Diverse Taxa Research Articles

Accuracy of mutual predictions of plant and microbial communities vary along a successional gradient in an alpine glacier forefield.

Receding glaciers create virtually uninhabited substrates waiting for initial colonization of bacteria, fungi and plants. These glacier forefields serve as an ideal ecosystem for studying transformations in community composition and diversity over time and the interactions between taxonomic groups in a dynamic landscape. In this study, we investigated the relationships between the composition and diversity of bacteria, fungi, and plant communities as well as environmental factors along a successional gradient. We used random forest analysis assessing how well the composition and diversity of taxonomic groups and environmental factors mutually predict each other. We did not identify a single best indicator for all taxonomic and environmental properties, but found specific predictors to be most accurate for each taxon and environmental factor. The accuracy of prediction varied considerably along the successional gradient, highlighting the dynamic environmental conditions along the successional gradient that may also affect biotic interactions across taxa. This was also reflected by the high accuracy of predictions of plot age by all taxa. Next to plot age, our results indicate a strong importance of pH and temperature in structuring microbial and plant community composition. In addition, taxonomic groups predicted the community composition of each other more accurately than environmental factors, which may either suggest that these groups similarly respond to other not measured environmental factors or that direct interactions between taxa shape the composition of their communities. In contrast, diversity of taxa was not well predicted, suggesting that community composition of one taxonomic group is not a strong driver of the diversity of another group. Our study provides insights into the successional development of multidiverse communities shaped by complex interactions between taxonomic groups and the environment.

Trophic ecology of three marine polychaete species: Evidence from laboratory experiments using stable isotope (15N, 13C), fatty acid (NLFA) analyses, and C and N stoichiometry

Marine polychaetes are a highly diverse taxon with a large variety of different feeding modes. A proper identification of the different diets of polychaete species and their trophic position in the food web is crucial for understanding their interactions in marine ecosystems as well as marine community dynamics. Since gut content analyses and feeding experiments are difficult to conduct in marine habitats, other methods using biochemical tracers may contribute to a better understanding of the trophic ecology of marine polychaetes. Here, we conducted laboratory experiments and used a combination of stable isotope (13C, 15N) and neutral lipid fatty acid (NLFA) analyses, as well as C and N stoichiometry to determine the feeding habits of widely distributed marine polychaete species, such as Eurythoe complanata, Platynereis massiliensis, and Syllis malaquini. Additionally, the impact of starvation on the stable isotope signatures was analyzed. Our data show that the trophic ecology of the three species differs from each other. Stable isotope and fatty acid analyses indicate that (a) E. complanata is mainly feeding on algae, cyanobacteria and to a lesser extent on fungi, that (b) S. malaquini is mainly feeding on algae and bacteria and that (c) P. massiliensis is mainly feeding on algae, especially diatoms. An analysis of the C:N ratio of the respective annelid species and their potential food sources corroborated these results. The combination of stable isotope signatures, fatty acid markers and stoichiometry of carbon and nitrogen is a useful tool to identify the diet and trophic position of marine polychaete species and provides more results about their feeding habits and their position in marine food webs.

Current and lagged climate affects phenology across diverse taxonomic groups.

The timing of life events (phenology) can be influenced by climate. Studies from around the world tell us that climate cues and species' responses can vary greatly. If variation in climate effects on phenology is strong within a single ecosystem, climate change could lead to ecological disruption, but detailed data from diverse taxa within a single ecosystem are rare. We collated first sighting and median activity within a high-elevation environment for plants, insects, birds, mammals and an amphibian across 45 years (1975-2020). We related 10 812 phenological events to climate data to determine the relative importance of climate effects on species' phenologies. We demonstrate significant variation in climate-phenology linkage across taxa in a single ecosystem. Both current and prior climate predicted changes in phenology. Taxa responded to some cues similarly, such as snowmelt date and spring temperatures; other cues affected phenology differently. For example, prior summer precipitation had no effect on most plants, delayed first activity of some insects, but advanced activity of the amphibian, some mammals, and birds. Comparing phenological responses of taxa at a single location, we find that important cues often differ among taxa, suggesting that changes to climate may disrupt synchrony of timing among taxa.

First evidence of a monodominant (Englerodendron, Amherstieae, Detarioideae, Leguminosae) tropical moist forest from the early Miocene (21.73 Ma) of Ethiopia.

Many tropical wet forests are species-rich and have relatively even species frequency distributions. But, dominance by a single canopy species can also occur in tropical wet climates and can remain stable for centuries. These are uncommon globally, with the African wet tropics supporting more such communities than the Neotropics or Southeast Asia. Differences in regional evolutionary histories are implied by biogeography: most of Africa's monodominance-forming species are Amherstieae-tribe legumes; monodominance in Neotropical forests occur among diverse taxonomic groups, often legumes, but rarely Amherstieae, and monodominance in Southeast Asian forests occurs mostly among Dipterocarpaceae species. African monodominant forests have been characterized ecologically and taxonomically, but their deep-time history is unknown despite their significant presence and bottom-up ecological influence on diversity. Herein we describe fossil leaflets of Englerodendron mulugetanum sp. nov., an extinct species of the extant genus Englerodendron (Berlinia Clade, Amherstieae, Detarioideae) from the 21.73 Ma Mush Valley site in Ethiopia. We also document a detailed study of associated legume pollen, which originate from a single taxon sharing characters with more than one extant descendant. Taxonomically, the pollen is most comparable to that from some extant Englerodendron species and supports a likely affiliation with the Englerodendron macrofossils. The Mush Valley site provides the first fossil evidence of a monodominant tropical forest in Africa as represented by leaflets and pollen. Previous studies documented >2400 leaves and leaflets from localities at six stratigraphic levels spanning 50,000-60,000 years of nearly continuous deposition within seven meters of section; all but the basal level contain ≥ 50% E. mulugetanum leaflets. Modern leaf litter studies in African mixed vs. monodominant forests indicates the likelihood of monodominance in the forests that surrounded the Mush paleolake, particularly after the basal level. Thus, we provide an early case for monodominance within the Amherstieae legumes in Africa.

Naso-oropharyngeal microbiome from breast cancer patients diagnosed with COVID-19.

Due to immunosuppressive cancer therapies, cancer patients diagnosed with COVID-19 have a higher chance of developing severe symptoms and present a higher mortality rate in comparison to the general population. Here we show a comparative analysis of the microbiome from naso-oropharyngeal samples of breast cancer patients with respect to SARS-CoV-2 status and identified bacteria associated with symptom severity. Total DNA of naso-oropharyngeal swabs from 74 women with or without breast cancer, positive or negative for SARS-CoV-2 were PCR-amplified for 16S-rDNA V3 and V4 regions and submitted to massive parallel sequencing. Sequencing data were analyzed with QIIME2 and taxonomic identification was performed using the q2-feature-classifier QIIME2 plugin, the Greengenes Database, and amplicon sequence variants (ASV) analysis. A total of 486 different bacteria were identified. No difference was found in taxa diversity between sample groups. Cluster analysis did not group the samples concerning SARS-CoV-2 status, breast cancer diagnosis, or symptom severity. Three taxa (Pseudomonas, Moraxella, and Klebsiella,) showed to be overrepresented in women with breast cancer and positive for SARS-CoV-2 when compared to the other women groups, and five bacterial groups were associated with COVID-19 severity among breast cancer patients: Staphylococcus, Staphylococcus epidermidis, Scardovia, Parasegitibacter luogiensis, and Thermomonas. The presence of Staphylococcus in COVID-19 breast cancer patients may possibly be a consequence of nosocomial infection.

A Novel Lepidoptera bioassay analysed using a reduced GUTS model

Lepidopteran species can be both pests and also beneficial pollinators for agricultural crops. However, despite these important roles, the effects of pesticides on this diverse taxa are relatively understudied. To facilitate the assessment of pesticides and other chemical hazards on this taxa, we present a novel bioassay capable of testing chemical sensitivity to lepidopteran larvae through dietary exposure. We used Mamestra brassicae caterpillars as a model lepidopteran and tested their sensitivity for the organophosphate insecticide chlorpyrifos. We exposed larvae to an artificial diet spiked with chlorpyrifos and monitored survival over time, as well as weight change over a 96-hour exposure period. To test the repeatability and reliability of the developed bioassay, the experiment was repeated three times. The survival in time data collected enabled analysis with the General Unified Threshold of Survival (GUTS) model, recently recognized by EFSA as a ready-to-use tool for regulatory purposes. The GUTS modelling was used to derive a set of relevant toxicokinetic and toxicodynamic parameters relating to the larval response to exposure over time. We found that across the three repeats studies there was no more than a threefold difference in LC₅₀ values (13.1, 18.7 and 8.1 mg/Kg) at 48 h and fourfold difference at 96 h, highlighting the repeatability of the bioassay. We also highlighted the potential of the method to observe sub-lethal effects such as changes in weight. Finally, we discuss the applications of this new bioassay method to chemical risk assessments and its potential for use in other scenarios, such as mixture or pulsed exposure testing.

Environmental Factors Drive Chalcid Body Size Increases with Altitudinal Gradients for Two Hyper-Diverse Taxa.

Body size is the most essential feature that significantly correlates with insects' longevity, fecundity, metabolic rate, and sex ratio. Numerous biogeographical rules have been proposed to illustrate the correlation between the body sizes of different taxa and corresponding geographical or environmental factors. Whether the minute and multifarious chalcids exhibit a similar geographical pattern is still little known. In this research, we analyzed morphological data from 2953 specimens worldwide, including the two most abundant and diverse taxa (Pteromalidae and Eulophidae), which are both composed of field-collected and BOLD system specimens. We examined forewing length as a surrogate of body size and analyzed the average size separately for males and females using two methods (species and assemblage-based method). To verify Bergmann's rule, we included temperature, precipitation, wind speed and solar radiation as explanatory variables in a generalized linear model to analyze the causes of the size variation. We found that there was an increasing trend in the body size of Pteromalidae and Eulophidae with altitude. The optimal Akaike information criterion (AIC) models showed that larger sizes are significantly negatively correlated with temperature and positively correlated with precipitation, and the possible reasons for this variation are discussed and analyzed.

Both age and social environment shape the phenotype of ant workers

Position within the social group has consequences on individual lifespans in diverse taxa. This is especially obvious in eusocial insects, where workers differ in both the tasks they perform and their aging rates. However, in eusocial wasps, bees and ants, the performed task usually depends strongly on age. As such, untangling the effects of social role and age on worker physiology is a key step towards understanding the coevolution of sociality and aging. We performed an experimental protocol that allowed a separate analysis of these two factors using four groups of black garden ant (Lasius niger) workers: young foragers, old foragers, young nest workers, and old nest workers. We highlighted age-related differences in the proteome and metabolome of workers that were primarily related to worker subcaste and only secondarily to age. The relative abundance of proteins and metabolites suggests an improved xenobiotic detoxification, and a fuel metabolism based more on lipid use than carbohydrate use in young ants, regardless of their social role. Regardless of age, proteins related to the digestive function were more abundant in nest workers than in foragers. Old foragers were mostly characterized by weak abundances of molecules with an antibiotic activity or involved in chemical communication. Finally, our results suggest that even in tiny insects, extended lifespan may require to mitigate cancer risks. This is consistent with results found in eusocial rodents and thus opens up the discussion of shared mechanisms among distant taxa and the influence of sociality on life history traits such as longevity.

Toward new tools for biodiversity studies: the use of portable near-infrared spectroscopy combined with machine learning to identify species of Decapoda

Context Accuracy in species identification is a crucial factor for the quality of biodiversity studies and species management. Ensuring high accuracy is challenging for diverse taxonomic groups, including those with fishery importance such as Decapoda. Aims The objective of the present study was to use portable near-infrared spectroscopy combined with machine learning through a neural network (ANN) to identify species of Decapoda. Methods We propose an ANN application that rapidly and accurately emulates the results that would be obtained by a specialist. We used 124 specimens from seven marine Decapoda species as a dataset to fit the model. Key results The ANN was able to correctly learn (classify) all the patterns of the species (100% accuracy), with an overall mean probability of 0.97 ± 0.068. Conclusions The results obtained using portable near-infrared spectroscopy combined with machine learning (ANN) demonstrated that this method can be used with high accuracy to distinguish Decapoda species. Implications Studies aiming at comparisons among species may consider the use of this technique for the precise and inexpensive separation among species by non-specialists or for species that require the identification of a large number of individuals.

Abundance, geo-microbial role and community diversity of sulfate-reducing bacteria in tropical estuarine sediments

Sulfate-reducing bacteria (SRB), a diverse taxonomic group of anaerobic microorganisms that oxidize sulfur compounds as terminal electron acceptors, drive the key biogeochemical process of sulfate reduction. However, little is known about the diversity of SRB in tropical coastal habitats. Thus, the goal of this study is to explore and compare the community diversity of the Ashtamudi and Vembanad estuaries and evaluate the sedimentary sulfate reduction rate. The microbiome profiling of SRB was carried out using Next Generation Sequencing (NGS) techniques (Illumina sequencing) based on gene amplification of the dissimilatory sulfate reductase (dsr) enzyme to confirm the diversity and dominant taxa of SRB. The diversity of SRB represented by the Shannon alpha diversity index of the Ashtamudi estuary (6.55) was two-fold that of the Vembanad estuary. In the Vembanad estuary, the marine zone (4.09) harboured more diversity than the freshwater zone (1.825). Higher diversity and lower abundant taxa in the Ashtamudi estuary pointed out the presence of a rare biosphere that has not yet been studied. It was interesting to note that both estuaries have the same SRB phylum diversity. At the level of species, however, there was a noticeable difference. This differential diversity of SRB has an apparent influence on methane production during the breakdown of organic matter in addition to sulfate reduction. Several species of SRB have an important role in the biodegradation of persistent pollutants and the removal of heavy metals.

Discrepancies of fungi and plants in the pattern of beta-diversity with environmental gradient imply a comprehensive community assembly rule.

Beta-diversity partitioning has shown that the nestedness component is developed with environmental stress in a variety of taxa. However, soil fungal community may maintain its turnover components in contrast with the development of plants' nestedness component, and the potential causes remain unclear. To investigate the process of species turnover of soil fungi along a stress gradient in the Arctic, we divided species turnover component into sub-components; βsim_hete and βsim_homo representing species turnover with and without a change in the guilds, respectively. The results indicate that fungal communities maintain their turnover components unlike plant communities; however, their βsim_hete increased under stressful conditions. Additionally, GDM analysis showed that βsim_hete was mainly explained by stress gradient and plant nestedness, suggesting that functionality of soil fungi was ecologically filtered by environmental stress and plant community structure. The discordant trend of beta-diversity values between plant and fungi (i.e. development of plant nestedness and maintenance of fungal turnover) is possibly not caused by different assembly rules working in parallel on the two taxa, but according to an ecological rule that reflects plant-fungal interaction.

GERONIMO: A tool for systematic retrieval of structural RNAs in a broad evolutionary context.

While web-based tools such as BLAST have made identifying conserved gene homologs appear easy, genes with variable sequences pose significant challenges. Functionally important noncoding RNAs (ncRNA) often show low sequence conservation due to genetic variations, including insertions and deletions. Rather than conserved sequences, these RNAs possess highly conserved structural features across a broad phylogenetic range. Such features can be identified using the covariance models approach, which combines sequence alignment with a secondary RNA structure consensus. However, running standard implementation of that approach (Infernal) requires advanced bioinformatics knowledge compared to user-friendly web services like BLAST. The issue is partially addressed by RNAcentral, which can be used to search for homologs across a broad range of ncRNA sequence collections from diverse organisms but not across the genome assemblies. Here, we present GERONIMO, which conducts evolutionary searches across hundreds of genomes in a fully automated way. It provides results extended with taxonomy context, as summary tables and visualizations, to facilitate analysis for user convenience. Additionally, GERONIMO supplements homologous sequences with genomic regions to analyze promoter motifs or gene collinearity, enhancing the validation of results. GERONIMO, built using Snakemake, has undergone extensive testing on hundreds of genomes, establishing itself as a valuable tool in the identification of ncRNA homologs across diverse taxonomic groups. Consequently, GERONIMO facilitates the investigation of the evolutionary patterns of functionally significant ncRNA players, whose understanding has previously been limited to individual organisms and close relatives.

Centaurea Subsect. Phalolepis (Compositae, Cardueae): A Case Study of Mountain-Driven Allopatric Speciation in the Mediterranean Peninsulas.

Centaurea subsection Phalolepis has been thoroughly analyzed in previous studies using microsatellites in four centers of speciation: Anatolia, Greece, the Italian Peninsula and the Iberian Peninsula. Evidence suggests a correlation between taxon diversity and mountains. This group constituted a good case study for examining the mountain-geobiodiversity hypothesis (MGH), which explains the possible reasons for the many radiations occurring in mountains across the world. We combined all the datasets and carried out analyses of their genetic structure to confirm the species of subsect. Phalolepis are grouped according to a geographic pattern. We then checked whether climatic fluctuations favored the "species pump" hypothesis in the mountains by using the Climatic Stability Index (CSI). Finally, the relief of the terrain was tested against the rate of allopatric speciation by region by means of Terrain Ruggedness Index and environmental gradients through our new Climate Niche Breadth Index. Our results supported the MGH hypothesis and confirmed that the main triggers, namely altitudinal zonation, climatic oscillations and rugged terrain, must be present for the development of a radiation.

Integrative approach resolves the taxonomy of Eulaema cingulata (Hymenoptera, Apidae), an important pollinator in the Neotropics

Species delimitation is a rich scientific field that often uses different sources of data to identify independently evolving lineages that might be recognized as species. Here, we use an integrative approach based on morphometrics, COI-barcoding, and phylogenomics using ultraconserved elements (UCEs) to investigate whether the orchid bee species Eulaema cingulata (Fabricius, 1804) and E. pseudocingulata Oliveira, 2006 represent a single variable taxon or two different species. We analyzed 126 specimens across the geographical range of these nominal species to test species hypotheses using the general lineage concept. We found substantial overlap in wing and head morphometrics, and both taxa form one phylogenetic lineage based on COI mitochondrial and UCE data. Our results support the recognition of both forms as members of the same evolutionary unit and E. pseudocingulata is herein recognized as a junior synonym of E. cingulata.

Insights into the evolutionary history and taxonomic status of Sinopteris (Pteridaceae)

As an endemic Chinese genus, Sinopteris C. Chr. & Ching was once considered an early diverged taxon of cheilanthoid ferns, and its taxonomic status has long been controversial. In this study, eight datasets spanning the complete chloroplast genomes and three nuclear genes were used to reconstruct the phylogeny of Sinopteris and its relatives. In addition, combining morphological analyses, divergence time estimation, and ancestral trait reconstruction, the origin and evolutionary history of Sinopteris were comprehensively discussed. Based on the complete chloroplast genome dataset, our analyses yielded a phylogram with all clades strongly supported (ML-BS = 100, BI-PP = 1.0), and the topology was almost identical to that based on the concatenated sequences of nrDNA, CRY2, and IBR3. Two species of Sinopteris were united and sister to Aleuritopteris niphobola (C. Chr.) Ching. They constituted a stable monophyletic group embedded in Aleuritopteris Fée. This was also consistent with the results of morphological analyses. Divergence time estimation indicated that the clade of Aleuritopteris and Sinopteris originated in the early Miocene (ca. 16.80 Ma) and experienced two rapid diversifications, which could coincide with environmental heterogeneity caused by the progressive uplift of the Himalayas and the intense uplift of the Hengduan Mountains. Sinopteris originated in the late Miocene (ca. 6.96 Ma), accompanied by the sharp intensifications of Asian Monsoon, and began to diversify at 2.34 Ma, following the intense uplift of the Hengduan Mountains. Ancestral character reconstruction showed that monangial sori and subsessile sporangia were clearly late derived states rather than early diverged states. Both the molecular phylogenetic and morphological analyses support the inclusion of Sinopteris in Aleuritopteris.

Sea lamprey nests promote the diversity of benthic macroinvertebrate assemblages.

The habitat heterogeneity hypothesis states that increased habitat heterogeneity promotes species diversity through increased availability of ecological niches. We aimed at describing the local-scale (i.e. nest and adjacent substrate) effects of nests of the sea lamprey (Petromyzon marinus L.) as ecosystem engineer on macroinvertebrate assemblages. We hypothesized that increased streambed physical heterogeneity caused by sea lamprey spawning would modify invertebrate assemblages and specific biologic traits and promote reach-scale diversity. We sampled thirty lamprey nests of the Nive River, a river of the south western France with a length of 79.3 km and tributary of the Adour River, in three zones: the unmodified riverbed (upstream) and zones corresponding to the nest: the area excavated (pit) and the downstream accumulation of pebbles and cobbles (mound). The increased habitat heterogeneity created by lamprey was accompanied by biological heterogeneity with a reduced density of invertebrates (3777 ± 1332 individuals per m2 in upstream, 2649 ± 1386 individuals per m2 in pit and 3833 ± 1052 individuals per m2 in mound) and number of taxa (23.5 ± 3.9 taxa for upstream, 18.6 ± 3.9 taxa in pit and 21.2 ± 4.5 taxa for mound) in the pit compared to other zones. However the overall taxa diversity in nest increased with 82 ± 14 taxa compared to the 69 ± 8 taxa estimated in upstream zone. Diversity indices were consistent with the previous results indicating a loss of α diversity in pit but a higher β diversity between a pit and a mound than between two upstream zones, especially considering Morisita index accounting for taxa abundance. Trait analysis showed high functional diversity within zones with a reduced proportion of collectors, scrapers, shredders, litter/mud preference and small invertebrates in mound, while the proportion of "slabs, blocks, stones and pebbles" preference and largest invertebrates increased. Pit presented the opposite trend, while upstream had globally intermediate trait proportions. Our results highlight important effects on species and functional diversity due to habitat heterogeneity created by a nest-building species, what can ultimately influence food webs and nutrient processes in river ecosystems.

Landscape effects on pollinator abundance differ among taxonomic groups

AbstractUnderstanding how landscape composition affects pollinator abundance is crucial for conserving the sustainability of the symbiotic relationship between plants and pollinators. However, field evidence on the effect of landscape composition and spatial scales on the abundance of each pollinator group is biased toward bee pollinators, and non‐bee pollinators tend to be excluded. This study aims to evaluate the effect of landscape composition at various spatial scales on diverse taxonomic groups of pollinators, including non‐bee pollinators. We selected 22 grasslands with varying landscape compositions in Shiroi City, Chiba Prefecture, Japan. We recorded the abundance of pollinators and floral resource availability at these sites. The effects of landscape composition within a 100–1000 m radius and the floral resource availability were analyzed using Bayesian generalized linear mixed models to determine whether these factors affected the abundance of each pollinator group. As a result, the difference in important factors among the pollinator groups was detected; Scoliidae, Lycaenidae, Stomorhina obsoleta, and Sphaerophoria were influenced by the landscape composition, whereas Bombus diversus and Hesperiidae were not. Scoliidae was affected by the proportion of agri‐field and forest areas within a 500–1000 m radius. St. obsoleta and Sphaerophoria showed different response patterns to the proportion of urban land within a 100 m radius. B. diversus and Hesperiidae were influenced by floral resource availability. Our study suggests that considering the spatial scales of landscape composition on the target species is essential to plan effective conservation measures.

The ephemeral pans of Gras-Holpan: Mokala National Park, Northern Cape, South Africa

Ephemeral pans are transient natural habitats with harsh conditions found in semi-arid regions. These pans endure high evaporation rates, extreme temperatures and an overflow of water. Pans are characterised by dry land becoming submerged in water temporarily (flood-like) followed by a prolonged period absent of water (drought-like). Ephemeral pans are unique habitats that are essentially transient habitats from a freshwater system to increased salinity and eventually a dry landscape. Biodiversity associated with these pans must adapt to the transient environmental conditions. Unique adaptations of the biota for these habitats allow them to withstand extreme conditions. The objective of this study was to (1) identify changes in the water quality over time in the pans, to (2) identify succession of macro-invertebrates and (3) identify the water quality parameters of pans as drivers of macro-invertebrate assemblages. A total of five pans were measured in the Northern Cape province of South Africa located on the Savanna and Nama-Karoo biomes within a 4500 ha area. The measurements taken included water quality variables (pH, salinity, total dissolved solids [TDS]), taxon diversity and richness of macro-invertebrates and aquatic birdlife. Evaporation rate between the pans varied with time. There was a difference in the macro-invertebrate taxon richness between the pans. Macro-invertebrate taxon succession was observed over time and some macro-invertebrates showed confinement to pans of a particular biome. It was found that pH was significantly the most contributing factor to the taxon richness and diversity of the macro-invertebrates recorded, while the salinity and TDS increased with time as water evaporated.Conservation implications: The shrimps (fairy, clam and tadpole) were unique to the Nama-Karoo pans. It was found that pH (p 0.05) was the most contributing factor to the taxon richness and diversity of the macro-invertebrates recorded, and salinity and TDS increased with time as water evaporated.

Bat diversity is driven by elevation and distance to the nearest watercourse in aterra firmeforest in the northeastern Brazilian Amazon

AbstractVariations in environmental conditions along gradients play an important role in species distribution through environmental filtering of morphological and physiological traits; however, their effects on bat diversity remain poorly understood. Here, we investigate the effect of the distance to the nearest watercourse, terrain elevation, vegetation clutter, basal area and canopy height on taxonomic, functional and phylogenetic diversity and on the predominance of some functional traits (body mass, wing morphology and trophic level) of bat assemblages (phyllostomid and mormoopid bats) in aterra firmeforest, in the northeastern Brazilian Amazon. We captured bats using mist nets in 15 permanent plots over a 25 km2area of continuous forest. We captured 279 individuals belonging to 28 species with a total of 77.760 m2.h of sampling effort. Our results showed that bat richness increases as a function of distance to the nearest watercourse and that the assemblage also changes, with more diverse taxonomic and functional groups in areas further from the watercourse. Furthermore, elevation positively affects species richness, and the basal area of the forest positively influences the average body mass of bats. Taken together, our results demonstrate that subtle variations in the environmental conditions along a local scale gradient impact on the main dimensions of bat diversity in primary forests.

Deep Diversity: Extensive Variation in the Components of Complex Visual Systems across Animals

Understanding the molecular underpinnings of the evolution of complex (multi-part) systems is a fundamental topic in biology. One unanswered question is to what the extent do similar or different genes and regulatory interactions underlie similar complex systems across species? Animal eyes and phototransduction (light detection) are outstanding systems to investigate this question because some of the genetics underlying these traits are well characterized in model organisms. However, comparative studies using non-model organisms are also necessary to understand the diversity and evolution of these traits. Here, we compare the characteristics of photoreceptor cells, opsins, and phototransduction cascades in diverse taxa, with a particular focus on cnidarians. In contrast to the common theme of deep homology, whereby similar traits develop mainly using homologous genes, comparisons of visual systems, especially in non-model organisms, are beginning to highlight a "deep diversity" of underlying components, illustrating how variation can underlie similar complex systems across taxa. Although using candidate genes from model organisms across diversity was a good starting point to understand the evolution of complex systems, unbiased genome-wide comparisons and subsequent functional validation will be necessary to uncover unique genes that comprise the complex systems of non-model groups to better understand biodiversity and its evolution.