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We modeled feeding of the Atlantic salmon (Salmo salar) parr to understand the role of global (cross‐continental) and regional (river) spatial scales for delineating feeding patterns. The diet composition differed between Eurasia and North America populations. Geographic location (latitude and elevation) had an influence for the most common prey (Ephemeroptera, Diptera and Plecoptera). The random factors (sampling location and river) had a strong explanatory power in our models, suggesting that local drivers may override the effects of large‐scale drivers. [ABSTRACT FROM AUTHOR]

Large rivers are difficult to sample due to their size yet critical to monitor because humans heavily rely upon and alter them. Aquatic invertebrates are commonly used to assess the ecosystem quality of streams, but methods to sample large rivers are underdeveloped. We sampled aquatic invertebrates using a Hess sampler and rock baskets in the Snake River near Jackson, Wyoming, USA. Hess samples collected more aquatic invertebrate taxa and a higher proportion of Ephemeroptera, Plecoptera, and burrowing taxa. Rock baskets collected a higher proportion of Trichoptera, filterers, and clinging taxa. Bioassessment metrics differed between sampling methods; richness, diversity, evenness, Ephemeroptera, Plecoptera, and Trichoptera (EPT), and Hilsenhoff's biotic index produced higher values in Hess samples, and percent EPT was higher in rock baskets. Non-metric multidimensional scaling and analysis of similarity indicated that the samplers collected different assemblages (p < 0.001). The standard error of total invertebrate density was smaller and most taxa were collected with seven replicate samples. Understanding how sampling methods alter the aquatic invertebrates collected will help managers develop monitoring protocols that are best suited to the river and collect the most unbiased invertebrate assemblages. [ABSTRACT FROM AUTHOR]

So far, species of the genus Isonychia Eaton, 1871 have been reported to have transparent or partially pigmented wings, particularly their hindwings. A new species, I. fuscimarginata sp. n., recently collected from southern China, shows a different case. Both its forewings and hindwings have striking reddish brown to chocolate margins and stripes. Besides that, the entirely dark brown forelegs, shortened but apically widened male penises, and the colour and spine patterns of nymphal gills are useful characters for identification. This new species enriches the colour pattern of the genus Isonychia and the family Isonychiidae. [ABSTRACT FROM AUTHOR]

We identified groups of mayfly species that share microhabitats in eastern Cuban streams by sampling during rainy and dry seasons in four microhabitats in pools (cobbles, sand, leaf litter and bank vegetation) and one microhabitat (cobbles) in riffles. A total of 20 species and three morphospecies were found. Species similarity in habitat use was analysed using k-means clustering. Overall, the highest number of individuals was collected in cobbles in riffles, followed by cobbles in pools. Five species groups, labelled from I to V, were identified based on their primary microhabitat use. Two groups (I and V) included species with a generalist pattern of habitat use, but differing in seasonality. Species in remaining groups tend to concentrate in specific microhabitats. Species of groups II and IV use mostly cobbles in riffles and in pools, respectively, while species in group III concentrate in sand during the rainy season. Our results allowed to identify the species most vulnerable to alterations of the hydrologic regimen. [ABSTRACT FROM AUTHOR]

The mayfly Ephemera lota Navás, 1934 was described based on subimagines, and the imagines and nymphs have not been known so far. For the first time, we provide descriptions of adults and nymphs using recently collected material. Based on their morphology, the species diagnostic characters are imaginal abdomen without transverse line, penis with finger-like apex, hindwing without any dot; nymphal frons with deep anterior emargination, two mandibular tusks subequal in length. Significantly, forewings of this species have variable MP2 base: from independent to fusing with CuA in different specimens through the other characters and barcoding data confirm all specimens belong to the same species. Due to the holotype lost, a neotype of the species is designated and subimagines are re-described. [ABSTRACT FROM AUTHOR]

Ephemera (Ephemera) spilosa Navás, 1936 was first described from China at the imaginal stage. Subsequently, in 2008, the nymph of E. spilosa was described from Vietnam. These are the only two known occurrences of this species. This study contributes the first record of E. spilosa from Thailand and provides a distribution map for this species.

Caenis ulmeriana Malzacher, 2015 is recorded for the first time from the Western Ghats, India. Prior records of this species encompass Java, Sumatra, Thailand, Myanmar, and the Philippines. Notably, the Indian population of C. ulmeriana showcases variability, including slight changes in the shape of forceps in the male subimago and increased denticulation in the midclaw, a reduced number of setae in the Y-ridge of tergalius II, and differing shape of sternum IX in the larvae compared to other continental and island populations. The species number of Caenis Stephens, 1835 has now increased to twelve in India. A distributional map detailing the range of C. ulmeriana in the Oriental region is also provided herein.

Baetiella muchei (Braasch, 1978) is recorded for the first time from the Neeru stream of Jammu and Kashmir, India. The variability in larval characters such as size, the shape of the labrum, and the number of the sub-marginal arc of setae in the labrum differs from 12 to 22, degree of fusion of the mandibular incisors, spines on the distal margin of the tergites, distal margin of the paraproct, and the length of cerci are observed from the Indian population when compared to the type specimens. The species number of Baetiella Uéno, 1931 has now increased to six in India. A distributional map of this species is also provided.

Mayflies, recognized for their hemimetabolous life cycle and ephemeral adult phase, exhibit diverse larval forms categorized as burrowing, flattened, swimming, and creeping. Ameletus inopinatus Eaton, 1887, a member of the Ameletidae family within the order Ephemeroptera, undergoes aquatic development and is commonly found in the tranquil stretches of small rivers or streams, particularly among stones and boulders. This study focused on A. inopinatus nymphs collected from Yarımca village in Eskişehir, Turkiye. Employing molecular techniques and culture-independent methods, rRNA-based analyses were conducted to characterize the archaeal and bacterial communities within the nymphs' gut. Microbial DNA was extracted from the gut, and PCR amplification targeted 16S rRNA genes for both Archaea and Bacteria domains. Denaturing gradient gel electrophoresis (DGGE) separated the amplified products, yielding six distinct bands with Bacteria-specific primers. The subsequent analysis of 16S rRNA sequencing from DGGE bands revealed a predominance of the Proteobacteria phylum within the gut lumen. Complementary investigations into prokaryotic diversity employed fluorescence in situ hybridization (FISH) and 4',6-diamidino-2-phenylindole (DAPI) staining. Total DAPI cell counts indicated a microbial cell population of approximately 106 ± 0.18 in the samples. The overarching conclusion derived from these findings is that the microbial community within the Ameletus inopinatus gut is predominantly associated with the Bacteria domain. Recognizing the ecological importance of this symbiotic relationship, the coexistence of mayflies with specific microbial communities is emphasized, underscoring the potential mutualistic roles played by these microorganisms in the life cycle and ecological dynamics of Ameletus inopinatus. This research not only contributes valuable insights into the microbial ecology of mayfly nymphs but also underscores the significance of understanding the intricate relationships between insects and their associated microorganisms for broader ecological perspectives and potential applications in environmental management. [ABSTRACT FROM AUTHOR]

Excess fine sediment (particles <2 mm) delivery and deposition in freshwater systems is a significant factor in structuring aquatic communities and populations.Invertebrate gill surfaces can become covered with fine sediment, potentially compromising osmoregulatory function.Ionocytes are specialised structures for osmoregulation found on the tracheal gills of mayflies. The number of cells has been shown to change in order to maintain osmoregulatory demands under environmentally variable conditions.To investigate whether ionocytes vary in response to fine sediment pressure, individuals of Baetis rhodani were collected from two high and low fine sediment cover sites, respectively, in the UK. Tracheal gills were subsequently examined for the number of ionocytes present on the upper and lower gill surfaces, standardised by gill size.Results indicated that the number of ionocytes was significantly higher for mayflies collected from areas with high fine sediment cover. High fine sediment sites were also characterised by lower altitude and dissolved oxygen concentrations. Mayfly gills collected from high sediment cover sites were also significantly larger than those collected from low sediment sites.The results illustrate the potential for mayfly larvae to demonstrate phenotypic plasticity to the pressures associated with fine sediment but that these responses are likely dependent on the composition of fine sediment deposits (organic or mineral) and associated oxygen concentrations. [ABSTRACT FROM AUTHOR]

Caenis ulmeriana Malzacher, 2015 is recorded for the first time from the Western Ghats, India. Prior records of this species encompass Java, Sumatra, Thailand, Myanmar, and the Philippines. Notably, the Indian population of C. ulmeriana showcases variability, including slight changes in the shape of forceps in the male subimago and increased denticulation in the midclaw, a reduced number of setae in the Y-ridge of tergalius II, and differing shape of sternum IX in the larvae compared to other continental and island populations. The species number of Caenis Stephens, 1835 has now increased to twelve in India. A distributional map detailing the range of C. ulmeriana in the Oriental region is also provided herein. [ABSTRACT FROM AUTHOR]

Mayflies (Ephemeroptera) are among the crucial water and habitat quality bioindicators. However, despite their intensive long‐term use in various studies, more reliable mayfly DNA barcode data have been produced in a negligible number of countries, and only ~40% of European species had been barcoded with less than 50% of families covered. Despite being carried out in a small area, our study presents the second‐most species‐rich DNA reference library of mayflies from Europe and the first comprehensive view from an important biodiversity hotspot such as the Western Carpathians. Within 1153 sequences, 76 morphologically determined species were recorded and added to the Barcode of Life Data System (BOLD) database. All obtained sequences were assigned to 97 BINs, 11 of which were unique and three represented species never barcoded before. Sequences of 16 species with high intraspecific variability were divided into 40 BINs, confirming the presence of cryptic lineages. Due to the low interspecific divergence and the non‐existing barcoding gap, sequences of six species were assigned to three shared BINs. Delimitation analyses resulted in 79 and 107 putative species respectively. Bayesian and maximum‐likelihood phylogenies confirmed the monophyly of almost all species and complexes of cryptic taxa and proved that DNA barcoding distinguishes almost all studied mayfly species. We have shown that it is still sufficient to thoroughly investigate the fauna of a small but geographically important area to enrich global databases greatly. In particular, the insights gained here transcend the local context and may have broader implications for advancing barcoding efforts. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ephemeroptera nymphs are globally recognized for their sensitivity to decreased oxygen levels in aquatic habitats, leading to their frequent use as biological indicators in various monitoring projects worldwide. However, studies utilizing Ephemeroptera in Indonesia have remained largely unknown. This study aims to document the use of Ephemeroptera as bioindicators for assessing surface water quality status in Indonesia. This includes understanding their distribution and the types of surface water habitats that have been investigated using this order as an indicator. There are 47 published papers utilizing Ephemeroptera as a bioindicator for assessing surface water health in Indonesia which were gathered through Google Scholar. Bioindicator studies utilizing Ephemeroptera in Indonesia have only emerged in the last decade. Currently, research on Ephemeroptera as bioindicators for surface waters has predominantly focused on Java Island. Regions on other islands remain relatively understudied, particularly in eastern Indonesia. River habitats lead in the number of observed habitat types. With this knowledge, future research on utilizing Ephemeroptera as bioindicators should prioritize areas beyond Java Island and focus on habitat types that have been less explored, including irrigation canals, paddy fields, waterfalls, wetlands, and springs. [ABSTRACT FROM AUTHOR]

Freshwater aquatic ecosystems are threatened globally. Biological monitoring is required to deliver rapid and replicable assessment of changes in habitat quality. The Ephemeroptera, Plectoptera, Trichoptera (EPT) index is a globally recognised rapid bioassessment that measures taxa richness of three insect orders whose larvae are considered sensitive to freshwater habitat degradation. South-western Australia contains threatened freshwater ecosystems but has depauperate EPT fauna and high endemism, potentially reducing the capacity of the EPT index to track degradation. This study investigated if EPT species richness, composition or individual species tracked physical or chemical river degradation in three catchments in south-western Australia. We sampled EPT fauna and measured water chemistry, erosion, sedimentation, riparian vegetation cover and instream habitat at 98 sites in the winters of 2007 and 2023. We found 35 EPT taxa across the study area with a median number of species per site of two. EPT species richness had weak positive associations with a composite water quality index and dissolved oxygen and weak negative associations with electrical conductivity and total nitrogen. No association was found between physical and fringing zone degradation measures and EPT species richness. EPT community structure generally did not distinguish between sites with high or low degradation levels. The presence of the mayfly Nyungara bunni tracked salinity, dissolved oxygen and nitrogen levels, but its usefulness as a bioindicator could be limited by its restricted range. This study suggests that the EPT index would need modification or combination with other indices to be a useful rapid bioassessment in south-western Australia. [ABSTRACT FROM AUTHOR]

The impact of two high‐head dams on macroinvertebrate communities within the regulated reaches of the Wujiang River in China was explored, using longitudinal monitoring data spanning from 2006 to 2016. In this study, we set up 10 sampling sites categorized into four areas based on different stressors and defined three stages based on the timeline of dam construction. Our findings revealed significant changes in community composition before and after dam impoundment. While certain original dominant taxa, such as Rivularia globosa and Lithoglyphopsis ovatus, remained dominant throughout the stages, mayflies and caddisflies nearly vanished in the downstream reaches of the dams. This trend was accompanied by the disappearance of taxa with low adaptability and the emergence of tolerant taxa downstream of the dams. Additionally, typical limnological taxa colonized the inundated reaches. Dam impoundment affected not only macroinvertebrate community composition but also diversity. In this study, the recovery effect of communities downstream of dams was not observed due to the limited distance, but the presence of Wujiangdu Dam upstream of the two dams for over 20 years makes us believe that in a large river system, macroinvertebrate communities downstream of high‐head dams may fully recover if the distance from the dams is long enough. The original and vulnerable species R. globosa, which demonstrated remarkable adaptability and thrived downstream of dams, should be further studied in the future. [ABSTRACT FROM AUTHOR]

Rapid changes in thermal environments are threatening many species worldwide. Thermal acclimatisation may partially buffer species from the impacts of these changes, but currently, the knowledge about the temporal dynamics of acclimatisation remains limited. Moreover, acclimatisation phenotypes are typically determined in laboratory conditions that lack the variability and stochasticity that characterise the natural environment. Through a distributed lag non‐linear model (DLNM), we use field data to assess how the timing and magnitude of past thermal exposures influence thermal tolerance. We apply the model to two Scottish freshwater Ephemeroptera species living in natural thermal conditions. Model results provide evidence that rapid heat hardening effects are dramatic and reflect high rates of change in temperatures experienced over recent hours to days. In contrast, temperature change magnitude impacted acclimatisation over the course of weeks but had no impact on short‐term responses. Our results also indicate that individuals may de‐acclimatise their heat tolerance in response to cooler environments. Based on the novel insights provided by this powerful modelling approach, we recommend its wider uptake among thermal physiologists to facilitate more nuanced insights in natural contexts, with the additional benefit of providing evidence needed to improve the design of laboratory experiments. [ABSTRACT FROM AUTHOR]

Miroculis (Ommaethus) Savage and Peters, 1983 (Ephemeroptera, Leptophlebiidae) is reviewed based on fresh material from Southeastern Brazil and on type specimens. Miroculis (Ommaethus) cipoensis sp. n. is described based on male and female imagos from Serra do Cipó, Minas Gerais State, Brazil. It can be distinguished from other species of the subgenus based on the following characteristics: forewings with membrane brown and dark brown mark around cross veins; hind wing uniformly brown; forceps segment I light brown, segment II and III lighter; penis lobe long (at least ⅔ of forceps segment I) and apically rounded and curved on apical ¼; length of body between 5.0 and 6.3 mm. Photographs of fresh material belonging to M. (O.) froehlichi Savage and Peters, 1983 and M. (O.) mourei Savage and Peters, 1983 are provided, clarifying the boundaries between the existing species of the subgenus. Based on that, M. (O.) misionensis Domínguez, 2007 is considered a junior synonym of M. (O.) mourei. A key to the male imagos of the subgenus is presented, as well as a distributional map with updated records of the species. [ABSTRACT FROM AUTHOR]

The eight northeastern Nearctic species of Rhithrogena are principally known from descriptions of male imagos. Nymphs of several species (R. amica, R. anomala, R. brunneotincta, and R. gaspeensis) remain undescribed and existing keys are incomplete or regionally restricted. The inability to accurately determine nymphs of the northeastern species of Rhithrogena has been a long-standing problem for ecologists, aquatic biomonitoring programs, efforts to monitor effects of climate on sensitive aquatic taxa, and now efforts to assess conservation needs of aquatic insect species. Nymphs of all northeastern species of Rhithrogena (except for that of R. gaspeensis, which remains unknown) are either described for the first time or redescribed in a fully comparative manner. Diagnoses for each species and a new illustrated key to late instar nymphs are presented. Two major taxonomic outcomes are: (1) clarification of the taxonomic status of R. jejuna Eaton s.s. and subsequent recognition of R. undulata (Banks) as a new subjective junior synonym of R. jejuna Eaton s.s.; and (2) recognition of a new species (R. serpenglena sp. n.) that was previously incorrectly identified as R. jejuna Eaton. Lastly, new distribution records, information on species ranges, and notes of aquatic habitats of nymphs are also presented. [ABSTRACT FROM AUTHOR]

Three new fossil mayfly (Ephemeroptera) larvae from the Redmond Formation (Cenomanian) of Newfoundland and Labrador, Canada, are described: Alatuscapillus icarus gen. et sp. nov. (family Oligoneuriidae), Cruscolli sheppardae gen. et sp. nov. (family Heptageniidae), and Protoligoneuria borealis sp. nov. (family Hexagenitidae). This discovery marks the first juvenile insect nymphs to be described from this formation and helps fill gaps in our understanding of the global and temporal distribution of mayflies during the Cretaceous period. Of these, C. sheppardae marks the oldest occurrence of the family Heptageniidae in the fossil record, while A. icarus and P. borealis mark the first fossil occurrences of the families Oligoneuriidae and Hexagenitidae in North America. The anatomy, preservation, and behaviour of these new mayfly species inferred from modern taxa consolidate the hypothesis that the Redmond Formation's palaeoenvironment was lacustrine in nature. [ABSTRACT FROM AUTHOR]

As part of ongoing exploration of the mayflies in the hill streams of northeast India, Rhoenanthus (Potamanthindus) sapa Nguyen and Bae 2004 was reported as a new record based on larval collections from Meghalaya, India. [ABSTRACT FROM AUTHOR]

This paper gives a review on the bio-inspired optimization methodology known as mayfly (MA) algorithm in order to resolve issues in optimization techniques. It is a newly formed meta-heuristic optimization algorithm that focuses on the movements of masculine and feminine mayflies. It is encouraged from flying behaviour also the methods of mating in mayflies. With the help of a realistic-world separate flow planning issue along with the coupling behaviour in numerous objective optimizations, the performance of the mayfly algorithm (MA) is well evaluated. Some of the implementations of this algorithm are discussed in this paper: Bearing fault diagnosis based on the mayfly algorithm, optimizing the performance of PEMFC, Covid diagnosis, wind speed optimization, improving the scheduling of solar wind speed using mayfly optimization, detecting fault in the wind turbine gearboxes, patterning in the array antennas with the help of optimization and so on. One of the main advantages of the MA is that it combines the other optimization algorithms namely swarm optimization (PSO) with the evolutionary optimizations (GA). The motion of the mayflies that resemble nuptial dance model along with the arbitrary flight helps in the improvement of the stability within the exploration and exploitation methods. In addition, allows escape from the community peak. All the above work reviewed shows promising results from the algorithm. More work can be carried out using this algorithm in future. [ABSTRACT FROM AUTHOR]

Hydromorphological degradation is one of the most common stressors to freshwater ecosystems nowadays. Rivers lose riparian vegetation, habitat heterogeneity, natural flow velocity, etc., due to hydromorphological alterations. We analyzed macroinvertebrate communities in a wide range of hydromorphological conditions – from near natural sites to significantly altered water bodies, focusing on Ephemeroptera, Plecoptera, and Trichoptera (EPT). Considering that the EPT group is a quite sensitive and generally stenovalent group, we wanted to examine which of the hydromorphological pressures affects them the most. We also wanted to identify indicator taxa for different levels of degradation: minor, moderate, and severe. We collected samples from 84 karst rivers sites in Croatia. We found 52 taxa of EPT (Ephemeroptera – 21, Plecoptera – 11, Trichoptera – 20). Changes in river morphology proved to be the most important stressor affecting the distribution of the EPT group. Hydrological regulation did not show significance toward the EPT community, possibly due to the karst nature of the rivers studied. The most sensitive EPT taxa were those with the greatest preference for macrophytes and lithal habitats. More tolerant EPT taxa were those with a wide range of habitat preferences and/or taxa that feed on particulate organic matter. HIGHLIGHTS Our research underscores the pivotal role of morphological changes in rivers as the primary stressor impacting EPT communities.; We identify indicator taxa for different levels of hydromorphological degradation.; Focusing on the understudied karst rivers, our research provides unique insights into the complex and heterogeneous habitats of these ecosystems.; Reliable metrics for assessing river health.;

Freshwater insects like Ephemeroptera are more comprehensive and direct indicators of the biological impacts of pollution. During the study period (2018-2020), a total of 4,374 individuals of mayflies were collected and categorized under nine families, 27 genera, and 36 species. The family Leptophlebiidae was found dominant with 13 species. In the post-monsoon season, a higher species diversity of Ephemeroptera was noticed in the river's upstream section with a Shannon-Wiener index value of H' = 1.814. ANOVA revealed a significant difference (p <0.05) except for Ephemeridae (p >0.05). Protecting rivers requires a holistic approach and collaboration among stakeholders is essential for successful implementation. [ABSTRACT FROM AUTHOR]

Simple Summary: As one of the burrowing mayfly groups with large mandibular tusks, the phylogenetic relationships within Potamanthidae are always controversial. There are at least two opposite hypotheses for mayfly grouping: Potamanthidae + (Ephemeridae + Polymitarcyidae) and (Potamanthidae + Ephemeridae) + Polymitarcyidae. Because of the indeterminate origin time of this group, the present study aimed to reconstruct the phylogenetic relationship and explore the origin time of Potamanthidae based on mitochondrial (mt) genomes. In addition, the protein-coding genes (PCGs) of these mt genomes may undergo positive selection when these species live in low-temperature environments. Potamanthidae belongs to the superfamily Ephemeroidea but has no complete mt genome released in the NCBI (except for two unchecked and one partial mt genome). Since the sister clade to Potamanthidae has always been controversial, we sequenced seven mt genomes of Potamanthidae (two species from Rhoenanthus and five species from Potamanthus) in order to rebuild the phylogenetic relationships of Potamanthidae in this study. The divergence time of Potamanthidae was also investigated by utilizing five fossil calibration points because of the indeterminate origin time. In addition, because Rhoenanthus coreanus and Potamanthus luteus are always in low-temperature environments, we aimed to explore whether these two species were under positive selection at the mt genome level. Amongst the 13 PCGs, CGA was used as the start codon in COX1, whereas other genes conformed to initiating with an ATN start codon. From this analysis, UUA (L), AUU (I), and UUU (F) had the highest usage. Furthermore, the DHU arm was absent in the secondary structure of S1 in all species. By combining the 13 PCGs and 2 rRNAs, we reconstructed the phylogenetic relationship of Potamanthidae within Ephemeroptera. The monophyly of Potamanthidae and the monophyly of Rhoenanthus and Potamanthus were supported in the results. The phylogenetic relationship of Potamanthidae + (Ephemeridae + Polymitarcyidae) was also recovered with a high prior probability. The divergence times of Potamanthidae were traced to be 90.44 Mya (95% HPD, 62.80–121.74 Mya), and the divergence times of Rhoenanthus and Potamanthus originated at approximately 64.77 Mya (95% HPD, 43.82–88.68 Mya), thus belonging to the late Pliocene Epoch or early Miocene Epoch. In addition, the data indicated that R. coreanus was under negative selection and that ATP8 and ND2 in Potamanthidae had a high evolutionary rate. [ABSTRACT FROM AUTHOR]

The genus Languidipes is currently represented by three species distributed in southeastern Asia, India, and Sri Lanka. Languidipes corporaali is the most widely distributed species, and both, male and female imagos, as well as nymphs, are known. In contrast, the other species, L. taprobanes and L. lithophagus, are only known from nymphs. Here, we describe a new species, Languidipes janae sp nov, based on male imagos collected from Borneo, Indonesia. This new species is characterized by the presence of ommation on mesonotum, and penis almost completely divided, with sub-quadrate base and a small outer projection basal to the long and slender distal arms. This constitutes the first record of the genus for Borneo. A cladistic analysis of the subfamily Asthenopodinae supports its taxonomic status. [ABSTRACT FROM AUTHOR]

One of the primary challenges in biodiversity conservation is the limited knowledge of the taxonomy and geographical distribution of species, particularly in megadiverse regions such as the AmazonIn this context, the present study aimed to mitigate the Linnean and Wallacean shortfalls within the Family Leptophlebiidae (Ephemeroptera: Insecta) in the Brazilian Amazon, identify priority areas for conducting faunal inventories and enhance taxonomic knowledge of this group.Utilizing both primary Leptophlebiidae data collected in the state of Pará, and secondary data compiled from the literature on species occurring in the Amazon, we employed Species Distribution Modelling to identify areas with higher potential species richness and priority areas for faunal inventories in the Brazilian Amazon of the family.For the primary data, 2,120 specimens were identified, representing 16 genera and 28 species. Among the 28 species analysed, 7 constitute new records for the state of Pará. Additionally, two new genera, five new species and six morphospecies were identified, significantly expanding the taxonomic landscape of the family in the state. Maps depicting potential species richness and priority areas for faunal inventories in the Brazilian Amazon generated from the Modelling indicated that the states of Pará and the western region of Maranhão exhibit high potential species richness, with overlapping areas identified as priorities for Leptophlebiidae faunal inventories.In this context, this study represents a substantial advancement in the taxonomic knowledge of Leptophlebiidae in the state of Pará and the Amazon, underscoring the urgency of research and biodiversity conservation efforts for the group in the region. Furthermore, the identification of new taxa emphasizes the need for ongoing collaborative efforts to mitigate Linnean and Wallacean shortfalls. [ABSTRACT FROM AUTHOR]

Pesticide exposure patterns tested in laboratory bioassays often do not match real-world pesticide exposure profiles in edge-of-field waterbodies. Toxicokinetic–toxicodynamic (TKTD) models are therefore increasingly used, as they allow for predictions of the toxic effects under actual time-variable field exposures. The TKTD models from the General Unified Threshold models of Survival (GUTS), for example, are considered ready for use by regulators for calculating the survival rates for any time-variable exposure profile. However, questions remain regarding their predictive power for compounds showing increased toxicity over time, such as neonicotinoid insecticides. The aim of the present study was therefore to compare the GUTS-predicted 28 d toxicity values of three neonicotinoids (imidacloprid, clothianidin, and thiamethoxam) for the common New Zealand mayfly genus Deleatidium spp. with those observed in a previously published study. Overall, the GUTS modeling results underestimated the toxicity values derived experimentally. From the three neonicotinoids, clothianidin showed the best fit between the estimated and observed 28 d LC50 (median-lethal-concentration) values. Shortcomings of the modeling exercise, future research needs, and implications for the application of GUTS models in regulatory risk assessment are discussed. [ABSTRACT FROM AUTHOR]

Cincticostella jianchuan sp. nov. from Dali Bai Autonomous Prefecture, Yunnan Province, China, is described based on chorionic structure, nymph, and winged stages. The new species is closely related to C. fusca (Kang & Yang, 1995), but it can be distinguished in the male imago stage by its mesonotum and penes morphology, coloration, and the forking point of the stem of MA+Rs on the forewing; in the nymph stage, it can be distinguished by the length of the posterolateral projections of abdominal segment IX and the setation of the abdominal terga. Compared to other congeners, nymphs and male imagoes of the new species and C. fusca share several morphological characteristics, such as a larger body, mesothorax with medially notched anterolateral projections, forefemur without a subapical band of transverse spines of the nymphs, the area between C, Sc and R1 of the forewings distinctly pigmented, and an apical sclerite on the ventral face of the penes of the male imagoes, supporting the proposition of a new species complex, the jianchuan complex. The systematics of Cincticostella and related genera are discussed briefly. [ABSTRACT FROM AUTHOR]

The State of Maranhão, located in northeastern Brazil, has a great biodiversity due to the complex of biomes that constitutes its territory. Due to the paucity of research in the area, there are gaps in knowledge of the local fauna. This work aims to contribute to the knowledge of the order Ephemeroptera. Two species of Baetidae, Callibaetis nigracyclus (Cruz et al. J Nat Hist 48:591–660, 2014) and Cloeodes auwe (Salles et al. Biota Neotrop 4:1–8, 2004a), and one species of Leptophlebiidae, Hermanella mazama (Nascimento, Mariano and Salles, 2012) are here registered from the State. It is noteworthy that the genus Cloeodes Traver 1938 and Hermanella Needham and Murphy (Lloyd Entomol Ser 24:1–79, 1924), still do not have records from the State and it is also worth mentioning that all new records represent an important geographic extension. [ABSTRACT FROM AUTHOR]

Baetiella muchei (Braasch, 1978) is recorded for the first time from the Neeru stream of Jammu and Kashmir, India. The variability in larval characters such as size, the shape of the labrum, and the number of the sub-marginal arc of setae in the labrum differs from 12 to 22, degree of fusion of the mandibular incisors, spines on the distal margin of the tergites, distal margin of the paraproct, and the length of cerci are observed from the Indian population when compared to the type specimens. The species number of Baetiella Uéno, 1931 has now increased to six in India. A distributional map of this species is also provided. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on material recently collected in northern Thailand, the present study provides an updated of the genus Baetiella, including Gratia. It comprises six species in Thailand, three of them being new species: Baetiella (Gratia) narumonae, Baetiella (Gratia) sororculaenadinae, Baetiella (Baetiella) bispinosa, Baetiella (Baetiella) baei sp. nov., Baetiella (Baetiella) lannaensis sp. nov. and Baetiella (Baetiella) bibranchia sp. nov. Baetiella (Baetiella) baei sp. nov. can be distinguished from other species by the reduction of the posteromedian protuberances on abdominal tergites I–III, the asymmetrical coniform terminal segment of labial palp, the distal margin of abdominal sternites VII–X each with a row of long, spatulate setae, the dorsal margin of femur with two long, robust setae distally. Baetiella (Baetiella) lannaensis sp. nov. is diagnosed by the posteromedian protuberances present on tergites I–VIII, dorsal margin of femur with a regular row of long, rounded, ciliated setae and body surface covered with numerous, dense, rounded scale-like setae. Baetiella (Baetiella) bibranchia sp. nov. can be separated from other species by coxal gills present at the base of forelegs and midlegs. The molecular study based on the mitochondrial gene COI and a larval key to species of Thai Baetiella are also provided. [ABSTRACT FROM AUTHOR]

The aim of the study was to test the significance of the EPT index in the water quality assessment of three types of water bodies in hilly and mountainous region of Serbia. The aquatic macroinvertebrate community was dominated by the group of insects, of which 95 taxa represent the EPT group. We compared the obtained values of biological indices used for the assessment of water quality according to the national legislation with the overall status assessment represented by the ecological quality classes (EQC). The results of the Spearman correlation test showed a negative correlation of EQC with the EPT index, BMWP score, H′, total number of taxa and number of sensitive taxa, while a positive correlation was observed for the values of SI and Tubificinae %. The values of EQC and biological indices were subjected to principal component analysis (PCA). The results showed that the parameters that contributed most to the differences were the EPT index, the BMWP score and the number of sensitive taxa. The results indicate that the EPT index is an excellent indicator of changes in water quality and an important tool for the ecological categorization of water bodies in mountain regions. [ABSTRACT FROM AUTHOR]

Based on a well-preserved male imago, a new genus and species Oculephemera mazhenxingi n. gen. et n. sp. of Ephemeroptera are presented in this study. For its distinct characters on head, wings, legs and genitalia, especially the autapomorphies of fused turban eyes and three distal segments of forceps, we erect a new family Oculephemeridae n. fam. herein as the sixth ephemeropteran family discovered from Kachin amber. All the distinguishable characters of the new taxa are illustrated and described; detailed comparisons between related families are also given. The new taxa not only represent a unique clade of mayflies but also give us a chance to modify somehypothesess of the origin, evolution and dispersal of several related lineages. [ABSTRACT FROM AUTHOR]

In larvae of burrowing mayflies (Ephemeroidea), mandibular tusks are generally associated with burrowing and/or feeding. This study reports, for the first time, the use of mandibular tusks as weapons in the aggressive behavior of the burrowing mayfly Rhoenanthus coreanus (Yoon and Bae, 1985) (Potamanthidae). The larvae used their tusks as weapons in combat behaviors such as tusking, which was observed in 60.81% and 62.98% of the studied males and females, respectively. Most cases involved combat by tusking between females (70.45%), followed by combat between males (21.60%), and combat between male and female individuals (3.97%). Aggressive behavior was more common in female larvae with longer mandibular tusks. Positive relationships were observed between the number of cases of aggressive behavior (i.e., tusking) and the size of mandibular tusks in both male and female larvae (p < 0.001). Female larvae with large mandibular tusks (5.00 ± 0.50 mm) could use their tusks to lift their opponents in a manner similar to horned beetles. Contests typically occurred as a result of territorial conflict and served as a means to find or retain occupied shelters for feeding and hiding. [ABSTRACT FROM AUTHOR]

The family Baetiscidae Edmunds & Traver, 1954 is recognisable among mayflies due to its bizarre larvae, equipped with a robust and spiked thoracic notal shield covering part of the abdomen up to sixth segment. Originally being described as extant species from the USA and Canada, Baetiscidae were later found in the fossil record as well, specifically in Cretaceous of Brazil and Eocene Baltic amber. An enigmatic piece of fossil evidence are two larvae from the Early Cretaceous Koonwarra Fossil Bed in Australia, which have been presumed as attributable to Baetiscidae and briefly discussed in previous studies. In the present contribution, we reinvestigate these fossils and confirm their attribution to the family Baetiscidae. These larvae are depicted and described as Koonwarrabaetisca jelligen. et sp. nov. and Koonwarrabaetisca duncanisp. nov. For both Cretaceous genera Protobaetisca Staniczek, 2007 and Koonwarrabaetiscagen. nov. we establish a new subfamily Protobaetiscinae subfam. nov. within the family Baetiscidae, based on the presence of markedly shortened thoracic sterna. The phylogenetic position of newly described subfamily is clarified using a cladistic analysis; Protobaetiscinae subfam. nov. forms a monophyletic clade, sister to Baetiscinae. The confirmation of the distribution of Baetiscidae in the Cretaceous of Australia suggests almost worldwide distribution of this family in the deep time. Given their limited dispersal abilities, this distributional pattern can be best explained by the Pangean origin for this family, moving the time of their origin at least to the Early Jurassic. The larvae of Koonwarrabaetiscagen. nov. exhibit the same ecomorphological specialization as the rest of Baetiscidae, that supporting with a high probability their lifestyle similar to extant Baetisca Walsh, 1862. The larvae probably lived in the flowing water with stony substrate densely covered by filamentous algae, and in the places of accumulation of dead plant and algae matter during the last instars. Thus, Koonwarrabaetiscagen. nov. could be the allochthonous component in mayfly fauna of the Koonwarra paleolake. [ABSTRACT FROM AUTHOR]

Little is known about the ecology of early instars of most aquatic insects, particularly their associations with microhabitat (<1 m2) features, such as sediment size distributions, other abiotic parameters, and the overall invertebrate community. This study sought to explore correlations between various biotic and abiotic parameters of a southern Colorado stream and the presence of early instars of Epeorus longimanus (Eaton) (Ephemeroptera: Heptageniidae). A total of 18 samples collected in 2007 and 2013 using a Hess sampler in riffle habitats were used to correlate the size of individuals with biological and abiotic characteristics of the stream, including sediment size, periphyton biomass, entrained organic matter, and the remainder of the benthic invertebrate community, all of which were measured using material from within the sampler. Results from both years showed that early instars of E. longimanus were more likely to be found in areas with smaller sediment sizes, higher live periphyton biomass (but lower overall organic matter), and lower densities of invertebrate predators. [ABSTRACT FROM AUTHOR]

The imaginal stages and eggs of the species Labiobaetis ancoralis Shi and Tong (2014) are first described and photographed based on reared materials from mature nymphs. In addition, its COI gene is sequenced and compared to other species in the same genus. Besides its nymphal labrum with submarginal spatulate-like bristles, abdomen with anchor-shaped markings, its imaginal diagnostic characteristics include slim hindwings with an indistinct costal process, and a cone-like projection between two base-widened forceps. The COI gene sequence of this species is close to L. atrebatinus. The morphological details provided in this research show that the males of the species L. ancoralis, like typical baetids, have reduced hindwings and penes, which have very limited value in classification, but their shapes of forceps can be used in future studies to identify the potentially diverse Chinese Labiobaetis species. [ABSTRACT FROM AUTHOR]

Morocco′s aquatic biodiversity remains insufficiently studied, especially in terms of invertebrates, with numerous gaps persisting, even in protected areas. This study combines our research with existing studies to provide a comprehensive list that encompasses both old and new faunistic and distributional records of three orders of aquatic insects (Ephemeroptera, Plecoptera and Trichoptera) in Tazekka National Park, located in the Eastern Middle Atlas Mountains. We provide an annotated list of 33 species, 23 of which were identified from 1400 specimens collected seasonally between the summer of 2018 and 2019 at 19 sampling sites. The remaining 10 species were identified from the literature sources and were not captured during this study. These 33 species belong to 31 genera and 21 families, comprising 9 species of Ephemeroptera, 14 species of Plecoptera, and 10 species of Trichoptera. The most interesting faunistic novelties consist of the capture of Epeorus cf. torrentium Eaton, 1881 (Ephemeroptera), Micrasema moestum Hagen, 1868 (Trichoptera), and Brachyptera auberti Consiglo, 1957, and Leuctra geniculata (Stephens, 1836) (Plecoptera), which are new records for the Middle Atlas. Furthermore, this work provided the first data on the Ephemeroptera of the Tazekka National Park. Additionally, 9 species of Plecoptera and Trichoptera were newly captured in this park. A chorological analysis revealed that most species are predominantly Mediterranean 61%, while those with a wider distribution occur in the Palearctic constitute the remaining 39%. In terms of endemism, 80% of the species recorded are endemic in the broad sense, with 44% classified as Ibero-Maghrebian, 31% endemic to the Maghreb, and 25% strictly Moroccan endemics. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study of river waters and the water flows of their tributaries is very important and necessary for the protection, use, and improvement of their condition. According to the Water Framework Directive (WFD, 2000) the use of benthic macroinvertebrates in river water quality monitoring is considered an efficient method. This study was conducted in 2019 in the Shushicë River, where its purpose was to assess the quality of river waters using the biotic index ASPT (BMWP) and the biotic index - SWRC. The sampling method used was based on the Kick net technique with a mesh size of 500 microns. From the sampling taken in four stations, 481 individuals belonging to two types (Arthropoda and Annelida), one class (Insecta), and one subclass (N/K Oligochaeta) were collected. The unidentified species belong to 8 orders (Ephemeroptera, Plecoptera, Trichoptera, Diptera, Coleoptera, Haplotaxid, Odonata, Hoplonemertea) and 28 families. Based on the results obtained from the calculation of the ASPT (BMWP) biotic index, stations I and III result in a "Clean" bio classification, and stations II and IV result in a "Partially clean" bio-classification. From the SWRC Biotic index calculations, the first station and the fourth station result in a bio classification of "Good", the second station results in a bio classification of "Clean", and the third station results in a bio classification of "Excellent" Based on the Biotic index ASPT (BMWP) and SWRC we can say that the Shushic River has good water quality, and partially with a slight organic pollution. [ABSTRACT FROM AUTHOR]

A new species belonging to the genus Habrophlebia Eaton, 1881 is described at the nymphal stage from the Rif Mountains of Morocco. This species presents unique features, such as the chorionic arrangement of the egg and the ornamentation of the posterior margin of abdominal tergites. It is compared to all west European Habrophlebia species and a table with discriminating characters is given. A phylogenetic reconstruction based on COI sequences fully supports the hypothesis of a new species in the Rif Mountains, with possible further distribution in southern Spain. [ABSTRACT FROM AUTHOR]

The Leptophlebiidae family of mayflies is diverse, with over 640 species and 140 genera worldwide. One of its subfamilies, Terpidinae, is restricted to the Neotropical region and consists of three genera, including Fittkaulus, which have four South American species. This paper redescribes the male imago and proposes a new synonym based on the rearing of nymphs identified as F. cururuensis collected in streams in the Caatinga and Amazon Forest regions of northern and northeastern Brazil. The male imago can be differentiate by having the following combination of characteristics: upper portions of eyes on short stalk; forewing with reddish brown maculae in costal, subcostal and radial sectors; abdomen whitish, with black stripes on posterior margin and dark brown maculae on lateral margins on terga I–VII; penis with proximal half fused; distal half divided, tubular and apically pointed, with latero-dorsal lobes. [ABSTRACT FROM AUTHOR]

To determine the Ephemeroptera (Insecta) fauna in the Pülümür and Ovacık districts of Tunceli province, a total of 2142 nymph samples were collected from 11 stations between March 2019 and July 2020. As a result, 22 taxa belonging to 10 genera of 5 families were identified. The Baetis (Baetis) vernus, B. (B.) lutheri, B. (B.) pavidus, B. (B.) melanonxy, B. (Rhodobaetis) milani, B. (R.) vadimi, Alainites muticus, Epeorus (Ironopsis) alpicola, E. (Caucasiron) znojkoi, Heptagenia (Dacnogenia) coerulans, Rhithrogena germanica, R. semicolorata, R. zelinkai, Ecdyonurus (Helvetoraeticus) picteti, Habroleptoides confusa, and Caenis macrura species were identified at the end of the study which are new records for the research area. [ABSTRACT FROM AUTHOR]

Understanding potential limiting factors affecting population growth of the endangered pallid sturgeon, Scaphirhynchus albus, is important in the upper (UMOR) and lower Missouri River (LMOR) basins. The UMOR is upstream of several reservoirs and generally has more natural habitat features, whereas the LMOR is downstream of these reservoirs and has been channelized to support navigation. In both sections, pallid sturgeon recruitment to age-1 is a concern, but hypothesized for different reasons. One hypothesis in the LMOR centers on food limitation for age-0 fish, which is not considered an issue in the UMOR, but evaluating this hypothesis is challenging given the rarity of age-0 pallid sturgeon. As a result, the related, more abundant shovelnose sturgeon (S. platorhynchus) has been considered as a potential surrogate to assess food-related hypotheses. Thus, the purpose of our study was to compare diets of age-0 sturgeon captured in 2016 from three reaches in the LMOR (Copeland, Langdon, and Lexington) with individuals captured from a reach in the UMOR (Williston) during the same year to provide additional context regarding potential food limitation in the LMOR. Consumption percentage (prey weight in the gut as a percentage of body weight) was similar among all reaches, but diet composition was different for the most downstream reach in the LMOR. Age-0 sturgeon in the UMOR reach as well as the two upstream LMOR reaches primarily consumed Diptera larvae along with Ephemeroptera nymphs. In contrast, age-0 sturgeon in the most downstream LMOR reach (Lexington) almost exclusively consumed Diptera larvae. These results may provide information on relative differences in prey availability between Lexington and the other upstream reaches but the similarity in consumption percentage values across all reaches provide further evidence that age-0 sturgeon are not food limited in the LMOR. Habitat alteration is a factor affecting fishes, including Scaphirhynchus sturgeon, in the Missouri River. The upper portion of this system is fragmented by several dams, yet contains relatively natural riverine habitat features between the reservoirs; the lower portion is heavily altered for barge navigation and bank stabilization. Feeding by age-0 sturgeon in the upper portion has generally been considered adequate for survival, whereas lack of prey has been suggested as limiting survival in the lower portion. We studied age-0 sturgeon prey use in the upper and lower portions of the Missouri River during 2016 and found minimal differences. [ABSTRACT FROM AUTHOR]

We found significantly different percentages of malformed nymphs in two contiguous populations of Serratella ignita (Poda, 1761) in a stream in the northwestern Italy. We suggest that this may be due to a marked difference in the environmental conditions and especially to the effect of pollution on the functional structure of the insect community. [ABSTRACT FROM AUTHOR]

Caenis limai sp. n. is described from the Veerapandi River in Theni, South India based on the larva, adult, and egg stages. The total number of Caenis species in India thereby is being augmented to eleven. The most closely related species to Caenis limai sp. n. is Caenis ulmeriana Malzacher, 2015 and the comparisons between both species are discussed herewith. The most important male subimaginal characters of Caenis americani Srinivasan et al., 2021 is described for the first time. [ABSTRACT FROM AUTHOR]