontederia crassipes Mart., Alternanthera philoxeroides (Mart) Griseb., Hydrilla verticillata (L.f.) Royle, Ipomoea aquaticaForssk., and Nymphoides hydrophyllum (Lour.) kuntze. To assess the diversity and ecological characteristics of the macrophyte communities, various diversity indices were calculated. These included the Shannon-Wiener index, Simpson's index, Margalef index, and Pielou's Evenness index. The results of these analyses revealed high levels of macrophyte diversity and evenness within the studied wetlands. Twenty-one macrophytes were identified as key species and nine species as rare species based on their IVI (Importance Value Index) scores. The key species were found to provide essential ecosystem services, including erosion control, water quality improvement, nutrient cycling, carbon sequestration, and habitat provision for other organisms. This research contributes significantly to our understanding of macrophyte diversity patterns and traits-based ecosystem services in wetland ecosystems. The findings of this study have important implications for the development and implementation of effective conservation strategies for these vital wetland ecosystems in the eastern Ranchi (W1- W7).

Assessing the diversity and species composition in macroinvertebrate assemblages thriving in shallow water macroalgal habitats: Structural complexity is not always better

The assemblages of motile and sessile macroinvertebrates [mainly arthropods (peracarids), mollusks and annelids] were studied in three shallow macroalgal habitats from the NW Mediterranean Sea. Habitats were respectively dominated by three macroalgae: Ericaria mediterranea, a canopy-forming fucoid with repeatedly ramified cylindrical branches and spine-like projections; Cystoseira compressa, a canopy-forming fucoid with occasionally ramified compressed branches; and Ellisolandia elongata, a turf-forming, repeatedly branched, geniculate calcified alga. A total of 175,800 macroinvertebrate specimens, belonging to 228 taxa were collected. Macroinvertebrate assemblages in E. mediterranea habitat showed the highest abundances and number of taxa (104,412 specimens and 184 taxa), followed by those from C. compressa (49,128 specimens and 157 taxa) and E. elongata habitats (22,260 specimens and 144 taxa). Annelids were the most diverse group (43% of taxa) and amphipods the most abundant (78% of individuals). Macroinvertebrate abundances, alpha-diversity and species composition significantly differed among habitats and/or sites, while the number of taxa did not show significant differences neither among sites nor among habitats. Despite the simpler morphology of E. elongata respect to fucoid species, E. elongata habitat registered the lowest macrofauna abundance values but the highest alpha-diversity. Amphipods were the most abundant group in fucoid algae habitats (82–85%), while bivalves dominated in E. elongata one. Annelid polychaetes were the third more abundant group. Macroinvertebrate assemblages thriving in E. elongata habitat were always different to those found in fucoid algae habitats. Amphipods Protohyale schmidtii, Jassa herdmani, Jassa morinoi and Stenothoe gallensis were the most abundant species in fucoid algae habitats, while several species of Mytilidae, together with Caprella liparotensis, S. gallensis and nematodes dominated in E. elongata turfs. Differences observed are explained according to differences in algal morphological complexity and natural variability.

Assessment of Lepidopteran Pest Dynamics in Maize: Dominance of Spodoptera frugiperda and Implications for Targeted Management in Himachal Pradesh, India

Maize (Zea mays L.) plays a crucial role in the agricultural economy of India, particularly in Himachal Pradesh, where it serves as a vital crop for food, feed, and fodder. This study assessed the distribution, and relative abundance of lepidopteran pests infesting maize during the kharif, 2022-23 across two agro-climatic zones of Himachal Pradesh. Surveys identified five key lepidopteran pests: Spodoptera frugiperda, Chilo partellus, Mythimna separata, Agrotis ipsilon, and Euproctis spp. Among all, S. frugiperda is the only pest occurring among the major three crop stages of maize. The findings revealed that S. frugiperda was the most dominant pest, with relative abundance values of 19.57 per cent in Zone I and 18.94 per cent in Zone II during the seedling stage, increasing to 30.87 per cent and 30.40 per cent during the vegetative stage, respectively. In contrast, other pests like C. partellus, M. separata, A. ipsilon, and Euproctis spp. exhibited variable distribution patterns, with some showing limited occurrence. In conclusion, this study underscores the necessity for targeted pest management strategies to address dominant and subdominant lepidopteran pests in maize cultivation in Himachal Pradesh. The results offer valuable insights that can inform focused pest control efforts, with the potential to significantly enhance sustainable maize production, crop resilience and overall productivity in the region.

Metagenomic analysis of deep-sea bacterial communities in the Makassar and Lombok Straits

The extreme conditions of the deep-sea environment, including limited light, low oxygen levels, high pressure, and nutrient scarcity, create a natural habitat for deep-sea bacteria. These remarkable microorganisms have developed unique strategies to survive and adapt to their surroundings. However, research on the diversity of deep-sea bacteria, both culture-dependent and culture-independent, in Indonesian waters remains insufficient. This study focused on exploring the biodiversity of deep-sea bacteria, specifically in the Makassar and Lombok Strait, the main Indonesian throughflow pathway characterized by relatively fertile water, which serves as an important deep-sea region. High-throughput DNA sequencing of full-length 16S rRNA was employed to construct a genomic database. The results of the bioinformatic analysis revealed that two stations, 48 and 50 (Makassar Strait), exhibited a more similar community structure of deep-sea bacteria than did station 33 (Lombok Strait). Among the predominant phyla found at a depth of 1000 m, the top ten were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Planctomycetes, Acidobacteria, Nitrospinae, Verrucomicrobia, Candidatus Melainabacteria, and Cyanobacteria. Furthermore, the genera Colwellia, Moritella, Candidatus Pelagibacter, Alteromonas, and Psychrobacter consistently appeared at all three stations, albeit with varying relative abundance values. These bacterial genera share common characteristics, such as psychrophilic, halophilic, and piezophilic tendencies, and are commonly found in deep-sea ecosystem. The environmental conditions at a depth of 1000 m were relatively stable, with an average pressure 10 MPa, temperature 4.68 °C, salinity 34.58 PSU, pH 8.06, chlorophyll-a 0.29 µg/L, nitrate 3.19 µmol/L, phosphate 6.32 µmol/L and dissolved oxygen (DO) 2.90 mg/L. The bacterial community structures at the three sampling stations located at the same depth (1000 m) exhibited similarities, as indicated by the closely aligned similarity index values.

Differences in gut microbiota and metabolites between wrestlers with varying precompetition weight control effect.

This study intended to analyze the effects of body weight control by the diet, training adaptation, and gut microbiota metabolites of wrestlers in the week leading up to competition. According to the weight difference of wrestlers from the target weight 1 wk before the competition, those whose weight control effectiveness is less than 2 kg were classified as the CW group, whereas more than 2 kg were classified as the CnW group. The body weight, body composition, and diet of wrestlers were recorded; urine samples were taken for standard urine testing, and stool samples were collected for the analysis of gut microbiota and metabolites. The data showed that the relative values of carbohydrate and fat energy in the CnW group were significantly higher than those of the CW group, but the relative values of protein energy were significantly lower. The white blood cells, occult blood, and protein appeared in urine in the CnW group. The microbiota with higher abundance values in the CnW group were positively correlated with the relative value of carbohydrate energy, while the abundance value of Streptococcus was negatively correlated, and the functional prediction of differential bacteria was related to riboflavin and selencompound metabolism. The differential metabolites of CW/CnW group were functionally enriched in the processes of lipid and amino acid metabolism. Overall, the extent of weight control in wrestlers was correlated with sensible dietary patterns, adaptability to training load, and distinct gut microbiota and metabolites.NEW & NOTEWORTHY The purpose of this study is to observe the differences in precompetition diet structure, adaptability to training, gut microbiota, and metabolites of wrestlers with different weight control effects and analyze the correlation between them, aiming to provide scientific guidance and advice on weight control for wrestlers.

Estimation of bacterio‐, picophyto‐ and nanophytoplankton abundance in the Middle Caspian Sea by flow cytometry

Aim. For the first time, flow cytometry has been used to study the structure and functional characteristics of bacterio‐, pico‐ and nano‐ phytoplankton in the Middle Caspian during the bloom period in early September 2022.Water samples were taken at different horizons (from the surface to the bottom layer) at a series of stations along the western coast of the Caspian Sea on the border between its northern and central parts to quantitatively assess heterotrophic bacterioplankton, picophyto‐ and nanophy‐ toplankton. Sampling was undertaken in early September 2022 under summer hydrological conditions with water surface temperatures ranging from 24.7°C to 26.7°C. Sample analysis was performed using flow cytometry.Extremely high concentrations of picophytoplankton (up to 1.8×105 cells/mL), probably of Synechococcus picocyanobacteria, were detected off the northwestern coast of the Middle Caspian. Very high values of nanophytoplankton abundance (up to 1.6×105 cells/mL), dominated by small flagellates, were also found. A clear spatial uncoupling of pico‐ and nanophytoplankton was revealed. Maximum levels of nanophytoplankton were confined to the area of intensive phytoplankton blooming with high concentrations of chlorophyll a, while picophytoplankton reached peak abundance further south, outside this area. The influence of the thermocline on the vertical structure of microbial communities was detected. The concentrations of picophytoplankton and the proportion of physiologically active HNA‐bacteria decreased sharply under the thermocline.The results obtained indicate the leading role of the smallest phototrophs in the Caspian pelagial and emphasise the need for further comprehensive studies of Caspian microbial communities using modern methods.

Structure of Zooplanktocenoses of Water Bodies of Zoogenic Origin of Different Types in a Specially Protected Natural Territory

The features of the structure of zooplankton in beaver ponds and the course of successions in zooplanktocenoses have been studied in the territory of State Natural Reserve “Kologrivsky Les” named after M.G. Sinitsyn. Ponds are divided into groups according to the nature of the watercourse on which they are formed, the height of the floodplain, and the duration of existence. The seasonal succession of zooplankton for all types of ponds begins with the predominance of juvenile stages of Copepoda. In the summer, in newly formed ponds and ponds on rivers with high floodplains, a typical zoogenic transformation of communities is observed occurs with the development of large Cladocera. In long-term ponds on streams and rivers with low floodplains, the dominance of Rotifera and small Cladocera, characteristic of anthropogenic eutrophication, and the highest average values of abundance and biomass, indices of species diversity and evenness were noted.

Comparison of distinct gut bacterial communities in different stage of prediapause and nondiapause larvae in Loxostege sticticalis.

Symbiotic microorganisms in insects regulate multiple physiological functions, widely participating in nutrient metabolism, immune regulation, and crucial regulatory roles in development. However, little is known about how microbial factors might respond to the preparation of insect diapause. The gut bacterial communities of Loxostege sticticalis larvae induced at different photoperiod of long (LD16:8, nondiapause) and short (LD12:12, prediapause) daylength were compared, by 16S rRNA Illumina MiSeq. A total number of 42 phylum, 78 classes, 191 orders, 286 families, 495 genera, and 424 species were identified in the intestinal bacterial community of L. sticticalis larvae. Alpha diversity and beta diversity analyses revealed significant differences between nondiapause and prediapause larvae. In non-diapause larvae, the dominant intestinal bacteria were Firmicutes and Proteobacteria. In specific, in 3rd and 4th instar larvae, the main intestinal bacteria were Staphylococcus, while in 5th instar, it was JC017. For the prediapause larvae, the dominant phylum in 3rd instar larvae was Firmicutes, with the dominant genus of Staphylococcus, while in 4th and 5th instar larvae was Bacteroidota, with the dominant genus 4th instar was Staphylococcus, and in 5th instar was JC017. KEGG functional prediction analysis revealed that functional bacterial groups involved in metabolism had the highest abundance values. Specifically, the amino acid metabolism of metabolism-related functional genes in the 3rd instar prediapause larvae was significantly lower than that in the 4th and 5th instar prediapause larvae and the non-diapause treatment. However, the carbohydrate metabolism in 3rd instar prediapause larvae was significantly higher than that in 4th and 5th instar prediapause larvae and non-diapause treatments. The dominant bacterial phylum in the prediapause larvae at different stages of L. sticticalis was varied, and there were significant differences in community diversity and richness. These results suggest a complex interaction between the hosts' physiological state and its gut microbiota, indicating that bacterial communities may assist insects in adapting to diapause preparation by regulating their metabolic levels. This study lays the foundation for further understanding the physiological mechanisms by which intestinal microorganisms regulate overwintering dormancy in the L. sticticalis.

Study on Phosphorus Variability Characteristics and Response Mechanism of Microbial Community during Sediment Resuspension Process

Submerged plants and related disturbances can affect both the phosphorus (P) release and the microbial communities in sediments. In this study, a sediment resuspension system was constructed, and P variability characteristics influenced by Vallisneria natans (V. natans) and the response mechanism of the microbial community were studied. The results indicated that the total phosphorus (TP) content increased from 678.875 to 1019.133 mg/kg and from 1126.017 to 1280.679 mg/kg in sediments and suspended solids (SSs) during the sediment resuspension process, respectively. Organic P (OP) increased by 127.344 mg/kg and 302.448 mg/kg in sediments and SSs after the disturbance, respectively. The microbial communities in the sediments and the leaves of V. natans had higher Chao values after the disturbance, while Shannon values decreased after the disturbance compared to the control in SSs. Proteobacteria had the highest abundance with the value of 51.1% after the disturbance in the sediments and SSs, and the abundance values of Proteobacteria in rhizomes and leaves of V. natans could reach 73.2% on average. Chloroflexi, Acidobacteria, and Firmicutes were also the main phyla in the sediment resuspension system. Sodium hydroxide extractable P (NaOH-P) in sediments could reduce the bioavailability of this P fraction under disturbance conditions. The decrease in the abundance of Bacteroidetes and Nitrospirae indicated that they were more sensitive to the disturbance, and the rotational speed changed the survival conditions for the Bacteroidetes and Nitrospirae. The response mechanism of microbial community during the sediment resuspension process could reflect the influence of the microbial community on the changing characteristics of P and could provide a theoretical foundation for P control at the micro level.

Regulation Effect of Toxocara canis and Anthelmintics on Intestinal Microbiota Diversity and Composition in Dog

Toxocara canis is an intestinal roundworm that can cause serious zoonotic parasitic diseases. Drontal Plus® Tasty (Dog) is a kind of commercial drug used to treat T. canis infection. Febantel, Praziquantel, and Pyrantel pamoate (PP) are its main component. However, there are few studies investigating the impact of Drontal Plus® Tasty (Dog) and its primary ingredients on the intestinal microbiota of dogs. In this study, we first collected the intestinal content samples of the dogs which administrated with anthelmintics or saline by sterile catheters, then used 16S rRNA high-throughput sequencing technology combined with a variety of bioinformatic analysis methods to analyze the effect of anthelmintics on intestinal microbiota. First, the results of the α and β diversity analysis showed that the abundance and diversity of intestinal microbiota decreased with T. canis infection, and increased after anthelmintic treatment. Then, we found the dominant species (the value of relative abundance > 0.05) was both 28 on phylum and genus levels, besides the most dominant species was Bacillota on phylum level and Segatella and Clostridium_sensu_stricto were most dominant on genus level. Futher analyzing the differences in microbiotal composition on phylum level, we found that Drontal Plus® Tasty treatment could significantly increase the proportion of Bacillota, while Febantel, Praziquantel, or PP could induce the significantly changes of Bacillota and Bacteroidota. In addition, by analyzing the differences in microbiotal composition on genus level, we found that anthelmintic could significantly decreased the relative abundance of Clostridium_sensu_stricto and significantly increased the abundance of Segatella. However, Drontal Plus® Tasty had no regulatory effect on the abundance of Segatella. In short, these finding showed that various anthelmintics all have significant effects for changing the abundance and diversity of host intestinal microbiota.

Распределение рыб семейства Cottidae в юго-восточной части Баренцева моря (к западу от о. Долгий)

The distribution of Cottidae species in the southwestern part of the Barents Sea (Pechora Sea) based on materials from ichthyological surveys carried out in the summer of 2010–2023 is shown. Cottidae species were maximum 1.7 % of the total catch. A total of 7 species have been noted. The most abundant Cottidae species in Pechora Sea is arctic staghorn sculpin G. tricuspis (85 % frequency of occurrence), shorthorn sculpin M. scorpius (62 %) and ribbed sculpin T. pingelii (46 %). Values of the total abundance of the Cottidae was diverse: 1.2 to 757.6 ind/km2 and 0.002 to 21.906 kg/km2.