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This study offers a comprehensive analysis of grasshopper diversity and distribution across different sites of Matiari district, Sindh, Pakistan during 2021-22 by using advanced statistical and ecological methodologies. This research documented ten grasshopper species, revealing significant spatial and temporal patterns. Acrotylus humertianus and Aiolopus thalassinus were widely distributed, with Acrotylus humertianus showing peak abundance in Mooro Lakho, while Oedaleus rosesense demonstrated the highest overall density, reaching up to 20 individuals per site. Notably, species richness peaked at ten species in Hala during April 2022, indicating substantial temporal variability. Principal Component Analysis (PCA) highlighted distinct ecological niches, with Acrotylus humertianus scoring highly on PC1, suggesting it thrives under specific conditions. The Shannon-Wiener Index revealed Bhit Shah and Mooro Lakho as the most diverse sites, while Simpson's Diversity Index indicated lower diversity in Saedabad. The correlation analysis showed a moderate positive relationship between temperature and grasshopper density (r = 0.452), while humidity and soil type had minimal effects. Generalized Linear Model (GLM) analysis identified Locusta migratoria as the most effective model, with the lowest Deviance, AIC, and BIC values, reflecting its optimal fit. The study emphasizes the complex interplay between environmental factors and grasshopper populations, providing crucial insights for biodiversity conservation and ecological research. These results highlight the dynamic nature of grasshopper ecology and underscore the need for targeted conservation strategies based on environmental and temporal variations. [ABSTRACT FROM AUTHOR]

Poyang Lake wetland plays an important ecological service function. Frequent drought events have caused significant changes in the distribution pattern of wetland plants. This study analyzed the changes in the distribution elevation of wetland plants in Poyang Lake from 2000 to 2020, including the optimal elevation, and upper and lower limit elevations, and revealed the impacts of drought on the ecological niches of typical wetland plants. The results showed that the wetland plants were distributed in a regular strip pattern according to the elevation gradient. The Polygonum hydropiper-Phalaris arundinacea (PP), Carex cinerascens (Cc), Phragmites australis-Triarrhena lutarioriparia (PT), and Artemisia selengensis (As) communities were mainly distributed at elevations of 8.70-13.62 m, 10.35-14.99 m, 12.00-16.28 m, and 11.82-18.46 m, with optimal elevations of 11.16, 12.67, 14.14, and 15.14 m, respectively. Although the optimal elevations and upper limit elevations of four typical wetland plants exhibited different changing trends, their lower limit elevations showed the significant downward trends, especially for Cc and PP communities. Moreover, drought caused a varying degree of decrease (0.16-0.34 m) in the optimal elevations of four typical wetland plants, the upper and lower limit elevations of most wetland plants had also decreased in dry years. [ABSTRACT FROM AUTHOR]

Estimates of global fungal diversity have varied widely, suggesting a range from fewer than one million to over 10 million species, with each of the estimates drawing data from various criteria. In 2022, Fungal Diversity published a special issue on fungal numbers. It had been hoped that the editorial would provide a more accurate account of the numbers of fungi. Instead, it was concluded that this was not possible based on present evidence and, some of the data necessary for accurate assessments was put forward, and the present paper expands on this short article. The review first looks at estimates of fungal numbers and what these estimates are based on. It then presents future research needs that will help us to gain a more accurate estimate of fungal numbers. This includes work that needs to be done in tropical rainforests, where the greatest diversity is expected, where whole rainforests, canopy diversity, and palm fungi are addressed. Case studies for lichens and associated fungi, soil and litter fungi, evidence from particle filtration, freshwater fungi, marine fungi, mushrooms, and yeasts will also be given. Once we have such information, we can obtain a more accurate estimate of fungal numbers. [ABSTRACT FROM AUTHOR]

The Pseudomonas aeruginosa genome can change to adapt to different ecological niches. We compared four genomes from a Mexican hospital and 59 genomes from GenBank from different niches, such as urine, sputum, and environmental. The ST analysis showed that high-risk STs (ST235, ST773, and ST27) were present in the genomes of the three niches from GenBank, and the STs of Mexican genomes (ST167, ST2731, and ST549) differed from the GenBank genomes. Phylogenetic analysis showed that the genomes were clustering according to their ST and not their niche. When analyzing the genomic content, we observed that environmental genomes had genes involved in adapting to the environment not found in the clinics and that their mechanisms of resistance were mutations in antibiotic resistance-related genes. In contrast, clinical genomes from GenBank had resistance genes, in mobile/mobilizable genetic elements in the chromosome, except for the Mexican genomes that carried them mostly in plasmids. This was related to the presence of CRISPR-Cas and anti-CRISPR; however, Mexican strains only had plasmids and CRISPR-Cas. blaOXA-488 (a variant of blaOXA50) with higher activity against carbapenems was more prevalent in sputum genomes. The virulome analysis showed that exoS was most prevalent in the genomes of urinary samples and exoU and pldA in sputum samples. This study provides evidence regarding the genetic variability among P. aeruginosa isolated from different niches.

Diversification at the plot level, through the use of intercropping (mixtures of crops), is an alternative to the conventional system of intensive agriculture, based on monospecific, usually single-variety canopies. Intercropping has been shown to provide benefits in terms of disease control. However, competition phenomena and the heterogeneity of the associated crops raise new ecological questions, particularly with regard to the dynamics and evolution of parasite populations. No study has assessed the potential impact of these associations on the dynamics of pathogenic species complexes. Changes in the nutritional status of plants and therefore in their physiological susceptibility to infection within intercropping systems could contribute to an increased diversity of ecological niches and thus affect the composition of the parasitic complex and its spatiotemporal dynamics. In this review, focusing on foliar diseases of fungal origin, and after outlining some elements of the biology and epidemiology of these fungal diseases, we will (i) describe the mechanisms that contribute to the composition of disease clusters and that drive interactions, but we will also review the strategies that these foliar diseases have adopted to deal with these co-infections; (ii) define how intercropping can lead to changes in epidemic dynamics, in particular by presenting the mechanisms that have a direct and indirect effect on disease evolution; and (iii) present the approach that should be adopted to properly study intercropping correctly in a multi-infection situation. [ABSTRACT FROM AUTHOR]

Loharghat Forest Range, within the Indo-Burma biodiversity hotspot, features diverse habitats like wetlands, scrublands, grasslands, tropical and deciduous forests. Chandubi, a vital tectonic wetland in the landscape, is designated as Important Bird Area (2003) and Key Biodiversity Area (2005) but remains largely unexplored. This study aims to establish a baseline database of avifaunal assemblages from the Loharghat Forest Range in Kamrup District, Assam, which includes the Mayang Reserved Forest and Barduar Reserved Forest. The forest is protected and managed by the local community. The surveys were conducted between August 2021 to June 2023. The study revealed the occurrence of a total of 224 avian species belonging to 20 orders and 58 families. The birds are further categorised on the basis of their seasonal movements, diets, and rarity in the region. Our findings indicate that the community-managed forests have a rich and diverse avifauna. [ABSTRACT FROM AUTHOR]

Ecological niches and beta diversity are fundamental concepts providing insight into the structure and functioning of marine ecosystems. Both concepts help in understanding how communities are distributed in different habitats and how marine ecosystems respond to environmental change. Here, the study brings a functional approach to the relationship between phytoplankton ecological niches and beta diversity. Phytoplankton community (from pico- to microphytoplankton) was addressed during a spring bloom of Phaeocystis globosa and diatoms, from the eastern English Channel (EEC) toward the southern North Sea (SNS) in 8 distinct water bodies, from late-April 2017 to mid-May 2017. An automated flow cytometer was used to discriminate phytoplankton by their optical properties at the single-cell level from continuous subsurface pumping marine waters, allowing the characterization of 11 phytoplankton functional groups (PFGs) from pico- to microphytoplankton. The spatial segregation of PFGs was performed from total abundance and Local Contribution to Beta Diversity (LCBD) calculations, from the most abundant to the marginal PFGs, through niche's overlap. Nanoeukaryotes (RedNano) associated with Phaeocystis globosa and picophytoplankton associated with Synechococcus spp. (OraPicoProk) were the less marginal PFGs. However, the low niche overlap between these groups revealed they have contrasting habitat affinity. While nanoeukaryotes prefer estuarine habitats or at the vicinity of an estuary, Synechococcus spp. was more likely along the coasts without freshwater influence. Picoeukaryotes with high chlorophyll-a content (RedPico III), coccolithophores (HsNano), and Pseudo-nitzschia-like (RedMicro I) were highly marginal revealing a patchy distribution. Finally, the beta regression predicted changes in community composition (i.e., LCBD values) influenced positively by temperature and the distance to the coast and negatively by salinity. The overall contribution of the PFGs to these changes (i.e., Species Contribution to Beta Diversity) was positively linked to their niche position and negatively related to their environmental tolerance. [ABSTRACT FROM AUTHOR]

It is generally believed that mycorrhiza is a microecosystem composed of mycorrhizal fungi, host plants and other microscopic organisms. The mycorrhiza of Rhododendron dauricum is more complex and the diverse morphology of our investigated results displays both typical ericoid mycorrhizal characteristics and ectomycorrhizal traits. The characteristics of ectendoomycorrhiza, where mycelial invade from the outside into the root cells, have also been observed. In order to further clarify the mycorrhizal fungi members and other fungal communities of R. dauricum mycorrhiza, and explore the effects of vegetation and soil biological factors on their community structure, we selected two woodlands in the northeast of China as samples—one is a mixed forest of R. dauricum and Quercus mongolica, and the other a mixed forest of R. dauricum, Q. mongolica, and Pinus densiflor. The sampling time was during the local growing season, from June to September. High-throughput sequencing yielded a total of 3020 fungal amplicon sequence variants (ASVs), which were based on sequencing of the internal transcribed spacer ribosomal RNA (ITS rRNA) via the Illumina NovaSeq platform. In the different habitats of R. dauricum, there are differences in the diversity of fungi obtained from mycorrhizal niches, and specifically the mycorrhizal fungal community structure in the complex vegetation of mixed forests, where R. dauricum is found, exhibits greater stability, with relatively minor changes over time. Soil fungi are identified as the primary source of fungi within the mycorrhizal niche, and the abundance of mycorrhizal fungi from mycorrhizal niches in R. dauricum is significantly influenced by soil pH, organic matter, and available nitrogen. The relationship between soil fungi and mycorrhizal fungi from mycorrhizal niches is simultaneously found to be intricate, while the genus Hydnellum emerges as a central genus among mycorrhizal fungi from mycorrhizal niches. However, there is currently a substantial gap in the foundational research of this genus, including the fact that mycorrhizal fungi from mycorrhizal niches have, compared to fungi present in the soil, proven to be more sensitive to changes in soil moisture. [ABSTRACT FROM AUTHOR]

Introduction: Bacterial communities play crucial roles in the functioning and resilience of aquatic ecosystems, and their responses to water pollution may be assessed from ecological niches. However, our understanding of such response patterns and the underlying ecological mechanisms remains limited. Methods: In this study, we comprehensively investigated the effects of water pollution on the bacterial structure and assembly within different ecological niches, including water, sediment, submerged plant leaf surfaces, and leaf surfaces, using a 16S high-throughput sequencing approach. Results: Ecological niches had a greater impact on bacterial community diversity than pollution, with a distinct enrichment of unique dominant phyla in different niches. This disparity in diversity extends to the bacterial responses to water pollution, with a general reduction in α-diversity observed in the niches, excluding leaf surfaces. Additionally, the distinct changes in bacterial composition in response to pollution should be correlated with their predicted functions, given the enrichment of functions related to biogeochemical cycling in plant surface niches. Moreover, our study revealed diverse interaction patterns among bacterial communities in different niches, characterized by relatively simply associations in sediments and intricate or interconnected networks in water and plant surfaces. Furthermore, stochastic processes dominated bacterial community assembly in the water column, whereas selective screening of roots and pollution events increased the impact of deterministic processes. Discussion: Overall, our study emphasizes the importance of ecological niches in shaping bacterial responses to water pollution. These findings improve our understanding of the complicated microbial response patterns to water pollution and have ecological implications for aquatic ecosystem health. [ABSTRACT FROM AUTHOR]

Simple Summary: Here, we described and compared the morphology of the nervous system of the late larval stage of bivalve mollusks, pediveligers, using confocal microscopy. Pediveligers from four ecological groups were studied: burrowing (Callista brevisiphonata, Mactromeris polynyma), cementing (Pododesmus macrochisma, Crassostrea gigas), attaching to byssus (Kellia japonica, Crenomytilus grayanus) and mobile forms (Mizuhopecten yessoensis, Azumapecten farreri). We tried to identify possible similarities and/or differences in a number of structures of the nervous system in pediveligers of different species and correlate them with the lifestyle of a particular ecological group. We have not found a direct connection between the presence or absence of a number of peripheral neurostructures with an ecological group, but we have identified a possible evolutionary connection. A stomatogastric neuron communicating with the apical organ was found in species from the Heterodonta clade. The enteric nervous system and unrelated to the apical organ neurons present in Pectinida were also detected. Here, we describe the nervous system structures from pediveligers of eight bivalve species (Callista brevisiphonata, Mactromeris polynyma, Crenomytilus grayanus, Kellia japonica, Mizuhopecten yessoensis, and Azumapecten farreri) with different modes of life in their adult stages, corresponding to the ecological niches that they occupy (burrowing, cemented, byssally attached, and mobile forms). We have identified neuromorphological features of the central and peripheral nervous systems in larval bivalves. We show that the unpaired sensory apical organ is still present in pediveligers along with the developing paired cerebral ganglia characteristic of an adult mollusk. Pediveligers have the pleural ganglia connected to the pedal ganglia via the pedal nerve cords and to the visceral ganglia via the lateral nerve cords. We have found a number of structures of the peripheral nervous system whose presence varies between pediveligers of different species. Mactromeris, Callista, and Pododesmus have 5-HT-immunopositive stomatogastric neurons, whereas the Yesso and Farrer's scallops have an FMRFamide-immunopositive enteric nervous system. The innervation of the anterior part of the velum is connected to a system of the apical organ and cerebral ganglia, and the innervation of the posterior part is connected to the visceral ganglia. Most differences in the structure of the peripheral elements of the nervous system are species-specific and weakly depend on the ecological niche that pediveligers occupy. [ABSTRACT FROM AUTHOR]

Polysaccharides are complex carbohydrates and are abundant in the marine environment. Microbes degrade and utilize them using Carbohydrate-active enzymes (CAZymes), which mediate polysaccharides into the marine carbon cycle. With the continued supply of polysaccharides from the marine environment, tidal flats are also abundant in polysaccharides, resulting in an abundance of marine polysaccharide degrading strains. In this study, three novel strains, designated as D37T, M208T, and SA7T, were isolated from the intertidal sediment samples located in Zhoushan, Zhejiang and Huludao, Liaoning, PR China. The phylogenetic trees using the 16S rRNA gene and genome sequences showed that the three novel strains belonged to the genus Maribacter. The highest 16S rRNA gene sequence similarities between the three novel strains and other strains of the genus Maribacter were 98.7%, 99.2%, and 98.8%, respectively, while the ANI, AAI, and dDDH values between the three strains and the other strains of the genus Maribacter were 70-86%, 67-91%, and 17-30%, respectively, supporting their affiliation as novel species. Combined with other phenotypic and genotypic characterization in this study, three novel species are proposed as Maribacter polysaccharolyticus sp. nov., Maribacter huludaoensis sp. nov., and Maribacter zhoushanensis sp. nov., respectively, for the three strains. Furthermore, we compared all available genomes of Maribacter representatives and found that Maribacter strains could be divided into two groups (A and B). The two groups are different in genome size and G + C content and gene densities of CAZyme, peptidase, and sulfatase. Group A possesses more CAZymes which are related to degrading laminarin, fucoidan, mannan, xylose, and xylan. This result suggests that the two groups may have different niche adaptation strategies. Our study contributes to a better understanding of the role of marine flavobacteria in biogeochemical cycles and niche specialization.

Disgust is an adaptive system hypothesized to have evolved to reduce the risk of becoming sick. It is associated with behavioural, cognitive and physiological responses tuned to allow animals to avoid and/or get rid of parasites, pathogens and toxins.Little is known about the mechanisms and outcomes of disease avoidance in wild animals. Furthermore, given the escalation of negative human‐wildlife interactions, the translation of such knowledge into the design of evolutionarily relevant conservation and wildlife management strategies is becoming urgent.Contemporary methods in animal ecology and related fields, using direct (sensory cues) or indirect (remote sensing technologies and machine learning) means, provide a flexible toolbox for testing and applying disgust at individual and collective levels.In this review/perspective paper, we provide an empirical framework for testing the adaptive function of disgust and its associated disease avoidance behaviours across species, from the least to the most social, in different habitats. We predict various trade‐offs to be at play depending on the social system and ecology of the species.We propose five contexts in which disgust‐related avoidance behaviours could be applied, including endangered species rehabilitation, invasive species, crop‐raiding, urban pests and animal tourism.We highlight some of the perspectives and current challenges of testing disgust in the wild. In particular, we recommend future studies to consider together disease, predation and competition risks. We discuss the ethics associated with disgust experiments in the above contexts. Finally, we promote the creation of a database gathering disease avoidance evidence in animals and its applications. [ABSTRACT FROM AUTHOR]

Aim. To reveal mutual relations between species of the genus Nalassus in taxocenes and the division of ecological niches during cohabitation.Material and Methods. Observations and collection of adult beetles and food objects were carried out in 2020–2022 in Dagestan, North Ossetia, Kabardino‐Balkaria, Karachay‐Cherkessia, Krasnodar Region (Russia) and Abkhazia. The nutrition of beetles was observed directly in nature at night with headlamps, and in some cases in laboratory conditions using the test cafeteria method. The number of beetles per area was counted on 100 × 4 m transects. The number, sexual structure and diurnal activity (feeding, copulation) were observed with the pause of 15 to 25 minutes. We measured temperature (the range from −4 to +40°C) and humidity (the range from 0 to 100%) by loggers every 7 minutes.Results. New localities for seven known species of Nalassus are presented. The new species N. (Caucasonotus) ritsanus M. Nabozhenko, sp. n. is described from environs of Ritsa Lake in Abkhazia and it is compared with other Abkhazian representatives of the subgenus Caucasonotus. We revealed or added information about trophic relations for eight species of the genus; lichenophagy is typical for the majority of species; phytophagy and saprophagy were registered for Nalassus for the first time; algophagy was fixed for two species. The number, sex structure in micropopulations and ranges of air temperature and humidity during the period of imagoes activity were analyzed.Conclusion. The most important and perhaps the only strategy for reducing competition in the cohabitation of Nalassus in the Caucasus is a trophic specialization. An occupation of open landscapes by Caucasian Nalassus did not play a role in the subgeneric differentiation, but was partially accompanied by a transition from lichenophagy to phytophagy and saprophagy.

Spatial co‐occurrence patterns are determined by environmental factors, such as food availability or habitat characteristics and by biotic associations. When resources are limited, competition which implies a dominant hierarchy can shape species assemblage. Here, we study space and time co‐occurrence of steppe passerines during the breeding season in a natural steppe habitat, its modulation by environmental filtering, potential biotic interactions and random processes. We applied the joint species distribution model of hierarchical modelling of species community (HMSC) to data on species presence–absence and environmental, temporal and spatial covariates acquired from seven plots in a natural steppe in central Spain during two consecutive years. Our results reveal the patterns of bird species co‐occurrence and suggest that this assemblage might be competitively structured. The assemblage appears to be configured around one dominant species, the Eurasian skylark, which establishes principally negative associations with many of the coexistent species. Our results contribute to the understanding of how competition and dominance processes, together with ecological constraints and other biotic associations, shape bird assemblages. [ABSTRACT FROM AUTHOR]

It is generally believed that mycorrhiza is a microecosystem composed of mycorrhizal fungi, host plants and other microscopic organisms. The mycorrhiza of Rhododendron dauricum is more complex and the diverse morphology of our investigated results displays both typical ericoid mycorrhizal characteristics and ectomycorrhizal traits. The characteristics of ectendoomycorrhiza, where mycelial invade from the outside into the root cells, have also been observed. In order to further clarify the mycorrhizal fungi members and other fungal communities of R. dauricum mycorrhiza, and explore the effects of vegetation and soil biological factors on their community structure, we selected two woodlands in the northeast of China as samples—one is a mixed forest of R. dauricum and Quercus mongolica, and the other a mixed forest of R. dauricum, Q. mongolica, and Pinus densiflor. The sampling time was during the local growing season, from June to September. High-throughput sequencing yielded a total of 3020 fungal amplicon sequence variants (ASVs), which were based on sequencing of the internal transcribed spacer ribosomal RNA (ITS rRNA) via the Illumina NovaSeq platform. In the different habitats of R. dauricum, there are differences in the diversity of fungi obtained from mycorrhizal niches, and specifically the mycorrhizal fungal community structure in the complex vegetation of mixed forests, where R. dauricum is found, exhibits greater stability, with relatively minor changes over time. Soil fungi are identified as the primary source of fungi within the mycorrhizal niche, and the abundance of mycorrhizal fungi from mycorrhizal niches in R. dauricum is significantly influenced by soil pH, organic matter, and available nitrogen. The relationship between soil fungi and mycorrhizal fungi from mycorrhizal niches is simultaneously found to be intricate, while the genus Hydnellum emerges as a central genus among mycorrhizal fungi from mycorrhizal niches. However, there is currently a substantial gap in the foundational research of this genus, including the fact that mycorrhizal fungi from mycorrhizal niches have, compared to fungi present in the soil, proven to be more sensitive to changes in soil moisture.

In the 1970s, the concept of sport addiction appeared in scientific literature, warning of the addictive properties of exercise when taken to extremes. Appearing in over 6500 peer-reviewed articles in Google Scholar from 1979 to 2017, this construct is of interest to the fields of mental health and sport sociology as it provides a heuristic case to consider the conditions which allow for a category-in-the-making to gain meaning despite its absence from leading classification systems. Using Hacking's framework of ecological niches, this review of literature provides a critical examination of "sport addiction" and aims to investigate the driving forces and the means by which social actors from the scientific community negotiate the landscape and boundaries of this emerging disorder. The results highlight the prominence of psychology in the diffusion of the construct and the reticence of the medical world to legitimize it as a mental health category. [ABSTRACT FROM AUTHOR]

Purpose: Dicrocoeliosis can be an important cause of production loss in ruminants due to the cost of liver condemnation at slaughter. The aim of the present study was to determine the prevalence of Dicrocoelium infection and to predict the ecological niches and climatic variables that support dicrocoeliosis in the Himalayan ranges of Pakistan. Methods and Results: Dicrocoelium was detected in 33 of 381 liver samples and 238 of 6060 blood samples taken from sheep and goat herds in the area. The prevalence of dicrocoeliosis was higher in sheep than in goats and highest in females aged more than 3 years. An environmental risk map was created to predict active zones of transmission and showed the highest probability values in central parts of the Chitral district in the northwest of Pakistan. Climatic variables of the mean monthly diurnal temperature range (Bio2), annual precipitation (Bio12), and normalised difference vegetation index (NDVI) were found to be significantly (p < 0.05) associated with the presence of Dicrocoelium infection. Conclusion: Together, the findings of this study demonstrate the most suitable ecological niches and climatic variables influencing the risk of dicrocoeliosis in the Himalayan ranges of Pakistan. The methods and results could be used as a reference to inform the control of dicrocoeliosis in the region. [ABSTRACT FROM AUTHOR]

Urbanization not only profoundly alters landscape profiles, ecosystems and vertebrate faunal diversity but also disturbs microbial communities by increasing stochasticity, vulnerability, biotic homogenization, etc. However, because of the buffering effect of host species, microbial communities are expected to be influenced by both host species and urbanization stresses. Therefore, the impacts of urbanization on animals' microbial symbionts could be more complex and uncertain. In this study, we quantified the urbanization degree of sampling sites and surveyed the gut and skin microbes of three amphibian host species in different sites in urban parks and nearby villages of Chengdu, Southwest China. Furthermore, a co-occurrence network analysis, the phylogenetic normalized stochasticity ratio and Sloan neutral community models were applied to infer the impact of urbanization on symbiotic microbial communities. For the three host species, urbanization increased the diversity of symbiotic microbes and the number of keystone microbial taxa. However, the negative effects of such increased diversification were evident, as the community stochasticity and co-occurrence network structure vulnerability also increased, while the network structure complexity and stability were reduced. Finally, the community stochasticity had positive associations with the network vulnerability, implying that the existence of many transient symbiotic rare microbial taxa in urban parks makes the symbiotic microbial community structure more fragile. Conclusively, urbanization increased the symbiotic microbial diversity at the cost of community stability; the results provide a new perspective for better understanding the complex triangulated environment--host--microbe relationship. [ABSTRACT FROM AUTHOR]

Cytochrome P450 monooxygenases (P450s/CYPs) are ubiquitous enzymes with unique regio- and stereo-selective oxidation activities. Due to these properties, P450s play a key role in the biosynthesis of natural metabolites. Mycobacterial species are well-known producers of complex metabolites that help them survive in diverse ecological niches, including in the host. In this study, a comprehensive analysis of P450s and their role in natural metabolite synthesis in 2666 mycobacterial species was carried out. The study revealed the presence of 62,815 P450s that can be grouped into 182 P450 families and 345 subfamilies. Blooming (the presence of more than one copy of the same gene) and expansion (presence of the same gene in many species) were observed at the family and subfamily levels. CYP135 was the dominant family in mycobacterial species. The mycobacterial species have distinct P450 profiles, indicating that lifestyle impacts P450 content in their genome vis a vis P450s, playing a key role in organisms' adaptation. Analysis of the P450 profile revealed a gradual loss of P450s from non-pathogenic to pathogenic mycobacteria. Pathogenic mycobacteria have more P450s in biosynthetic gene clusters that produce natural metabolites. This indicates that P450s are recruited for the biosynthesis of unique metabolites, thus helping these pathogens survive in their niches. This study is the first to analyze P450s and their role in natural metabolite synthesis in many mycobacterial species. [ABSTRACT FROM AUTHOR]

Here, we explored how variations in the allopatric speciation scenario, specifically ecological vs. vicariant allopatry, relate to climatic niche change in sister species. We selected two sister species pairs of North American hummingbirds (Calypte anna, C. costae , Basilinna leucotis, B. xantusii) that diverged 2.5 and 3.6 million years ago, under ecological (arid climate tendency during Pliocene) and vicariant (Baja California peninsula separation) allopatric processes, respectively. We constructed the climatic niche of each species using occurrence records and estimated the distance, similarity, and unique fraction of climatic niche between sister species. Calypte species showed moderate niche divergence (Euclidean distance between centroids = 1.94, Sørensen index of similarity = 0.080, unique fraction of hypervolume in C. costae = 0.57, and C. anna = 0.95). However, contrary to expectations, Basilinna species, which diverged under a vicariant scenario, displayed clear niche divergence (Euclidean distance between centroids = 3.78, Sørensen index of similarity = 0.0001, and unique fraction of hypervolume in B. xantusii = 0.98, and B. leucotis = 0.99). We explained dissimilarity in climatic niches between Basilinna species by the ecological divergence between habitats of disjunct populations, which would have also been associated with increased aridity during the Pliocene. [Display omitted] • Type of allopatry affects the degree of niche conservatism in the speciation process. • We tested it in hummingbirds speciation under geographical and ecological allopatry. • Soft ecological allopatry in Calypte species led to expected niche divergence. • Hard geographical allopatry in Basilinna species led to unexpected niche divergence. • Environmental changes in the Pliocene and niche truncation may explain these patterns. [ABSTRACT FROM AUTHOR]

Here, we describe the nervous system structures from pediveligers of eight bivalve species (Callista brevisiphonata, Mactromeris polynyma, Crenomytilus grayanus, Kellia japonica, Mizuhopecten yessoensis, and Azumapecten farreri) with different modes of life in their adult stages, corresponding to the ecological niches that they occupy (burrowing, cemented, byssally attached, and mobile forms). We have identified neuromorphological features of the central and peripheral nervous systems in larval bivalves. We show that the unpaired sensory apical organ is still present in pediveligers along with the developing paired cerebral ganglia characteristic of an adult mollusk. Pediveligers have the pleural ganglia connected to the pedal ganglia via the pedal nerve cords and to the visceral ganglia via the lateral nerve cords. We have found a number of structures of the peripheral nervous system whose presence varies between pediveligers of different species. Mactromeris, Callista, and Pododesmus have 5-HT-immunopositive stomatogastric neurons, whereas the Yesso and Farrer’s scallops have an FMRFamide-immunopositive enteric nervous system. The innervation of the anterior part of the velum is connected to a system of the apical organ and cerebral ganglia, and the innervation of the posterior part is connected to the visceral ganglia. Most differences in the structure of the peripheral elements of the nervous system are species-specific and weakly depend on the ecological niche that pediveligers occupy.

This paper presents an approach to studying rangeland degradation by using remote sensing data, geographic information systems, and ecological niche theory. The role of environmental factors and land use in the spatial distribution of degraded rangelands in the Central Caucasus was assessed. Degradation stages were modelled in R using ENVIREM predictors, VIF test to select noncorrelated variables, ENMeval package to select the optimal model parameters, and the Maxent method to develop distribution models in the dismo package. Selected models had AUCtest, AUCtrain and CBI values close to 1, deltaAICc and AUCdiff values close to 0, and quite low AICc values. Environmental predictors of climate type (Thornthwaite aridity index and Emberger's pluviothermic quotient) were explanatory variables for least disturbed rangelands, while topography (Terrain roughness index) largely explained the distribution of most disturbed grasslands. Quantitative (Schoener's D) and graphical (Kernel density estimation, analysis of predictive maps) assessment revealed a significant overlap of 'ecological niches' and potential ranges of grasslands at different degradation stages, which indirectly supports the hypothesis of the important role of overgrazing in their degradation. Livestock management is likely to help restore disturbed mountain meadow steppes to steppe grasslands. Restoration of the arid shrub ecosystems to steppe grasslands or meadow steppes probably requires additional agricultural practices. [ABSTRACT FROM AUTHOR]

The sympatric complex of the northern Dolly Varden Salvelinus malma from the basin of Lake Azabachye is represented by four forms with a narrow long-term trophic specialization. Lake–river predators feed mainly on three-spined stickleback Gasterosteus aculeatus. Lake–river benthivorous are differentiated into two trophic groups; one of them (group G) feeds on amphipods and the other (group A) consumes mollusks (Mollusca) and caddis fly larvae (Trichoptera). Brook chars feed on amphibiotic insects (Insecta). The long-term food segregation of Dolly Varden forms is confirmed by differences in the degree of infection by parasites and in the ratios of stable isotopes, 15N/14N and 13C/12C, in the muscles. The indicator parasites are Eubothrium salvelini and Dibothriocephalus spp. for lake–river predators, Cystidicola farionis and Crepidostomum metoecus for lake–river benthivorous of group G, Diplostomum spp. for lake–river benthivorous of group A, and Salmonema ephemeridarum and Cucullanus truttae for brook chars. Predators and benthivorous of group G are characterized by high values of the 15N/14N ratio in the muscles, benthivorous of group A by high 13C/12C values, and brook chars by low values of 15N/14N and 13C/12C. Lake–river predators and benthivorous live together and are distributed throughout the lake and lake channel; brook chars inhabit tributaries. The sympatric complex of S. malma in the basin of Lake Azabachye is the second most diverse complex after the char complex in Lake Kronotskoe. [ABSTRACT FROM AUTHOR]

The differentiation by microsites of the population of dung beetles inhabiting horse droppings in the southern Sikhote-Alin, Primorsky krai, has been studied for the first time. The heterogeneity of the substrate has a significant effect on the distribution of beetles among microstations. The key factor affecting the seasonal dynamics of the species composition, abundance, and biomass of beetles in different parts of the droppings are the temperature and humidity regime. It is shown that the confinement of certain species of dung beetles to areas of horse manure can serve as a way of dividing their ecological niches and a way of avoiding competition within one functional group. [ABSTRACT FROM AUTHOR]

In recent years, Japanese quince (Chaenomeles japonica) plantations in Latvia have increased. Interest in breeding Japanese quince is also known in other European countries and Russia. The occurrence and harmfulness of fungal diseases have become increasingly significant. However, there is a lack of overall information in the literature about the diversity of fungi afflicting C. japonica. In our study, we aimed to determine the diversity of fungi associated with C. japonica in Latvia, with the possibility of identifying the fungi that are most characteristically associated with certain parts of the plant. Our research was conducted from 2017 to 2019 in eight Japanese quince plantations in Latvia. Samples of plant parts with disease symptoms were collected. Pure cultures of fungi were obtained and identified using ITS region sequencing. We determined the relative density of identified genera of fungi, which were grouped using hierarchical cluster analysis depending on the plant part from which they were found. Various disease-like symptoms were observed and described. A total of 538 isolates of fungi were obtained that belong to 36 genera and represent different ecological niches. Fusarium, Alternaria, Botrytis, and Sarocladium were the genera most frequently found during our study. The number of identified cases of fungal genera differed depending on the part of the plant from which the fungi were obtained. However, it is not possible to relate a specific genus of fungus to only one certain part of a plant. Further research is needed to clarify the pathogenicity of detected fungi and the composition of species in the detected genera of fungi. [ABSTRACT FROM AUTHOR]

Glyphosate and its metabolite aminomethylphosphonic acid (AMPA) draw great concern due to their potential threat to aquatic ecosystems. The individual and combined effects of glyphosate and AMPA on aquatic plants in different ecological niches need to be explored. This study aimed to investigate the ecotoxicity of glyphosate and AMPA on the emergent macrophyte Acorus calamus, phytoplankton Chlorella vulgaris, and submerged macrophyte Vallisneria natans after their exposure to glyphosate and AMPA alone and to their mixture. Medium and low concentrations of glyphosate (≤ 0.5 mg L−1) significantly inhibited the growth of V. natans and promoted the growth of C. vulgaris (P 0.05). AMPA (≤ 5.0 mg L−1) did not significantly influence the relative growth rate (except C. vulgaris) or malonaldehyde levels but significantly altered the expression levels of chlorophyll-related genes and superoxide dismutase [Cu-Zn] genes in the aquatic plants examined. AMPA mainly affected the oxidative phosphorylation pathway in V. natans and not those in other two plants, indicating that V. natans was more sensitive to AMPA-induced oxidative damage. Moreover, antagonistic effects on plant growth were observed when plants were exposed to low concentrations of glyphosate + AMPA (≤ 0.1 + 0.1 mg L−1). When the concentration of glyphosate + AMPA reached 0.5 + 0.5 and 5.0 + 5.0 mg L−1, the growth of the submerged macrophyte was additively or synergistically inhibited, but the growth of the emergent macrophyte and phytoplankton was antagonistically inhibited. Our results indicated that both the individual and combined effects of glyphosate and AMPA might alter the vertical structure of shallow lakes and accelerate the conversion of shallow lakes from grass-based to algal-based lakes.

Cephalopods are ancient mollusks that can be found in many different ecological niches in the ocean ranging from the intertidal zone to the deep-sea abyss. In order to adapt to a lifestyle in various habitats, cephalopods have evolved a variety of locomotory modes to accommodate their respective habitats. Most cephalopods have relatively high metabolic rates due to their less efficient swimming mode by jet propulsion. This lifestyle is characterized by a high level of energy expenditure, fueled exclusively by protein diets that are rapidly digested and may produce metabolic nitrogenous waste NH3/NH4 +accumulation and acid-base disturbances. This study observed that the NH4 +transport rate in pelagic bigfin reef squid (Sepioteuthis lessoniana) is two times faster than benthic common octopus (Octopus vulgaris). Inhibition of Na+/H+ exchangers (NHEs) showed significant disruption of NH4 + and H+ excretory processes in gills of octopus but not in squid. However, inhibition of vacuolar-type H+-ATPase (VHA) significantly disrupts NH4 + and H+ transport rates in gills of both animals. Accordingly, for NH4 + and H+ homeostasis, benthic octopus with lower aerobic respiration rates utilize both active and Na+-driven secondary transport machinery. In order to avoid NH4 + accumulated in the blood, pelagic squids with higher aerobic respiration rates prefer active NH4 + and H+ transport mechanisms that consume ATP intensively.

Pseudomonas aeruginosa, a ubiquitous opportunistic pathogen, is a leading cause of chronic infection of airways in cystic fibrosis (CF) patients. Chronic infections typically arise from colonization by environmental strains, followed by adaptation of P. aeruginosa to the conditions within the CF airway. It has been suggested that oxygen availability can be an important source of selection causing trait changes associated with the transition to chronic infection, but little data exist on the response of P. aeruginosa to varying levels of oxygen. Here, we use a diverse collection of P. aeruginosa strains recovered from both CF patients and environmental sources to evaluate the role of oxygen availability in driving adaptation to the CF lung while also accounting for phylogenetic relatedness. While we can detect a signal of phylogeny in trait responses to oxygen availability, niche of origin is a far stronger predictor. Specifically, strains isolated from the lungs of CF patients are more sensitive to external oxidative stress but more resistant to antibiotics under anoxic conditions. Additionally, many, though not all, patho-adaptive traits we assayed are insensitive to oxygen availability. Our results suggest that inferences about trait expression, especially those associated with the transition to chronic infection, depend on both the available oxygen and niche of origin of the strains being studied. [ABSTRACT FROM AUTHOR]

In this study, high-throughput sequencing technique was used to analyze the differences in bacterial structure between the stem, needle and root parts of different resistant Pinus massoniana before and after Bursaphelenchus xylophilus infestation for the first time. It was found that with the infestation of Bursaphelenchus xylophilus, the magnitude of change in bacterial structure in different ecological niches of low and high resistant P. massoniana showed that pine stem > pine needles > root system. Firstly, the overall bacterial structure was more stable in different parts of high resistant P. massoniana compared to low- resistant P. massoniana. Secondly, the species and number of bacteria in each ecological site of different resistant P. massoniana were root > pine stem > pine needles. At the same time, the number and species of bacterial flora were much more in the highly-resistant P. massoniana than in the less resistant P. massoniana. It is inferred that resistance in P. massoniana is positively correlated with bacterial species and abundance in Pinus massoniana. The study also showed that most of the bacteria in the high-resistant P. massoniana were found in the root system, with fewer species and numbers of bacteria in the needle part, while bacteria in the low-resistant P. massoniana were also found in the needle and there was a significant change in the bacterial flora of it. Changes in the abundance of Methylobacterium spp., Pseudomonas spp., Pseudomonas spp., Pseudomonas spp., Hymenobacter spp. and Pantotrichum spp. within its branches were positively correlated with the infestation of B. xylophilus. The above findings can provide data to support the discovery of new biocontrol strains. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa, a ubiquitous opportunistic pathogen, is a leading cause of chronic infection of airways in cystic fibrosis (CF) patients. Chronic infections typically arise from colonization by environmental strains, followed by adaptation of P. aeruginosa to the conditions within the CF airway. It has been suggested that oxygen availability can be an important source of selection causing trait changes associated with the transition to chronic infection, but little data exist on the response of P. aeruginosa to varying levels of oxygen. Here, we use a diverse collection of P. aeruginosa strains recovered from both CF patients and environmental sources to evaluate the role of oxygen availability in driving adaptation to the CF lung while also accounting for phylogenetic relatedness. While we can detect a signal of phylogeny in trait responses to oxygen availability, niche of origin is a far stronger predictor. Specifically, strains isolated from the lungs of CF patients are more sensitive to external oxidative stress but more resistant to antibiotics under anoxic conditions. Additionally, many, though not all, patho-adaptive traits we assayed are insensitive to oxygen availability. Our results suggest that inferences about trait expression, especially those associated with the transition to chronic infection, depend on both the available oxygen and niche of origin of the strains being studied.

The Pseudomonas aeruginosa genome can change to adapt to different ecological niches. We compared four genomes from a Mexican hospital and 59 genomes from GenBank from different niches, such as urine, sputum, and environmental. The ST analysis showed that high-risk STs (ST235, ST773, and ST27) were present in the genomes of the three niches from GenBank, and the STs of Mexican genomes (ST167, ST2731, and ST549) differed from the GenBank genomes. Phylogenetic analysis showed that the genomes were clustering according to their ST and not their niche. When analyzing the genomic content, we observed that environmental genomes had genes involved in adapting to the environment not found in the clinics and that their mechanisms of resistance were mutations in antibiotic resistance-related genes. In contrast, clinical genomes from GenBank had resistance genes, in mobile/mobilizable genetic elements in the chromosome, except for the Mexican genomes that carried them mostly in plasmids. This was related to the presence of CRISPR-Cas and anti-CRISPR; however, Mexican strains only had plasmids and CRISPR-Cas. blaOXA-488 (a variant of blaOXA50) with higher activity against carbapenems was more prevalent in sputum genomes. The virulome analysis showed that exoS was most prevalent in the genomes of urinary samples and exoU and pldA in sputum samples. This study provides evidence regarding the genetic variability among P. aeruginosa isolated from different niches.

Human-imported pollutants could induce water black, changing microbial community structure and function. Employed 16S rRNA high-throughput sequencing, field-scale investigations and laboratory-scale experiments were successively conducted to reveal mechanistic insights into microbial community assembly and succession of black-odor waters (BOWs). In the field-scale investigation, livestock breeding wastewater (56.7 ± 3.2%) was the most critical microbial source. Moreover, fermentation (27.1 ± 4.4%) was found to be the dominant function. Combined with laboratory experiments, the critical environmental factors, such as total organic carbon (30–100 mg/L), ammonia nitrogen (2.5–9 mg/L), initial dissolved oxygen (2–8 mg/L) and chlorophyll a (0–90 mg/L), impacted the intensity of blackening. The differentiation of ecological niches within the microbial community played a significant role in driving the blackening speed. In laboratory-scale experiments, the microbial ecological niche determined the blackening timing and dominations of the stochastic processes in the microbial assembly process (88 - 51%). The three stages, including the anaerobic degradation stage, blackening stage and slow recovery stage, were proposed to understand the assembly of the microbial communities. These findings enhance our understanding of microorganisms in BOWs and provide valuable insights for detecting and managing heavily organic polluted waters. [Display omitted] • Environmental factors changed the intensity of blackening. • The differentiation of ecological niches drove the rate of blackening. • The three stages of microbial community dynamics were proposed. [ABSTRACT FROM AUTHOR]

To investigate the fishery community structure in spring at the early stage of construction of Tangshan Marine Ranching, in China. This study analyzed the relationship between species composition, diversity and community structure of fishery resources in marine ranching using survey data from March, April, and May 2017. The results showed that a total of 53 species of organisms occurred in the spring in the waters inside and outside the reef area of the marine pasture. Among them, 20 species of fish were among the chordates. 16 species of arthropods, including 6 species of shrimps and 8 species of crabs. Ten species of mollusks, including 6 species of snails. 5 species of echinoderms, 1 species of annelids, and 1 species of Cnidaria). The diversity index, evenness index and richness index outside the reef area of marine ranching in spring were greater than those in the reef area. According to cluster analysis and non-metric multidimensional scale ranking analysis, the biological communities inside and outside the reef area can be divided into four groups, with the similarity of the communities in the reef area being greater. The Abundance-Biomass Comparison curves (ABC curve) indicated that the biological communities within and outside of the reef had been moderately disturbed. The relative importance index and niche analysis demonstrated that there had been sufficient bait in the reef area, and the ecological structure of the marine ranching was taking shape. [ABSTRACT FROM AUTHOR]

The deep-sea hydrothermal vent ecosystem is one of the extreme chemoautotrophic environments. Shinkaicaris leurokolos Kikuchi and Hashimoto, 2000, and Alvinocaris longirostris Kikuchi and Ohta, 1995, are typically co-distributed and closely related alvinocaridid shrimps in hydrothermal vent areas with different ecological niches, providing an excellent model for studying the adaptive evolution mechanism of animals in the extreme deep-sea hydrothermal vent environment. The shrimp S. leurokolos lives in close proximity to the chimney vent discharging high-temperature fluid, while A. longirostris inhabits the peripheral areas of hydrothermal vents. In this study, full-length transcriptomes of S. leurokolos and A. longirostris were generated using a combination of single-molecule real-time (SMRT) and Illumina RNA-seq technology. Expression analyses of the transcriptomes showed that among the top 30% of highly expressed genes of each species, more genes related to sulfide and heavy metal metabolism (sulfide: quinone oxidoreductase, SQR; persulfide dioxygenase, ETHE1; thiosulfate sulfurtransferase, TST, and ferritin, FRI) were specifically highly expressed in S. leurokolos, while genes involved in maintaining epibiotic bacteria or pathogen resistance (beta-1,3-glucan-binding protein, BGBP; endochitinase, CHIT; acidic mammalian chitinase, CHIA, and anti-lipopolysaccharide factors, ALPS) were highly expressed in A. longirostris. Gene family expansion analysis revealed that genes related to anti-oxidant metabolism (cytosolic manganese superoxide dismutase, SODM; glutathione S-transferase, GST, and glutathione peroxidase, GPX) and heat stress (heat shock cognate 70 kDa protein, HSP70 and heat shock 70 kDa protein cognate 4, HSP7D) underwent significant expansion in S. leurokolos, while CHIA and CHIT involved in pathogen resistance significantly expanded in A. longirostris. Finally, 66 positively selected genes (PSGs) were identified in the vent shrimp S. leurokolos. Most of the PSGs were involved in DNA repair, antioxidation, immune defense, and heat stress response, suggesting their function in the adaptive evolution of species inhabiting the extreme vent microhabitat. This study provides abundant genetic resources for deep-sea invertebrates, and is expected to lay the foundation for deep decipherment of the adaptive evolution mechanism of shrimps in a deep-sea chemosynthetic ecosystem based on further whole-genome comparison. [ABSTRACT FROM AUTHOR]

The Lichtenfelder's Tiger Gecko, Goniurosaurus lichtenfelderi is currently known only from northern Vietnam and southern China. Because of its restricted distribution, the species is potentially threatened by extinction due to anthropogenic impacts. Recently, the species has been listed in the IUCN Red List of Threatened Species as "Vulnerable" and included in CITES Appendix II and the Vietnam Governmental Decree – Group IIB. However, conservation activities to safeguard wild populations of G. lichtenfelderi have not yet been implemented due to a lack of detailed information about the population status and its ecological requirements. In this study, the micro-habitat use of G. lichtenfelderi was assessed. As a result of our field surveys, we found this species in evergreen forest areas with a high percentage of vegetation coverage and in close proximity to medium or small stream sections with rocky shelters on granitic formations. Canopy coverage, three micro-climatic variables (air, substrate temperature and humidity), weather condition and substrate type were the most important characteristics explaining the variation in the micro-habitat use of G. lichtenfelderi. Coupled with a macro-ecological (climate niche) approach, the complex niches of G. lichtenfelderi were defined by comparing them between two geographically distant populations in island and mainland sites. We found high similarities in macro-climatic and micro-habitat niches between the island and mainland populations of G. lichtenfelderi. Based on the ecological information, we recommend conservation actions to protect the core refugia of G. lichtenfelderi and reduce negative influences of anthropogenic impacts on wild populations in the future. [ABSTRACT FROM AUTHOR]

Aim: The purpose of this research was to use environmental variables for predicting the probability of Hemiscorpius lepturus existence in the provinces where situated in the west of the Zagros Mountains. Materials and Methods: In this study, 64 occurrence records of the H. lepturus were extracted from the published documents available in electronic databases. MaxEnt model was used for predicting the ecological niches of this species. Normalized difference vegetation index (NDVI) and 19 climatic variables were used as the environmental variables affecting the distribution of this scorpion. The Jackknife test in the model was used to indicate the importance of variables to predict the probability of the presence of the studied species. The logistic threshold that was evaluated using a logistic regression algorithm showed the converting of the probability model into a binary model. The model was evaluated by area under the curve (AUC). The probability presence map of this scorpion was then prepared in ArcGIS 10.5 Software. Results: The results of the analysis showed that the most important environmental factor on the distribution of H. lepturus was the maximum temperature of the warmest month (Bio5) with a contribution rate of 43% and permutation importance of 8%. The Jackknife test revealed that NDVI did not gain any value when it used independently in the model. The logistic threshold was reported 0.255 for the maximum test sensitivity plus specificity. The AUC of the model was 0.7698, shows an acceptable value for model validity. Overall the hot spots for this toxic scorpion seem to be in Khuzestan, Lorestan, and Ilam Provinces of the studied area. Conclusion: Regarding our findings, MaxEnt algorithm, in combination with geographic information system contributed to revealing the effects of environmental variables on the probability of H. lepturus presence in the west of Zagros Mountains. These visualized maps as a warning alarm can be helpful to policymakers for managing, controlling, and monitoring the scorpionism in high-risk areas.

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Dead species remain dead. The diversity record of life is littered with examples of declines and radiations, yet no species has ever re-evolved following its true extinction. In contrast, functional traits can transcend diversity declines, often develop iteratively and are taxon-free allowing application across taxa, environments and time. Planktonic foraminifera have an unrivaled, near continuous fossil record for the past 200 million years making them a perfect test organism to understand trait changes through time, but the functional role of morphology in determining habitat occupation has been questioned. Here, we use single specimen stable isotopes to reconstruct the water depth habitat of individual planktonic foraminifera in the genus Subbotina alongside morphological measurements of the tests to understand trait changes through the Middle Eocene Climatic Optimum [MECO: ∼40 Myr ago (mega annum, Ma)]. The MECO is a geologically transient global warming interval that marks the beginning of widespread biotic reorganizations in marine organisms spanning a size spectrum from diatoms to whales. In contrast to other planktonic foraminiferal genera, the subbotinids flourished through this interval despite multiple climatic perturbations superimposed on a changing background climate. Through coupled trait and geochemical analysis, we show that Subbotina survival through this climatically dynamic interval was aided by trait plasticity and a wider ecological niche than previously thought for a subthermocline dwelling genus supporting a generalist life strategy. We also show how individually resolved oxygen isotopes can track shifts in depth occupancy through climatic upheaval. During and following the MECO, temperature changes were substantial in the thermocline and subthermocline in comparison to the muted responses of the surface ocean. In our post-MECO samples, we observe restoration of planktonic foraminifera depth stratification. Despite these changing temperatures and occupied depths, we do not detect a contemporaneous morphological response implying that readily available traits such as test size and shape do not have a clear functional role in this generalist genus. Modern imaging measurement technologies offer a promising route to gather more informative morphological traits for functional analysis, rather than the traditional candidates that are most easily measured.

The architecture of rice plant represents important and complex agronomic traits, such as panicles morphology, which directly influence the microclimate of rice population and consequently grain yield. To enhance yield, modification of plant architecture to create new hybrid cultivars is considered a sustainable approach. The current study includes an investigation of yield and microclimate response index under low to high plant density of two indica hybrid rice R498 (curved panicles) and R499 (erect panicles), from 2017 to 2018. The split-plot design included planting densities of 11.9–36.2 plant/m2. The results showed that compared with R498, R499 produced a higher grain yield of 8.02–8.83 t/ha at a higher planting density of 26.5–36.2 plant/m2. The response index of light intensity and relative humidity to the planting density of R499 was higher than that of R498 at the lower position of the rice population. However, the response index of temperature to the planting density of R499 was higher at the upper position (0.2–1.4%) than at the lower position. Compared with R498, R499 at a high planting density developed lower relative humidity (78–88%) and higher light intensity (9900–15,916 lx) at the lower position of the rice population. Our finding suggests that erect panicles are highly related to grain yield microclimatic contributors under a highly dense rice population, such as light intensity utilization, humidity, and temperature. The application of erect panicle rice type provides a potential strategy for yield improvement by increasing microclimatic conditions in rice. [ABSTRACT FROM AUTHOR]

The diverse physicochemical conditions prevailing in the Arabian Sea are expected to result in marked spatial variations in heterotrophic flagellate (HF) and ciliate communities. Here, we report the environmental association of heterotrophic micro-eukaryotes, particularly the heterotrophic flagellates and ciliates, based on 18S rRNA gene survey in the region. High-throughput next-generation sequencing, using the V4 eukaryotic-specific primer, was employed to study the composition of these communities associated with low-O2 waters in both coastal and offshore settings. Canonical correspondence analysis (CCA) revealed a preference of the heterotrophic flagellates for nitrate- and nitrite-rich zones. Notably, the heterotrophic nanoflagellate genus Monosiga showed a strong positive correlation with NO3−, which suggests its potential denitrifying capability. Shannon's entropy analysis revealed a higher HF diversity in the hypoxic waters of the open ocean (depth 103 m), whereas ciliates were more diverse at oxygenated coastal stations. The estuarine waters exhibited a low diversity of both ciliates and flagellates. The UPGMA clusters of heterotrophic flagellates and ciliates in suboxic waters of the open ocean oxygen minimum zone were distinct from those found at other sites. Overall, CCA revealed the important relationship between nitrite, nitrate, salinity and chlorophyll a, which could be important factors for the partitioning of different ecological niches for specific HF and ciliate communities in the Arabian Sea. The community of heterotrophic protists that can adapt to varying biogeochemical regimes has been identified. [ABSTRACT FROM AUTHOR]

In recent years, Japanese quince (Chaenomeles japonica) plantations in Latvia have increased. Interest in breeding Japanese quince is also known in other European countries and Russia. The occurrence and harmfulness of fungal diseases have become increasingly significant. However, there is a lack of overall information in the literature about the diversity of fungi afflicting C. japonica. In our study, we aimed to determine the diversity of fungi associated with C. japonica in Latvia, with the possibility of identifying the fungi that are most characteristically associated with certain parts of the plant. Our research was conducted from 2017 to 2019 in eight Japanese quince plantations in Latvia. Samples of plant parts with disease symptoms were collected. Pure cultures of fungi were obtained and identified using ITS region sequencing. We determined the relative density of identified genera of fungi, which were grouped using hierarchical cluster analysis depending on the plant part from which they were found. Various disease-like symptoms were observed and described. A total of 538 isolates of fungi were obtained that belong to 36 genera and represent different ecological niches. Fusarium, Alternaria, Botrytis, and Sarocladium were the genera most frequently found during our study. The number of identified cases of fungal genera differed depending on the part of the plant from which the fungi were obtained. However, it is not possible to relate a specific genus of fungus to only one certain part of a plant. Further research is needed to clarify the pathogenicity of detected fungi and the composition of species in the detected genera of fungi.

The Sechium P. Br. genus composed of 11 species, which originated from the mountainous regions of Mesoamerica, have been domesticated and diversified. These species are clustered in two large groups: the Mexican clade and the Central American clade. Morphological and molecular studies have shown that species of the Mexican clade are formed through interspecific hybridizations and genetic flow, with the exception of S. mexicanum, which is strongly linked to the genus Sicyos. The objective of this review was to analyze the phylogenetics of Sechium based on morphological and molecular studies, which contributed to taxonomic knowledge and utilization, thereby favoring its conservation and improvement. The Central American clade is well supported with molecular data, but not so with morphological data. The species in this clade were geographically isolated and endemic. S. edule and S. tacaco are exploited species in the agricultural and industrial sectors, and both have an extensive genetic and phenotypic diversity that has allowed them to diversify and expand into different ecological niches. Finally, the Central American species of Sechium thrive in adverse environments of temperatures of mesophyll forest and high relative humidity, with characteristics that can give resistance to frosts and phytopathogenic agents, as well as cultivated species of this genus.

Fungal entomopathogens are largely facultative parasites and play an important role in controlling the density of insect populations in nature. A few species of these fungi have been used for biocontrol of insect pests. The pattern of the entomopathogen competition for insect individuals is still elusive. Here, we report the empirical competition for hosts or niches between the inter- and intra-species of the entomopathogens Metarhizium robertsii and Beauveria bassiana. It was found that the synergistic effect of coinfection on virulence increase was not evident, and the insects were largely killed and mycosed by M. robertsii independent of its initial co-inoculation dosage and infection order. For example, >90% dead insects were mycosed by M. robertsii even after immersion in a spore suspension with a mixture ratio of 9:1 for B. bassiana versus M. robertsii. The results thus support the pattern of competitive exclusion between insect pathogenic fungi that occurred from outside to inside the insect hosts. Even being inferior to compete for insects, B. bassiana could outcompete M. robertsii during co-culturing in liquid medium. It was also found that the one-sided mycosis of insects occurred during coinfection with different genotypic strains of either fungi. However, parasexual recombination was evident to take place between the compatible strains after coinfection. The data of this study can help explain the phenomena of the exclusive mycosis of insect individuals, but co-occurrence of entomopathogens in the fields, and suggest that the synergistic effect is questionable regarding the mixed use of fungal parasites for insect pest control. [ABSTRACT FROM AUTHOR]