Richness Estimates Research Articles

Mammal inventory using camera traps in the Central Forest State Nature Reserve (West of European Russia)

A mammal species inventory by estimating their richness is the first and necessary task of any mammal monitoring programme. This paper presents estimates of species richness of mammals (mostly medium and large body-sized) in the Central Forest State Nature Reserve (European Russia). Based on data collected in 2023 from 55 camera trap locations (19 676 camera days), 59 035 images of wild mammals were obtained. A total of 18 species were recorded. Of these, ten species were representatives of the Carnivora, four – Artiodactyla, two – Rodentia, one – Erinaceomorpha, and one – Lagomorpha. This amounted to 84% of all potentially camera-trapped mammals observed in the Central Forest State Nature Reserve. The relative abundance index (RAI) and naïve occupancy (ψnaive) were calculated for all species. The most common and frequently recorded were Meles meles (RAI = 4.95; ψnaive = 0.96), followed by Ursus arctos (RAI = 4.39; ψnaive = 1) and Lepus timidus (RAI = 4.08; ψnaive = 1), while the most rarely recorded species were Castor fiber (RAI = 0.01; ψnaive = 0.02), Erinaceus europaeus (RAI = 0.02; ψnaive = 0.04), and Lutra lutra (RAI = 0.03; ψnaive = 0.07). Large and medium-sized carnivorous and omnivorous mammal communities were the fastest and most completely captured. According to the constructed single-season multispecies occupancy model with Markov chains Monte Carlo, camera traps failed to record 4–5 more possible species. These species are likely to be Mustela lutreola, M. erminea, and Mustela nivalis, as well as two invasive species, Cervus nippon and Capreolus pygargus. All the captured species were recorded in total in a short period of time, namely from the end of March to the beginning of May during 1869 camera-days. Two of them (Castor fiber and Erinaceus europaeus) were recorded exclusively at this time, and they were not captured further until the end of the year. This emphasises the importance of conducting mammal inventory, with inclusion of the spring season.

Sampling origins and directions affect the minimum sampling area in forest plots

AbstractQuestionsThe minimum sampling area (minimum area) is the smallest space that reflects species composition and characteristics of a plant community. The quantitative concept of minimum area is often estimated using species–area relationships (SARs) and has become the classical foundation for managing protected areas. However, sampling designs to determine the minimum area in different forest types have not been systematically evaluated.LocationChina.MethodsWe used tree census data from three forest dynamic plots, each with a size of 25–60 ha, in different climatic zones in China to determine the minimum areas of woody plants and to analyze the effects of species richness and topographic heterogeneity on the minimum areas by changing sampling origin and direction.ResultsWe found that mainly sampling design affects the estimation of woody plant species richness and required minimum area in different forest types. The estimated size of the minimum areas required was several hectares and varied significantly with sampling origin and direction, and showed a difference of approximately 1.5–2 times in the forest plots. Topographic heterogeneity significantly affected the minimum area through changes in species composition.ConclusionsSampling origin and direction should be considered when using SARs to estimate the minimum area and species diversity in communities. Such a comprehensive approach of sampling can contribute to a better understanding of vegetation characteristics and the minimum area required for a conservation census in heterogeneous environments.

Distribution of Subgingival Bacteria in Chronic Periodontitis Patients Correlated with IgA Nephropathy.

Several studies indicated that chronic periodontitis (CP) and its subgingival bacteria correlated with IgA nephropathy (IgAN). Previous research has shown that prevalence of IgAN in chronic periodontitis patients is significantly higher than that in non CP patients in Xinjiang especially in ethnic Uyghur. The aim of this study is to investigate the distribution of plaque bacterial microbes in CP and IgAN patients and to find correlation between CP and IgAN. All of the subgingival plaque samples including 7 healthy controls (N group), 8 CP patients, 14 IgAN patients, and 14 CP with IgAN patients were obtained from ethnic Uyghur people. To investigate the distribution of plaque microbe in Uyghur CP and IgAN patients, the 16s rRNA sequencing and comparative analysis of subgingival bacteria were performed. There were no statistically differences in the community richness estimator (Chao) and the diversity estimator (Shannon index) among four groups. The abundance of Burkholderiales (order), Ottowia (genus) in the plaque microbes were significantly higher in CP with IgAN patients than CP patients. The abundance of Eubacterium (genus) was significantly higher in CP with IgAN patients than IgAN patients. The abundance of Veillonella (genus) was significantly higher while Streptococcus (genus), Tannerella (genus) were significantly lower in CP patients than healthy volunteers. The composition and abundance of subgingival plaque microbes in Uyghur CP and IgAN patients were significantly different at several levels. Which suggested that abundance of subgingival bacteria is correlated to CP and IgAN.

Revealing floristic and structural variation in regenerating areas in the Cerrado-Caatinga transition: an analysis across seres

Abstract In the savanna-seasonally dry tropical forest ecotone in Northeastern Brazil, we studied variations in flora and structure within old growth and two sites in secondary succession (10 and 25 years). We sampled 2,127 trees and shrubs with a diameter at ground level of 3 cm or more, excluding cacti, palm trees, and vines. Old growth contained 478 plants from 29 species, the 25-year site had 819 plants from 27 species, and the 10-year site had 829 plants from 25 species, totaling 38 species across the sites. Regarding the regenerating stratum, we found 2,776 individuals, with the largest and smallest number of individuals for 10 and 25 years regeneration, respectively. Rarefaction and Jacknife richness showed greater tree richness in old growth, whereas 10 and 25 years regeneration presented similar richness estimates; furthermore, the highest richness in the regenerating stratum was observed in 10 years and the lowest in old growth. Our results reveal that changes in composition are caused by species replacement, demonstrating that even in areas deforested for traditional agriculture, turnover causes significant changes in composition and results in the requirement of a long time for reestablishment, similar to the old growth.

Floristic diversity and edaphic filters in an urban forest under Cerrado domain, in Cuiabá, Central Western Brazil.

We aimed to characterize the adult and regenerating tree components and their relationships with soil characteristics of a native vegetation remnant in Cuiabá, Mato Grosso, Brazil. The area of the fragment is stratified into "dry area" (lithic neosoil) and "damp area" (gleisoil). We conducted a forest inventory with a random distribution of 25 parcels. We analyzed the physical and chemical components of the soil. We evaluated the vegetation's horizontal structure, diversity, and sample sufficiency using the Bootstrap richness estimator. We classified the species according to dispersal syndrome and ecological group. Overall, we found 93 species in the adult layer and 70 species in the regenerating layer. The similarity dendrograms based on the two evaluated indices demonstrated the existence of the two initially stratified environments in both strata. The IndVal (%) indicated that the set of indicator species differed between the strata. Thereby, the fragment is in an intermediate stage of successional progression. PCA showed that plots in the wet area had higher pH values and Ca, Zn, and Fe levels, while plots in the dry area did not clearly distinguish, varying in terms of K, B, and organic matter content. In CCA, a set of species that occurred exclusively in the damp area showed a strong relationship with the analyzed variables. The area is a diverse ecosystem that efficiently provides ecosystem services to society and should be the subject of long-term conservation and research.

Association of Root Biofilm Bacteriome with Root Caries Lesion Severity and Activity

Introduction: This research aimed to assess the association of root biofilm bacteriome with root caries lesion severity and activity in institutionalised Colombian elderlies and was conducted to gather data on the root caries bacteriome in this population. Methods: A bacteriome evaluation of biofilm samples from sound and carious root surfaces was performed. Root caries was categorised (ICDAS Root criteria) based on severity (sound surfaces, initial: non-cavitated, moderate/extensive combined: cavitated) and activity status (active and inactive). DNA was extracted and the V4 region of the 16S rRNA gene was sequenced; afterwards the classification of features was conducted employing amplicon sequence variants and taxonomic assignment via the Human Oral Microbiome Database (HOMD). Bacterial richness, diversity (Simpson’s and Shannon’s indices), and relative abundance estimation were assessed and compared based on root caries severity and activity status (including Sound surfaces). Results: A total of 130 biofilm samples were examined: sound (n = 45) and with root caries lesions (n = 85; by severity: initial: n = 41; moderate/extensive: n = 44; by activity: active: n = 60; inactive: n = 25). Species richness was significantly lower in biofilms from moderate/extensive and active groups compared to sound sites. There was a higher relative abundance of species like Lechtotricia wadei, Capnocytophaga granulosa, Cardiobacterium valvarum, Porphyromonas pasteri – in sound sites; Dialister invisus, Streptococcus mutans, Pseudoramibacter alactolyticus and Bacteroidetes (G-5) bacterium 511 – in moderate/extensive lesions, and Fusobacterium nucleatum subsp. animalis, Prevotella denticola, Lactobacillus fermentum, Saccharibacteria (TM7) (G-5)bacterium HMT 356 – in active lesions. Conclusion: Root caries bacteriome exhibited differences in species proportions between the compared groups. Specifically, cavitated caries lesions and active caries lesions showed higher relative abundance of acidogenic bacteria.

Changes in the bird communities of Nothofagus forests in a long‐term plot in Tierra del Fuego

AbstractLong‐term studies have proven to be important to characterize animal communities and analyse the ecological responses to climate and environmental changes. These studies are necessary to determine the natural community variability (e.g., richness and density) to develop better conservation strategies to face climate changes. Here, we analysed the natural changes in the structure and functional traits of bird communities over 13 consecutive years (2010–2022) and determined the number of years of sampling needed to obtain a good estimation of the community structure variables in deciduous high latitude Nothofagus forests. Using point counts, we studied closed (80% of canopy cover) and open (40% of canopy cover) forests inside the Tierra del Fuego National Park. Species richness, density, biomass, and functional traits (migratory status, trophic groups, nest type, and feeding strata) were analysed using generalized linear models with forest type (closed and open) and year (2010–2022) as the main factors, while the standard error (SE) of sampling obtained from one to 12 sampling years was compared. Richness was significantly higher in open forests (p < 0.01), while density and biomass were higher in closed forests. Additionally, density and biomass significantly varied among years in both forest types (e.g., lower density in 2013, 2014 and 2015, and higher in 2019). The density of birds for some functional traits also varied among years and forest types (e.g., higher values of cavity nesters in closed forests during 2019). Five to six years of sampling were needed to have an acceptable estimation of richness (20% SE), between 10 and 12 years for density, and >12 years for biomass. This study highlights the importance of long‐term studies to visualize natural variations in undisturbed habitats along time.

Factors that interfere with the estimation of bat richness in Atlantic Forest, southeastern Brazil

Capture success of bats can be affected not only by local bat density, but also by several methodological aspects. Many factors interfere with the sampling completeness and capture success of bats. Considering the variety of sampling methods used for investigating, the objective of the present study is to analyze different factors that interfere with sampling completeness and species richness estimates of bats. To carry out the present study, we used data from the State of Rio de Janeiro from inventories carried out from 1989 to 2013 by the Laboratory of Bat Diversity and data from the literature until 2023. We analyzed the following parameters: number of sampling nights, period of nocturnal sampling, number of sites where the mist nets were opened, sampling in diurnal roosts, and moon phase. We observed that the localities with more than 30 species recorded had huge sampling efforts. For studies based on a small capture effort, the active search for roosts during the day increases the probability of recording species found mainly in high sampling effort studies. The most complete inventories are those with a sampling effort of at least 24 nights, including sampling in different habitats, such as trails, water bodies, and close to fruiting plants, as well those including search for day roosts and with fieldwork not restricted to a specific moon phase. Mist nets should be set up not only on trails and close to fruiting trees, but also over water bodies to increase the probability of recording insectivorous species.

A meta‐analysis examining how fish biodiversity varies with marine protected area size and age

AbstractMarine protected areas (MPAs) are a well‐established conservation practice worldwide, but their effectiveness in protecting or replenishing fish biodiversity remains uneven. Understanding the patterns of this heterogeneity is central to general guidelines for MPA design and can ultimately provide guidance on how to maximize MPA potential. Here, we examine associations between the degree of protection, duration of protection, and protected area size, with fish biodiversity inside of protected areas relative to that of sites nearby, but outside of protected areas. We quantitatively synthesize 116 published estimates of species richness from 72 MPAs and 38 estimates of Shannon entropy from 21 MPAs. We show that species richness is on average 18% (95% CIs: 10%–29%) higher in protected areas than in areas open to fishing; on average, Shannon entropy is 13% (95% CIs: −2% to 31%) higher within protected areas relative to outside. We find no relationship between the degree and duration of protection with the ratio of species richness inside versus outside of protected areas; both fully and partially protected areas contribute to the accumulation of species inside of protected areas, and protected areas of all ages contribute similarly on average to biodiversity conservation. In contrast to our expectations, increasing protected area size was associated with a decreased ratio of species richness sampled at sites inside versus outside of the protected area, possibly due, for example, to insufficient enforcement and/or low compliance. Finally, we discuss why meta‐analyses such as ours that summarize effect sizes of local scale biodiversity responses, that is, those at a single site, can only give a partial answer to the question of whether larger protected areas harbor more species than comparable unprotected areas.

Species richness pattern of aquatic vascular macrophytes along elevation gradients in Nepal Himalayas

Abstract. Siwakoti EA, Nepali B, Mandal TN, Baniya CB. 2023. Species richness pattern of aquatic vascular macrophytes along elevation gradients in Nepal Himalayas. Biodiversitas 24: 5179-5190. Aquatic vascular macrophytes constitute an important component of aquatic ecosystems. This study aims to determine the species richness pattern of aquatic vascular macrophytes along elevation gradients (100-4900 m asl) in the Nepal Himalayas. We used available published literature on elevational ranges of aquatic vascular macrophytes in Nepal to interpolate the species elevational ranges, thereby providing species richness estimates for 100 m elevational bands. A total of 113 species of aquatic vascular macrophytes belonging to 66 genera under 35 families were recorded from Nepal. Among these macrophytes, dicots were represented by 21 families, monocots with 10 families and pteridophytes with 4 families. Regarding the geographical divisions, the total number of aquatic vascular macrophytes recorded was 76 from the east, 90 from the central and 67 from the west, conclusively central Nepal showed the maximum number of macrophytes. The highest species richness was contributed by Hydrocharitaceae followed by Potamogetonaceae, Plantaginaceae, Lentibulariaceae and Nymphaeaceae. So far, the functional types of macrophytes are concerned, free-floating species were 15, submerged species were 36, floating-leaved species were 18 and emergent species were 44 along elevation gradients in the three geographical divisions in Nepal. The Generalized Linear Model (GLM) was applied to find out the relation between the species richness of aquatic vascular macrophytes with elevation. It showed a statistically significant monotonic declining pattern with increasing elevation. The occurrence of this model was further verified by aquatic vascular macrophyte richness at every 200 m elevation which converged with the general pattern. The study conducted along one of the world’s longest bioclimatic elevational gradients led to support the monotonic declining pattern of aquatic vascular macrophytes richness indicating the difference in richness pattern among aquatic and terrestrial ecosystems. It also emphasizes the importance of conserving aquatic ecosystems with their vegetation.

The Influence of Grazing Systems on Bird Species Richness and Density in the Nebraska Sandhills

Grazing is the de facto method of habitat management used in much of the Nebraska Sandhills. Ranchers use a variety of grazing systems, and our goal was to evaluate the effects of systems on grassland birds. We estimated the species richness and density of grassland birds for three grazing systems used on private ranches: long, medium, and short duration grazing systems. We observed sixty species, and the grazing system with pastures utilizing long duration grazing periods had the highest estimates of species richness as well as the most heterogeneous habitat structure. Differences in species richness among systems were most pronounced in years of limited precipitation. Together, grasshopper sparrows (Ammodramus savannarum), western meadowlarks (Sturnella neglecta), and brown-headed cowbirds (Molothrus ater) accounted for 72% of our observations. We used a model comparison approach to determine the effects of habitat on the densities of six species. Densities of grasshopper sparrows and mourning doves showed effects of the grazing system. More species had higher densities in short duration, rotational systems than other grazing systems. However, species of grassland birds showed responses to a variety of cover types and habitat structures depending on life history needs. Regardless of the grazing system used, managers can use grazing and other tools such as prescribed burning to maintain habitat heterogeneity to support diverse bird communities.

Effects of forest management on private lands in West Virginia on Cerulean Warblers (Setophaga cerulea) and the avian community

The USDA Natural Resources Conservation Service (NRCS) supports private lands conservation projects across the United States to benefit imperiled focal wildlife species using conservation practices to restore habitat. The Cerulean Warbler Appalachian Forestland Enhancement Project (CWAFEP) was initiated in 2015 to help stabilize or reverse Cerulean Warbler population declines by using forest management to create or enhance breeding habitat on private lands in Appalachian focal areas. We evaluated Cerulean Warbler occupancy on CWAFEP sites treated using NRCS conservation practices to inform adaptive management strategies. We also assessed associated forest focal species’ occupancy and species richness of avian guilds to evaluate the effects of conservation practice implementation on the avian community. We conducted point count surveys at 194 locations on 21 private properties enrolled in the CWAFEP in West Virginia during May – July 2019 and 2020. We compared occupancy among four treatments: reference, pre-treatment, 1-year post-treatment, and 2 – 4 years post-treatment sites. To examine how vegetation structure changes among treatments affected occupancy, we also collected and included vegetation variables. Cerulean Warbler occupancy estimates were not different among treatments, suggesting that post-treatment study sites surveyed did not achieve their goal of increasing Cerulean Warbler occupancy. Cerulean Warbler occupancy decreased by 91 % as elevation increased from 200 to 800 m and increased by 397 % as sapling cover increased from 0 to 100 %. Occupancy for three forest focal species (Blue-gray Gnatcatcher, Eastern Wood-pewee, and Scarlet Tanager) and species richness of four avian guilds also were not different among treatments. Thus, Cerulean Warbler occupancy and selected avian community demographics were not related to recent conservation practice implementation in the short-term (1 – 4 years post-treatment), but there are opportunities to improve NRCS conservation practice implementation for more effective Cerulean Warbler conservation. We suspect that the lack of differences in occupancy and species richness estimates was due to site selection related to ecoregion, small treatment areas, and challenges associated with private lands conservation efforts resulting in insufficient reduction in basal area. If NRCS conservation practices implemented through CWAFEP are going to help reverse Cerulean Warbler population declines, CWAFEP sites need to achieve the recommended basal area range of ∼ 9.2 – 20.7 m 2/ha (40 – 90 ft2/ac) during contract implementation. Our conclusions are critical to updating our knowledge for Cerulean Warbler best management practices and informing future regional conservation implementation.

Validating a multi-locus metabarcoding approach for characterizing mixed-pollen samples

BackgroundThe mutualistic interaction between entomophilous plants and pollinators is fundamental to the structure of most terrestrial ecosystems. The sensitive nature of this relationship has been disrupted by anthropogenic modifications to natural landscapes, warranting development of new methods for exploring this trophic interaction. Characterizing the composition of pollen collected by pollinators, e.g. Apis mellifera, is a common means of exploring this relationship, but traditional methods of microscopic pollen assessment are laborious and limited in their scope. The development of pollen metabarcoding as a method of rapidly characterizing the abundance and diversity of pollen within mixed samples presents a new frontier for this type of work, but metabarcoding may have limitations, and validation is warranted before any suite of primers can be confidently used in a research program. We set out to evaluate the utility of an integrative approach, using a set of established primers (ITS2 and rbcL) versus melissopalynological analysis for characterizing 27 mixed-pollen samples from agricultural sites across Canada.ResultsBoth individual markers performed well relative to melissopalynology at the family level with decreases in the strength of correlation and linear model fits at the genus level. Integrating data from both markers together via a multi-locus approach provided the best rank-based correlation between metagenetic and melissopalynological data at both the genus (ρ = 0.659; p < 0.001) and family level (ρ = 0.830; p < 0.001). Species accumulation curves indicated that, after controlling for sampling effort, melissopalynological characterization provides similar or higher species richness estimates than either marker. The higher number of plant species discovered via the metabarcoding approach simply reflects the vastly greater sampling effort in comparison to melissopalynology.ConclusionsPollen metabarcoding performed well at characterizing the composition of mixed pollen samples relative to a traditional melissopalynological approach. Limitations to the quantitative application of this method can be addressed by adopting a multi-locus approach that integrates information from multiple markers.

Discovering the fish fauna of a lagoon from the southeast of the Yucatan Peninsula, Mexico, using DNA barcodes

Background Aquatic ecosystems in the tropics are typically environments with a high species richness of fishes. These systems are also among the most vulnerable in the world, threatening the overall biodiversity of tropical regions. As a first step, it is important to enumerate the species in any ecosystem to promote its conservation. This study aims to inventory the ichthyofauna in the Chile Verde Lagoon, Quintana Roo, on the Yucatan Peninsula, a system fortunately well protected in Mexico, based on faunal surveys backed up with mtDNA barcodes. Methods We collected larvae, juveniles, and adults of fishes in the lagoon with a variety of sampling gear targeting various life stages. Species were identified using both morphology and DNA barcodes. The abundance of species and ichthyoplankton biomass (wet weight, suction technique) were calculated from 43 samples. Results We collected 197 adult and juvenile fishes and 3,722 larvae, of which 306 specimens were DNA-sequenced with a success rate of 96.7%. We identified 13 families, 24 genera, and 27 species in our inventory. The species number was estimated to comprise 75% of the potential total richness using the Chao 1 richness estimator. Clupeids and gobiids accounted for 87.9% of the total abundance of fishes, and, together with cyprinodontids, also accounted for the highest ichthyoplankton biomass. Conclusion Adult and juvenile fishes were identified by morphology and meristic values, however larvae required DNA barcoding to identify species. The high biomass and abundance of larvae of clupeids, gobiids and cyprinodontids suggests that the Chile Verde Lagoon may be important for reproduction of these species in the region. Microgobius microlepis, a marine goby species, is reported for the first time in an inland oligohaline system. This study provides a basis for future environmental assessment and biomonitoring of the Chile Verde Lagoon in the Yucatan Peninsula of Mexico.

Implications of dietary soybean meal replacement with corn gluten meal on growth performance, antioxidant activities, hepatopancreatic histopathology, and intestinal flora of juvenile Pacific shrimp (Litopenaeus vannamei)

This study aimed to investigate the potential of replacing soybean meal (SBM) with corn gluten meal (CGM) in the diet of Pacific white shrimp (Litopaeneaus vannamei). The study examined the effects of a dietary soybean meal replacement on growth, biochemical indices, antioxidant activities, histology, and intestinal flora. A total of 840 juvenile Pacific shrimp were fed seven diets containing different levels of CGM, ranging from diet 1 (diet1) 0% (control), diet2 (3%), diet3 (7%), diet4 (9%), diet5 (11.8%), diet6 (12.7%), and diet 7 (14.4%). The experiment was conducted over 56 days, with three replicate of each group (initial mean weight = 0.13 0.00 g). The results showed that dietary CGM significantly increased final body weight, average weight gain, and specific growth rate. However, the inclusion of dietary CGM decreased with higher levels. The feed conversion ratio of diets 2 and 3 was considerably lower than that of the control group. The activities of alkaline phosphatase and acid phosphatase increased significantly with the feeding of CGM, while the levels of alanine aminotransferase and aspartate aminotransferase decreased significantly. The histology of the hepatopancreas showed an evident epithelial tubule (E, B, R, and F), and the number of intact epithelial cells increased considerably with the increasing inclusion of CGM (P < 0.05). The intestinal flora in the shrimp intestine responded favorably to the replacement of SBM with CGM in the dietary CGM treatment groups, including a number of beneficial bacteria such as Bacteroidetes and Firmicutes. Moreover, with rising CGM levels, diversity indices and richness estimates rose. The regression model with a broken line was found to describing the relationship between the growth rate and the optimal level of CGM required. The results showed that a CGM dose of 3.31% was the most effective for achieving optimal growth performance in juvenile L. vannamei.

Observed and estimated taxonomic diversity of different groups of aquatic organisms in the pristine rivers in the Biebrza National Park

The study focuses on the pristine rivers of the Biebrza National Park (BNP), an extensive area of wetlands, which holds significant biodiversity importance on a European scale. The aim of this work was to identify the taxonomic resources of the river network of this area and to compare the biodiversity of various aquatic organisms, and moreover, evaluate the field sampling effort required to identify the whole pool of taxa inhabiting the survey area. Fieldwork was carried out in 2021 at 25 survey sites, where the taxonomic compositions of five groups of organisms were identified: benthic diatoms, phytoplankton, macrophytes, benthic macroinvertebrates, and ichthyofauna and identified taxa have been presented in the appendix. The biodiversity indices of these groups were calculated, i.e. the species richness, and the Shannon and Simpson indices. The entire predicted biodiversity of these groups of organisms was also estimated. The Chao2 asymptotic taxonomic richness estimator for incidence data was used to calculate the additional number of survey sites that would be required to discover 80%, 90% and 100% of the anticipated taxonomic richness in each of the five groups of organisms. With the information on the species inhabiting the Biebrza Valley that this survey yielded, the biodiversity at a single site (alpha diversity) and within the entire area surveyed (gamma diversity) was estimated. The phytoplankton (475 taxa) and the benthic macroinvertebrates (308) showed the greatest diversity in taxonomic richness. In addition, there were 151 species in the benthic diatom group, 72 macrophyte taxa, and 24 fish species. The analysis showed, moreover, that if the fieldwork were continued, another 110 phytoplankton and 104 benthic macroinvertebrates taxa would be recorded for BNP, along with 40 further species of benthic diatoms, 9 more macrophyte species, and 2 more fish species. Alpha diversity was found to be high but gamma diversity was relatively low due to the homogeneous nature of the rivers surveyed (low beta diversity), effective conservation measures, and minimal human disturbances.

Early eukaryotic microfossils of the late Palaeoproterozoic Limbunya Group, Birrindudu Basin, northern Australia

AbstractFine‐grained, siliciclastic units of the &gt;1642 ± 3.9 Ma late Palaeoproterozoic Limbunya Group, Birrindudu Basin host rich, well‐preserved organic‐walled microfossil assemblages that include members of total‐group eukaryotes. These assemblages include taxa characteristic of this interval such as Tappania plana and Satka favosa, as well as less common taxa such as Gigantosphaeridium fibratum, Gigantosphaeridium floccosum, Kamolineata elongata (= Valeria elongata; new combination), and four new species. The new taxa include Limbunyasphaera operculata gen et sp. nov., the oldest known operculate taxon; the large septate filaments of Siphonoseptum bombycinum gen. et sp. nov.; the platy tubular form Birrindudutuba brigandinia gen. et sp. nov.; and Filinexum torsivum gen. et sp. nov., which bears a spirally twisted wall constructed of bound fibres. Our data show that eukaryotic fossils are particularly abundant in marginal marine environments such as tidal flats and back‐barrier lagoonal settings. This is exemplified by the Blue Hole Formation, which features an especially diverse and complex assemblage. We also present a new within‐formation eukaryotic species richness estimate for the Palaeoproterozoic to Tonian. This estimate indicates that the oldest eukaryote‐bearing units already show species richness levels similar to those of the much younger and more heavily sampled Tonian period. Additionally, these oldest eukaryotic assemblages show significant morphological disparity, particularly in vesicle construction. These high levels of eukaryotic species richness and morphological disparity suggest that although late Palaeoproterozoic units preserve our oldest record of eukaryotes, the eukaryotic clade has a much deeper history.

Species diversity and spatial distribution of mosquitoes (Diptera: Culicidae) from La Isla Amazon Park, Napo Province, Ecuador

Introduction: Vector-borne diseases are prevalent in the Amazon and Coastal regions of Ecuador. However, there is a scarcity of mosquito ecology studies in these areas. The most recent list of species reported for the country comprises 8 tribes, 22 genera, and 200 species. Objectives: To document the Culicidae species found in La Isla Amazon Park, Napo, Ecuador, including those with epidemiological significance; and to analyze their composition, abundance, and diversity, focusing on larval habitats during the dry and rainy periods. Methods: We evaluated different larval habitats, considering collection duration as the primary criterion. We used CDC and Shannon traps to collect adult mosquitoes during both rainy and dry periods. To assess sampling effort, we used accumulation curves and non-parametric estimators of species richness, while we employed Hill numbers to determine diversity. Additionally, we used the Berger-Parker and Pielou indices to evaluate species dominance and evenness. We conducted cluster analysis and ANOSIM tests to assess the similarity between habitats and the differences in taxonomic composition between periods. Results: We collected a total of 802 individuals from 15 species and 4 taxonomic units, 5 genera, and 4 tribes. Notably, this may be the first records of Wyeomyia felicia Dyar &amp; Núñez Tovar and Culex derivator Dyar &amp; Knab from Ecuador. Additionally, the presence of Culex dunni Dyar and Psorophora ferox von Humboldt (both recognized as vectors) was correlated with increased rainfall. Conclusions: The abundance of mosquitoes, including potential vector species, increased during the rainy season, indicating a higher risk of pathogen transmission. However, the relationship between rainfall amount and diversity patterns is not well-defined.

Checklist, distribution, diversity, and rarity of mayflies (Ephemeroptera) in Slovakia.

Despite the essential role of mayflies (Ephemeroptera) in freshwater ecosystems and their long-term use in research and routine biomonitoring in the Carpathian and Pannonian ecoregions, their distribution data are fragmentary and outdated. All published and unpublished data on mayflies from Slovakia was gathered and a database of > 15,000 species records from 2206 localities built with the aims (i) to critically revise available data and assess the completeness of the species inventory, (ii) to identify hotspots of species diversity, and (iii) to provide a benchmark for assessment of species rarity and conservation status in the region. After the critical revision of the data covering more than 100 years, the occurrence of 109 mayfly species in Slovakia was confirmed. The species inventory appears to be nearly complete, as evidenced by the rarefaction curve and a nonparametric species richness estimator. The highest mayfly gamma diversity was recorded below 500 m a.s.l. and in streams of the fifth order, which can be considered hotspots of mayfly diversity in the region. Six species were last recorded before 1990 and thus can be considered extinct in Slovakia. Twenty-nine species could be classified as very rare, with their occurrence frequency decreasing with increasing altitude and most of them being restricted to large lowland rivers and stagnant water habitats in their floodplains. In conclusion, our study provides comprehensive data on key freshwater bioindicators and suggests increasing conservation priorities, especially in lowland river floodplains occupied by several very rare mayfly species.

Convergent evolution of dark, ultraviolet-absorbing cuticular pigmentation in a new Afro-Oriental Echiniscus brunus species complex (Heterotardigrada: Echiniscidae)

Abstract Green, brown and black pigments are uncommon in the otherwise typically yellow to orange Echiniscidae. Viridiscus, a genus currently represented by a handful of species, in which cuticular coloration varies from a light green through dark green to almost black, has been an exception. Here, we uncover a new echiniscid lineage from the primeval subtropical and tropical rainforests of India and Tanzania, comprising three species with a caramel/brown body. Given that both Viridiscus and the new species complex lack dorsolateral trunk appendages and share dark cuticular pigmentation, they may be mistaken for each other. However, a closer inspection of the dorsal cuticular sculpture and molecular phylogenetic analyses indicate that the new complex belongs within the Echiniscus spinulosus morphogroup. Thus, the presence of dark pigments in two indirectly related lineages is evidence for the convergence of dark cuticular coloration in limno-terrestrial heterotardigrades. We detected three species in the new complex: Echiniscus brunus sp. nov., from the Western Ghats (Tamil Nadu, India), and two other candidate species, Echiniscus aff. brunus sp. can. 1 and Echiniscus aff. brunus sp. can. 2, from India and Tanzania, respectively. We refrain from describing the two latter species formally because they exhibit little or no morphological differences, which is yet another clear case of the crucial role of DNA barcoding in an accurate estimation of tardigrade species richness.