High Taxonomic Diversity Research Articles

Cursorial ecomorphology and temporal patterns in theropod dinosaur evolution during the mid-Cretaceous.

Coelurosauria, including modern birds, represents a successful group of theropod dinosaurs that established a high taxonomic diversity and significant morphological modifications. In the evolutionary history of this group, a specialized foot morphology, the arctometatarsus, evolved independently in several lineages and has been considered an adaptation for cursoriality. While its functional significance has been extensively studied, the temporal pattern of this parallel evolution, as well as its origin and influencing factors, remains largely unresolved. Here, we show the temporal evolution of cursorial traits, including the arctometatarsus and hind limb proportions. Our study reveals that the proportional elongation of distal hind limb segments preceded the evolution of the arctometatarsus in ornithomimosaurs and oviraptorosaurs. In contrast, in tyrannosauroids, alvarezsaurs and troodontids, the proportional elongation of the tibia and metatarsals occurred in parallel with the acquisition of the arctometatarsus. The evolutionary history of the arctometatarsus further highlights the presence of a phylogenetic constraint outside Coelurosauria, as this foot specialization is restricted to members of this group. Finally, our date estimation, based on compiled evolutionary patterns, demonstrates that these cursorial traits emerged during the mid-Cretaceous (93-120 Ma), suggesting selection on theropod locomotor performance throughout this interval.

Thriving in the heat: How high temperatures and habitat disturbance shape odonate taxonomic and functional diversity in the tropics

Abstract Because insects are unable to regulate their body temperatures, they are vulnerable to rising temperatures and habitat disturbances that limit access to optimal microhabitats. This study examines how these factors affect the taxonomic and functional diversity of Odonata insects (Anisoptera and Zygoptera) in a tropical dry landscape. We assessed taxonomic diversity using Hill numbers (0D, 1D, 2D) and functional diversity in preserved and disturbed sites within a tropical dry forest. Functional diversity was measured using the standardised effect size (SES) of functional richness, evenness, divergence and community‐weighted means (CWMs), focusing on traits related to heat tolerance and resource acquisition (body colouration and size). Taxonomic diversity was positively related to high temperatures and vegetation in Anisoptera, with no relation for Zygoptera. The SES of functional richness for Zygoptera was higher in preserved areas, while anisopterans showed no changes. Only Anisoptera showed a negative correlation between functional evenness and maximum temperatures. Functional divergence in both suborders was higher in disturbed areas. In Anisoptera, the CWM of body colour lightness was higher in disturbed sites, but neither environmental factor affected the CWM of body size in either suborder. While disturbance limited trait variability in zygopterans, it favoured species with extreme traits in both suborders. Reduced trait variability in preserved sites may have affected adaptability to future disturbances. Our study highlights that Odonata communities maintain stable taxonomic diversity despite disturbances, but shifts in functional diversity could compromise their resilience and ecological roles.

High prevalence of <em>Trypanosoma</em> infection in Iberian green frogs (<em>Pelophylax perezi</em>) and evidence of a negative relationship between blood parasites and two indices of frog body condition

Trypanosoma commonly parasitizes anuran hosts but very few studies have investigated ecological relationships in multiparasitized amphibians. We analysed a sample of 29 adult Iberian green frogs (Pelophylax perezi) from a monitored population in central Spain and found that 28 of these individuals (96.5%) were infected with blood parasites. The protozoa genera Lankesterella (Apicomplexa: Eimeriorina) (72.4%) and Trypanosoma (Euglenozoa: Trypanosomatida) (69%) had the highest prevalence, followed by an intraerythrocytic bacteria of the genus Aegyptianella (Pseudomonadota: Rickettsiales) (31.0%). We also report an infection by hematic microfilariae (Nematoda: Spirurida) (6.8%), which to our knowledge represents the first documented case in Iberian amphibians. Infections with more than one parasite type occurred in 62.1% of the frogs. A multimodel inference approach indicated that the infection intensities of Trypanosoma and Aegyptianella were the most important predictors, both negatively affecting the body condition of the frogs. Furthermore, the number of leeches that frogs had when captured showed a strong positive association with Trypanosoma infection intensity. This suggests that leeches act as primary vectors for Trypanosoma. Our results revealed a high taxonomic diversity of blood parasites in green frogs, thus contributing to expand our knowledge of the biodiversity of Mediterranean wetlands and highlighted the potential negative effects of certain infections on the fitness of these amphibian hosts.

A Model of Southern Sikhote-Alin Liverwort Flora and a New Approach to Analyze the Altitudinal Distribution Patterns in the Zov Tigra National Park (South of the Russian Far East, Temperate Pacific Asia)

The liverwort flora in Zov Tigra National Park in southern Sikhote-Alin (Primorye Territory, south of the Russian Far East), which has one of the richest regional floras, was studied to assess its taxonomic diversity, and analyzed using a new approach to determine altitudinal distribution patterns. This new approach is based on probabilistic models of the altitudinal distribution of individual taxa proposed for identifying altitudinal groups of species. This method can be used to analyze patterns of the distribution of species of various taxonomic groups in cases where a sufficiently representative dataset is available and may be especially relevant in regions where altitudinal zonation is not obvious or changes in the altitudinal fractions of the dominant vegetation are too continuous. The proposed method revealed three altitudinal groups that were more clearly differentiated than groups of taxa based on altitudinal vegetation belts. Based on the obtained results, the most important bioclimatic indices correlated with the altitudinal distribution of liverworts were identified: annual mean temperature (BIO1), annual precipitation (BIO12), isothermality (BIO3), and factors associated with the temperature and amount of precipitation during the warmest period of the year, including the maximum temperature of the warmest month (BIO5), the mean temperature of the wettest quarter (BIO8), the mean temperature of the warmest quarter (BIO10), precipitation during the wettest month (BIO13), precipitation during the wettest quarter (BIO16), and precipitation during the warmest quarter (BIO18). This study reports 130 species, 1 variety, and 1 subspecies. Pseudolophozia debiliformis and Scapania praetervisa are newly recorded for Sikhote-Alin and the Primorye Territory. Diplophyllum albicans and Cephaloziella rubella are newly reported for the Primorye Territory. The national park liverwort flora can be classified as boreal–temperate circumpolar–East Asian. Given the high taxonomic diversity and coverage of all altitudinal zones represented in the region, the liverwort flora in Zov Tigra National Park can serve as a model for all liverwort floras in southern Sikhote-Alin.

Alkalothermophilic Iron-Reducing Bacteria of the Goryachinsk Thermal Water Basin

A study of iron-reducing prokaryotes that use the poorly crystalline mineral ferrihydrite as an electron acceptor revealed their widespread occurrence on the planet. However, the ability of iron reducers to develop under polyextreme conditions (at elevated values of pH and temperature) has not been previously demonstrated. To confirm the existence of alkalothermophilic iron reducers, we studied the water and sediment samples from the Goryachinsk nitrogen-rich thermal water basin. These springs are associated with young tectonic fractures in the Baikal rift zone; their water is characterized by low salinity, alkaline pH (8.8‒9.2) and temperature of 53‒55°C. Enrichment cultures reducing synthesized ferrihydrite were obtained by adding this mineral to the water and sediment samples from the Goryachinsk thermal springs, followed by anaerobic incubation at 50 and 55°C. The 16S rRNA gene profiling of the water and sediment samples and of the primary enrichment cultures revealed high taxonomic diversity, almost exclusively represented by bacterial taxa. Subsequent transfers with ferrihydrite and organic acids or hydrogen as electron donors resulted in stable enrichment cultures of organo- and lithotrophic alkalothermophilic iron reducers. Members of the genus Parvivirga, one of the first cultured representatives of the OPB41 group (now the order Anaerosomatales, phylum Actinomycetota), constituted 30 to 50% of the total abundance.

Functional Diversity of Macroinvertebrate Communities in River Nature Reserves of Spain

In recent decades, aquatic ecosystems have suffered a series of impacts that have made them some of the most threatened ecosystems on a global scale. So, protection measures are needed to conserve the biodiversity we find in some of the less impacted ecosystems. In the Spanish legislation, a category arose for this purpose in lotic ecosystems, the River Natural Reserve (RNR). In this work, we analyse the taxonomic and functional diversity of 145 macroinvertebrate biocoenoses from 128 different RNRs belonging to 10 different basins and representing 18 typologies. Most of the analysed biocoenoses have an overall high taxonomic diversity, with some exceptions corresponding to particular reaches suffering occasional disturbances or with very special conditions. An intermediate functional homogeneity has been also detected, related to a relatively low average functional richness. We also found medium levels of functional evenness, a high functional divergence, and low functional dispersion and Rao index values, the latter supporting similarities among taxa in functional terms. In our studied systems, there is high taxa turnover, but functional turnover is very low. This means that most of the trait dissimilarity between taxa is found within a community, but not among communities, though there are relatively strong dissimilarities in community composition. Our results support the fact that the RNRs are protecting communities of great diversity, not only taxonomic, but also functional, which contributes to the proper functioning of the ecosystems found in these stream reaches. Thus, the analysis of the functional diversity of the communities, as in the present approach, should be implemented to identify and prioritize protection of reaches with higher functional diversity, where enhanced ecosystem functioning can be expected.

Functional diversity and resilience of bivalves after the Permian-Triassic mass extinction

The Permian-Triassic mass extinction was the largest extinction event in the Phanerozoic eon, with profound taxonomic and ecological effects on the ecosystem function. Functional diversity, a facet of biodiversity, could reflect the ecosystem function and stability. Although previous studies have shown that the functional richness of global marine organisms was decoupled from their taxonomic diversity during the mass extinctions, the evolution of functional diversity during the Permian-Triassic mass extinction and its aftermath is still under debate. The ecologically diverse clade bivalves may be more representative for understanding the evolution of functional diversity. To investigate the evolutionary dynamics of the functional diversity of bivalves, a global bivalve dataset of 8929 occurrences from the latest Permian to the Late Triassic was constructed. Functional richness, functional evenness, and functional redundancy were calculated to reflect the functional diversity in this study. Our results showed that the functional richness of bivalves was slightly affected by the Permian-Triassic mass extinction, decoupled from the significant decrease in taxonomic diversity. Meanwhile, a decrease in functional redundancy and an increase in functional evenness were observed after the mass extinction. In addition, bivalves showed high resilience to the mass extinction by maintaining the ecospace and reducing the functional redundancy. The high taxonomic diversity, high functional richness, high functional redundancy and relatively higher proportion of infaunal bivalves during the Late Triassic indicate that the Mesozoic marine revolution was already underway.

Insights into the occurrence of phylosymbiosis and co-phylogeny in the holobionts of octocorals from the Mediterranean Sea and Red Sea

BackgroundCorals are the foundational species of coral reefs and coralligenous ecosystems. Their success has been linked to symbioses with microorganisms, and a coral host and its symbionts are therefore considered a single entity, called the holobiont. This suggests that there may be evolutionary links between corals and their microbiomes. While there is evidence of phylosymbiosis in scleractinian hexacorals, little is known about the holobionts of Alcyonacean octocorals.Results16S rRNA gene amplicon sequencing revealed differences in the diversity and composition of bacterial communities associated with octocorals collected from the mesophotic zones of the Mediterranean and Red Seas. The low diversity and consistent dominance of Endozoicomonadaceae and/or Spirochaetaceae in the bacterial communities of Mediterranean octocorals suggest that these corals may have a shared evolutionary history with their microbiota. Phylosymbiotic signals were indeed detected and cophylogeny in associations between several bacterial strains, particularly those belonging to Endozoicomonadaceae or Spirochaetaceae, and coral species were identified. Conversely, phylosymbiotic patterns were not evident in Red Sea octocorals, likely due to the high bacterial taxonomic diversity in their microbiota, but cophylogeny in associations between certain coral and bacterial species was observed. Noteworthy were the associations with Endozoicomonadaceae, suggesting a plausible evolutionary link that warrants further investigations to uncover potential underlying patterns.ConclusionsOverall, our findings emphasize the importance of Endozoicomonadaceae and Spirochaetaceae in coral symbiosis and the significance of exploring host-microbiome interactions in mesophotic ecosystems for a comprehensive understanding of coral-microbiome evolutionary history.

Home range sizes and nychthemeral habitat uses by the Northern Shoveler (Spatula clypeata) on prenuptial stopovers in Vendée marshes, western France

The wetlands of Marais breton (MB) and Marais poitevin (MP) on the French Atlantic coast are commonly used by several duck species, especially as stopover sites during the prenuptial migration. Understanding the ecological requirements of Anatidae at spring stopover sites is important to define appropriate management actions that might have a carry over effect on the subsequent reproduction success. This study focused on the Northern Shoveler (Spatula clypeata), a species that regularly visits the two marshes during spring and fall migrations and is highly dependent on freshwater invertebrates as the food resource. Fifteen Northern Shovelers were equipped with GPS/GSM tags and monitored during their stopover in both marshes in 2020 and 2021. The aims of the study were to understand the habitat use on stopover sites and relate home range (HR) size with characteristics of the feeding habitats (such as freshwater invertebrates’ density and diversity). The HR area of the studied individuals was mainly constituted of ponds in MB (83% of the HR) and wet meadows in MP (71% of the HR). The Northern Shovelers equipped with tag spent more than 72 consecutive hours in 31 wetlands, using them during the day, at night or all day. The diurnal visited sites were deep ponds that were sparsely vegetated and dominated by microcrustaceans, whereas the nocturnal visited sites were wet meadows or ponds with high aquatic vegetation cover and high invertebrate taxonomic diversity. The 31 described sites appeared to be rich in freshwater invertebrates, with no significant difference in invertebrate densities between the diurnal and nocturnal sites. HR sizes were highly homogenous between the two study sites (MB and MP), between sexes or between age classes. In conclusion, according to this study, an appropriate HR for the Northern Shoveler at spring stopover is 8.49 ± 5.95 km² (mean ± standard error).

The problem of ammonoid substantiation of the Artinskian–Kungurian boundary in Western Verkhoyanie

Kungurian ammonoids had high taxonomic diversity, but were distinguished by an extremely high level of endemism and sharp geographic differentiation. Therefore, outside the regions containing the most important conodont taxa, the Artinskian-Kungurian boundary based on ammonoids must be established through indirect evidence due to the lack of common species with potential global stratotypes of the lower boundary of the Kungurian. A long-term study of the reference sections of the Echian and Tumarian regional stages and their ammonoids made it possible to change the understanding of the bio- and lithostratigraphy of the Artinskian-Kungurian boundary deposits of the Kuranakh structural-facies zone of Western Verkhoyanie. Clarification of the upper boundary of the Khabakh Formation in the stratotype section led to the fact that the ammonoids previously belonging to this formation began to be considered in the lower part of the Orol formation. They characterize the Paratumaroceras? sp. nov. biostratigraphic beds of the lower part of the Tumarian Regional Stage. At the current level of knowledge, the ammonoid substantiation of the Artinskian–Kungurian boundary in Verkhoyanie is difficult due to the existing hiatus corresponding to the Khabakh formation and its age analogues. However, the appearance at the base of the Tumarian Regional Stage of the first paragastrioceratids with a ventral sinus in transverse sculpture (Paratumaroceras? sp. nov.) suggests that the boundary in question is located near the base of the indicated regional stage or even combined with it. For further clearer identification of the Kungurian lower boundary in Verkhoyanie, new studies of the Echian–Tumarian boundary deposits in typical sections, independent of paleontology, are necessary. Such research should primarily include isotope-stratigraphic subdivision and high-precision U-Pb dating.

Taxonomic Diversity and Interannual Variation of Fish in the Lagoon of Meiji Reef (Mischief Reef), South China Sea.

Coral reef fish are important groups of coral reefs, which have great economic and ecological value. Meiji Reef is a representative tropical semi-enclosed atoll in the South China Sea, with rich fish resources. Based on the data from hand-fishing, line-fishing, and gillnet surveys of fish in Meiji Reef from 1998 to 2018, this study summarized the fish species list of Meiji Reef and analyzed the species composition, inclusion index at the taxonomic level (TINCL), genus-family diversity index (G-F index), average taxonomic distinctness index (Δ+), and variation in taxonomic distinctness (Λ+) and their changes. The results revealed that from 1998 to 2018, there were 166 reef-dwelling fish species on Meiji Reef, belonging to 69 genera, 33 families, and 11 orders, of which 128 species were from 20 families of Perciformes, accounting for 77.10% of the total cataloged species. Regarding the dependence of fish on coral reefs, there were 155 reef-dependent species or resident species (accounting for 93.37%) and 11 reef-independent species or wandering species (accounting for 6.63%). The TINCL of the order, families, and genus of fish in Meiji Reef were very high. The genus diversity index (G index), family diversity index (F index), and G-F index of fish in Meiji Reef were very high, and the G index of fish in Meiji Reef in 1998-1999 was higher than that in 2016-2018. The Δ+ and Λ+ values of fish in Meiji Reef from 1998 to 2018 were 56.1 and 148.5, respectively. Compared with 1998-1999, Δ+ and Λ+ of fish increased during 2016-2018, reflecting that the relatives of fish in Meiji Reef became further distant, and the uniformity of taxonomic relationships among species decreased. The research findings indicated that fish exhibited a high taxonomic diversity in Meiji Reef; however, it also revealed significant fluctuations in the fish diversity of Meiji Reef over an extended period, emphasizing the urgent need for timely protection measures. This investigation significantly contributes to our comprehension of the intricate dynamics governing fish species within Meiji Reef and holds broader implications for biodiversity conservation in tropical marine ecosystems.

Тaxonomic diversity of phytoplankton of fish ponds of Lviv Region

he article presents the results of research on the taxonomic diversity and ecological characteristics of phytoplankton in fish ponds of Lviv region. It was found that the phytoplankton of the studied water bodies was characterized by high taxonomic diversity and was represented by 170 species and intraspecific taxa belonging to 95 genera, 52 families, 29 orders, 13 classes and 7 systematic divisions. The dominant group of the floristic composition were Chlorophyta (49 – 64% of the total number of revealed species), the subdominants were Bacillariophyta (11 – 15%), Euglenozoa 7 – 20%) and Cyanobacteria 5 – 12%). Coefficients of species similarity according to Serensen (Ks = 0.620.83) and Kendel's rank correlation for leading families (τ = 0.540.73) and genera (τ = 0.410.70) were high that indicates the similarity of the species composition of algal communities of different farms. The analysis of the ecological characteristics of algae showed that planktonic 33 – 38%) forms predominated in phytoplankton in terms of biotope distribution. Plankton-benthic, epiphytic forms were of secondary importance, accounting for 26 – 29%) and 20 – 29%) of the total number of species with a known biotope distribution, respectively. Slow-flowing forms dominated in terms of rheophilicity 79 – 88%), in terms of salinity 82 – 91%) and relation to pH 73 – 86%)  indifferent species. The main share of phytoplankton saprobic indicator species was formed by β-mesosaprobes 51 – 59%) and o-α-mesosaprobes 17 – 19%), which characterize these water bodies as those with a moderate level of organic pollution.

Sugar assimilation underlying dietary evolution of Neotropical bats

Dietary specializations in animals lead to adaptations in morphology, anatomy and physiology. Neotropical bats, with their high taxonomic and trophic diversity, offer a unique perspective on diet-driven evolutionary adaptations. Here we assess the metabolic response to different dietary sugars among wild-caught bats. We found that insectivorous bats had a pronounced metabolic response to trehalose, whereas bats with nectar and fruit-based diets showed significantly higher blood glucose levels in response to glucose and sucrose, reaching levels over 750 mg dl−1. The genomic analysis of 22 focal species and two outgroup species identified positive selection for the digestive enzyme trehalase in insect eaters, while sucrase–isomaltase showed selection in lineages with omnivorous and nectar diets. By examining anatomical and cellular features of the small intestine, we discovered that dietary sugar proportion strongly impacted numerous digestive traits, providing valuable insight into the physiological implications of molecular adaptations. Using hybridization chain reaction (HCR) RNA fluorescence in situ hybridization, we observed unusually high expression in the glucose transporter gene Slc2a2 in nectar bats, while fruit bats increased levels of Slc5a1 and Slc2a5. Overall, this study highlights the intricate interplay between molecular, morphological and physiological aspects of diet evolution, offering new insights into the mechanisms of dietary diversification and sugar assimilation in mammals.

Ревизия Lepidoziaceae (Hepaticae) для российского Дальнего Востока II. Lepidozia и Kurzia

Kurzia and Lepidozia are revised for the Russian Far East. The identification keys, morphological descriptions, line drawings and lifetime photographs of species, ecological conditions and the clarified distribution within the region are provided. In general, the Russian Far East seems too cold region for high taxonomic diversity of the members of the family; nevertheless, the taxonomic diversity of Lepidoziaceae here is higher than in other regions of Russia.

Diversity-enhanced canopy space occupation and leaf functional diversity jointly promote overyielding in tropical tree communities

Understanding the mechanisms that drive biodiversity-productivity relationships is critical for guiding forest restoration. Although complementarity among trees in the canopy space has been suggested as a key mechanism for greater productivity in mixed-species tree communities, empirical evidence remains limited. Here, we used data from a tropical tree diversity experiment to disentangle the effects of tree species richness and community functional characteristics (community-weighted mean and functional diversity of leaf traits) on canopy space filling, and how these effects are related to overyielding. We found that canopy space filling was largely explained by species identity effects rather than tree diversity effects. Communities with a high abundance of species with a conservative resource-use strategy were those with most densely packed canopies. Across monocultures and mixtures, a higher canopy space filling translated into an enhanced wood productivity. Importantly, most communities (83 %) produced more wood volume than the average of their constituent species in monoculture (i.e. most communities overyielded). Our results show that overyielding increased with leaf functional diversity and positive net biodiversity effects on canopy space filling, which mainly arose due to a high taxonomic diversity. These findings suggest that both taxonomic diversity-enhanced canopy space filling and canopy leaf diversity are important drivers for overyielding in mixed-species forests. Consequently, restoration initiatives should promote stands with functionally diverse canopies by selecting tree species with large interspecific differences in leaf nutrition, as well as leaf and branch morphology to optimize carbon capture in young forest stands.

Spatiotemporal diversity of wild bee communities (Hymenoptera, Apoidea) in grassland ecosystems in semi-arid climate of North Africa (Algeria)

ABSTRACT In order to improve our knowledge on the biodiversity of wild bee communities in Algerian grasslands, two stations (El-Kouif and Gourigueur) belonging to Tebessa region were chosen. The current study provides data on the diversity and the structure of this taxonomic group in a semi-arid steppe in Northeastern Algeria. Wild bee alpha and beta diversity were investigated through the utilisation of diverse parameters such as species richness, occurrence, diversity indices, rarefaction curves, similarity indices. In total, 411 individuals of 14 genera and 46 species were collected. The most abundant species was Eucera nigrilabris (Apidae) with 69 individuals (16.79% of the total). The collected species were dominated by common taxa (17 species, 36.95% of the total). The GLM tests showed that the temporal variations of the abundance values (N) and the species richness (S) of wild bees were statistically significant. Overall, the most visited plant species was Eruca vesicaria (Brassicaceae) (N = 168, S = 24). Two types of species were distinguished in the present study, species foraged a wide range of plant and species foraged only one plant species. The wild bee communities showed high taxonomic diversity in grasslands situated in semi-arid steppe.

Organic geochemistry, sedimentology and palaeontology of the Khatyspyt Formation, Arctic Siberia: Towards an integrated view of Ediacaran biofacies

The terminal Ediacaran Khatyspyt Lagerstätte (ca. 550–544 Ma) of Arctic Siberia has been a prime target for geobiological research. Previous evidence suggested that Ediacaran macroscopic soft-bodied organisms could be highly sensitive to sedimentary processes and various environmental factors such as water column stratification and seawater redox-conditions. By integrating organic geochemistry, sedimentology, and palaeontology of the Khatyspyt Formation, we identified three biofacies. The most proximal Longifuniculum biofacies consists of outer- to mid-ramp debris flow deposits and is characterised by a high taxonomic diversity and biomarker proxies pointing to a non-stratified non-euxinic water column. The most distal Aspidella biofacies comprises outer-ramp thin-bedded calcareous turbidites and is also marked by a high taxonomic diversity, although the associated biomarker proxies provide evidence for a stratified euxinic environment. Transient between those is the Nenoxites biofacies, consisting of outer- to mid-ramp debris flow deposits and characterised by a low taxonomic diversity, with biomarker proxies indicating redox instability. This systematic pattern suggests that the distribution of Ediacaran organisms was influenced by a heterogenous redox landscape. More specifically, the highest diversity of benthic soft-bodied organisms, including the iconic Charnia masoni, appears in stratified euxinic environments, while the highest diversity of macroalgae is found in non-stratified settings. The occurrence of a complex Ediacaran community in a stratified euxinic environment suggests that anoxia might have driven ecological differentiation of organisms, and that heterogeneous and dynamic redox landscapes were far more significant in early animal evolution than hitherto appreciated.

Absence of a pancreatic microbiome in intraductal papillary mucinous neoplasm

ObjectiveThis study aims to validate the existence of a microbiome within intraductal papillary mucinous neoplasm (IPMN) that can be differentiated from the taxonomically diverse DNA background of next-generation sequencing procedures.DesignWe...

Plankton and contour algal communities in the ukrainian section of the Western Bug River and its tributaries

The taxonomic diversity of algae in the Western Bug River and its tributaries during the low-water summer-autumn season comprised 303 species (318 intraspecies taxa, ist) from 131 genera, 74 families, 45 orders, 16 classes and 8 phyla. Bacillariophyta dominated, Chlorophyta were recorded as subdominants. The phytoplankton taxonomic diversity included 140 ist, microphytobenthos – 191, phytoperiphyton – 172. The floristic nucleus of algal communities was formed by 17 families. In phytoplankton the highest rank belonged to Scenedesmaceae, while in contour algal communities – Naviculaceae. The highest floristic similarity was observed for microphytobenthos and phytoperiphyton, and the highest dissimilarity – for phytoplankton and phytoperiphyton. The spatial differentiation between contour and plankton communities during the low-water period, rather high similarity of their floristic structure indicate the unity of structural organization of algae from different ecological groups as an important component of biodiversity in the transboundary rivers. According to geographic distribution cosmopolites dominated; according to flow and oxygen regime – indifferents; according to pH preference – alkaliphilic and indifferent species; according to salinity preference – indifferent species; according to saprobiological characteristics – χ-ο- and β-mesosaprobic species. According to biotopic preference eurytopic and benthic forms prevailed. The dialectic unity between contour algal communities and phytoplankton to a great extent depends on morphometric and hydrological characteristics of the rivers under study. High taxonomic diversity, clearly marked spatial differentiation between planktonic and contour communities, interesting species of Bacillariophyta – all these features are indicative of the uniqueness and importance of algae in forming the biodiversity of the transboundary Western Bug River and its tributaries as the components of the EU hydrological network.

Evolutionary patterns of variations in chromosome counts and genome sizes show positive correlations with taxonomic diversity in tropical gingers.

Cytogenetic traits such as an organism's chromosome number and genome size are taxonomically critical as they are instrumental in defining angiosperm diversity. Variations in these traits can be traced to evolutionary processes such as polyploidization, although geographic variations across cytogenetic traits remain underexplored. In the pantropical monocot family Zingiberaceae (~1500 species), cytogenetic traits have been well documented; however, the role of these traits in shaping taxonomic diversity and biogeographic patterns of gingers is not known. A time-calibrated Bayesian phylogenetic tree was constructed for 290 taxa covering three of the four subfamilies in Zingiberaceae. We tested models of chromosome number and genome size evolution within the family and whether lineage age, taxonomic diversity, and distributional range explain the variations in the cytogenetic traits. Tests were carried out at two taxonomic ranks: within Zingiberaceae and within genus Hedychium using correlations, generalized linear models and phylogenetic least square models. The most frequent changes in chromosome number within Zingiberaceae were noted to be demi-polyploidization and polyploidization (~57% of the time), followed by ascending dysploidy (~27%). The subfamily Zingiberoideae showed descending dysploidy at its base, while Alpinioideae showed polyploidization at its internal nodes. Although chromosome counts and genome sizes did not corroborate with each other, suggesting that they are not equivalent; higher chromosome number variations and higher genome size variations were associated with higher taxonomic diversity and wider biogeographic distribution. Within Zingiberaceae, multiple incidences of polyploidization were discovered, and cytogenetic events appear to have reduced the genome sizes and increased taxonomic diversity, distributional ranges and invasiveness.