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One of the most vigorously debated issues in attention labs concerns the nature of the coupling between the sensory-motor system and covert spatial attention. Proponents of the Premotor Theory of Attention (PToA) claim that attention should be accounted for in terms of motor preparation for goal-directed actions such as eye or hand movements. For others, it is a supramodal psychological entity that is independent of our sensorimotor machinery. Both parties also seek to articulate this controversy in terms of cognitive science as a question of whether attention is embodied or disembodied cognition. The PToA is thought to advocate the embodiment of attention. We, however, are inclined to think that a more nuanced view of this conceptual framework is needed to yield some insights into how radical it actually is in terms of embodied cognition (EC). We argue that PToA still seems to bear some features of weak embodiment. Yet we suggest that it has the potential to build a stronger concept of attention as EC, but somewhat paradoxically this would require giving attention deflationary treatment and reconstructing it in other terms. We propose that the notion of pre-reflective intentionality might serve as an inspiration to this end. [ABSTRACT FROM AUTHOR]

The 15th International Symposium on Tardigrada, held in Kraków, Poland, brought together researchers from around the world to discuss various topics related to tardigrades. The symposium featured lectures, poster presentations, and a taxonomic roundtable, providing a platform for researchers to share their findings and engage in discussions about the future of tardigrade research. The main point of contention among researchers is the use of DNA analysis in studying tardigrades, with some arguing for the need to switch to integrative taxonomy and others believing that both approaches are valid. The symposium also recognized outstanding young scientists and included the presentation of a bell and distribution of tardigrade-themed souvenirs. The proceedings of the symposium cover a wide range of topics, including DNA analysis, taxonomy, ecology, morphology, and physiology, providing valuable insights into the biology and ecology of tardigrades and highlighting the need for further research in this field. [Extracted from the article]

Professor Barbara Węglarska, a renowned Polish scientist, made significant contributions to the fields of tardigrade physiology, morphology, taxonomy, and faunistics. Despite her education being interrupted by World War II, she later earned her M.Sc. and Ph.D. degrees. Throughout her career, she published numerous research articles and co-authored a textbook on insect developmental biology. Professor Węglarska organized an international symposium on tardigrades and received several state medals for her contributions to science and higher education in Poland. She passed away in 2020 at the age of 98, leaving behind a scientific legacy of groundbreaking studies on tardigrades and advancements in taxonomy and faunistics. Colleagues remember her passion for research and mentorship. [Extracted from the article]

Purpose: Fournier's gangrene (FG) is a serious, aggressive, and often fatal multi-organism infection that affects the soft tissues of the perineum, rectum, and external genitalia. This study aimed to analyse the treatment's strategies of FG.Materials and Methods: This was a retrospective study of 35 patients with a diagnosis of FG admitted between 2016 and 2021. The diagnosis of FG was established on a clinical basis. Data on patient's age, sex, comorbidities, laboratory results (C-reactive protein (CRP), white blood cell (WBC), hematocrit (HCT), platelets (PLT), sodium, potassium, creatinine, procalcitonin, international normalized ratio (INR), and gangrene culture), extent of resection, antibiotics used, and hospitalisation time were obtained. The extent of resection was assessed on a scale of 1-5.Results: The study group consisted of all men (n=35) aged 24-85 (mean, 58) years. In 13/35 (37%) patients, hyperbaric oxygen therapy (HBOT) combined with negative-pressure wound therapy (NPWT) was used as a treatment for wound healing in Fournier's syndrome (group 1), and in 22/35 (63%) patients, open standard wound care was used (group 2). There were no fatalities in group 1, but four deaths (18%) were noted in group 2. The median extent of resection was 3 in group 1 and 2 in group 2. There was a correlation between the extent of resection and use of HBOT combined with NPWT. The hospitalisation time was much shorter in group 2 (mean, 23 days) than in group 1 (mean, 26 days).Conclusion: HBOT and NPWT (group 1) showed advanced wound healing with a high efficiency rate. The longer median hospitalisation time in this group may be related to the severity of injury. [ABSTRACT FROM AUTHOR]

The document titled "15th International Symposium on Tardigrada – Section II: Ecology, Life Histories & Behaviour" is a journal article published in the Zoological Journal of the Linnean Society. The article includes an illustration depicting various species of tardigrades in different ecosystems, engaging in behaviors such as mating and hunting. The authors, Łukasz Michalczyk and Kamil Janelt, are affiliated with the Department of Invertebrate Evolution at the Jagiellonian University in Poland. The authors declare no conflict of interest. [Extracted from the article]

The document titled "15th International Symposium on Tardigrada – Section IV: Physiology, Omics, Cryptobiosis & Astrobiology" features an illustration accompanying a talk session on the mentioned topics. The image depicts a tardigrade in an astronaut suit, floating in outer space while holding onto a strand of DNA connected to a space rocket. The concept and design of the image were done by Ł.M. & K.J., with artwork by K.J. & ŁM. The authors of the document, Kamil Janelt and Łukasz Michalczyk, declare no conflict of interest and are affiliated with the Department of Invertebrate Evolution at the Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Kraków, Poland. [Extracted from the article]

The document is an illustration from the Zoological Journal of the Linnean Society, accompanying a talk session on the morphology, anatomy, reproduction, and development of tardigrades. The image depicts a curled eutardigrade embryo inside an ornamented egg, surrounded by a macrobiotid spermatozoon. The authors of the document, Kamil Janelt and Łukasz Michalczyk, are affiliated with the Department of Invertebrate Evolution at the Jagiellonian University in Poland. The image can only be reproduced with written permission from the corresponding author, for non-commercial purposes, and with the full citation provided. [Extracted from the article]

The document titled "15th International Symposium on Tardigrada – Section I: Biodiversity, Taxonomy, Biogeography, Phylogeny & Evolution" discusses the topic of tardigrades, also known as water bears. The document includes an illustration of major tardigrade lineages climbing a phylogenetic tree, representing our current understanding of tardigrade phylogeny. The authors, Łukasz Michalczyk and Kamil Janelt, declare no conflict of interest. The document is authored by researchers from the Department of Invertebrate Evolution at the Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Kraków, Poland. [Extracted from the article]

One of the well-documented behavioral changes that occur with advancing age is a decline in executive functioning, for example, attentional control. Age-related executive deficits are said to be associated with a deterioration of the frontal lobes. Neurofeedback is a training method which aims at acquiring self-control over certain brain activity patterns. It is considered as an effective approach to help improve attentional and self-management capabilities. However, studies evaluating the efficacy of neurofeedback training to boost executive functioning in an elderly population are still relatively rare and controversial. The aim of our study was to contribute to the assessment of the efficacy of neurofeedback as a method for enhancing executive functioning in the elderly. We provided a group of seniors with beta up-training (12–22 Hz), consisting of 20 sessions (30 minutes each), on the Cz site and tested its possible beneficiary influence on attentional control assessed by means of the Stroop and Simon tasks. The analysis of the subjects' mean reaction times during consecutive tasks in the test and the retest, after implementation of neurofeedback training, showed a significant improvement. In contrast, the difference in reaction times between the test and the retest in the control group who had not been submitted to neurofeedback training was not significant. [ABSTRACT FROM AUTHOR]

The Malay Archipelago comprises thousands of islands that house a variety of biomes, from tropical rainforests of Borneo, Sumatra and Celebes to the Lesser Sundas deciduous forests. In this paper, we present an extensive genetic and morphological dataset for the genus Kristenseniscus, demonstrating the presence of the walteri complex that contains several pseudocryptic species. One of them, Kristenseniscus exanthema sp. nov., is described from Ambon and Seram (the Moluccas). First genetic data are released for two potentially pantropical Echiniscus species: E. africanus Murray, 1907 and E. pusae Marcus, 1928. Furthermore, Echiniscus minutus sp. nov. (Sulawesi Tengah), exhibiting trunk spines and contrasting dorsal sculpturing that comprise both pores and epicuticular granules, is found to constitute a separate evolutionary lineage within the Echiniscus spinulosus morphogroup (epicuticular granules are typically absent in the spinulosus group). Based on the phylogenetic reconstructions involving ca. 80 spp. of echiniscids representing the Echiniscus evolutionary line, we hypothesise that the tropical and subtropical regions served as the main radiation zone for this heterotardigrade clade. Finally, Pseudechiniscus (Meridioniscus) celebesiensis sp. nov. (Sulawesi Tengah) is a characteristic species with an apomorphic lack of claw spurs and intricate dorsal cuticular sculpturing. Our findings suggest that the tropical areas of the globe harbour a phylogenetically important but yet mostly uncovered portion of Earth’s tardigrade diversity. [ABSTRACT FROM AUTHOR]

Endogenous attention can be allocated in parallel to at least two saccade target locations of a planned sequence, but attentional resources are larger in the location of the first than the second saccade. The meridian effect that is observed in endogenous attention can be explained by eye programming, but it is not known how eye‐movement preparation and eye programming can together affect endogenous attention during sequential saccades. We used a double‐task paradigm to investigate this issue. In two experiments, we confirmed the relation between the preparation of sequential saccades and attentional selection and also showed that eye programming could eliminate deterioration of attentional resources in the second saccade location. The finding of the meridian effect in both the saccadic task and the target discrimination task additionally indicates the important role of eye programming in endogenous attention. The results were discussed in terms of the Premotor Theory of Attention. [ABSTRACT FROM AUTHOR]

Endogenous attention can be allocated in parallel to at least two saccade target locations of a planned sequence, but attentional resources are larger in the location of the first than the second saccade. The meridian effect that is observed in endogenous attention can be explained by eye programming, but it is not known how eye‐movement preparation and eye programming can together affect endogenous attention during sequential saccades. We used a double‐task paradigm to investigate this issue. In two experiments, we confirmed the relation between the preparation of sequential saccades and attentional selection and also showed that eye programming could eliminate deterioration of attentional resources in the second saccade location. The finding of the meridian effect in both the saccadic task and the target discrimination task additionally indicates the important role of eye programming in endogenous attention. The results were discussed in terms of the Premotor Theory of Attention. [ABSTRACT FROM AUTHOR]

The family Hypsibiidae comprises four subfamilies, among which Itaquasconinae are the most abundant in genera. Although being morphologically diverse and cosmopolitan, itaquasconins are scarcely reported and their taxonomy is entangled. Here, we present a phylogeny based on three DNA markers and morphological clues obtained from a detailed scanning electron microscopy analysis of bucco‐pharyngeal apparatuses of 25 species representing seven genera. Our study revealed that (a) the polyphyletic Adropion consists of at least three evolutionary lineages, with Guidettion gen. nov. being the sister group of all remaining itaquasconins; (b) stylet supports were independently lost in Astatumen and Insulobius gen. nov.; (c) pharyngeal tube annulation can be divided into two general types, simple and complex, and is stable at the genus level, but being homoplasious (similarly to the apophyses for the insertion of stylet muscles and the shape of the claw bases), it is not useful in inferring phyletic relationships within the subfamily; and (d) Astatumen and Platicrista contain numerous similar species, challenging the current taxonomic classification; moreover, (e) three new taxa are proposed to accommodate the newly recognised lineages: Guidettion gen. nov. (the former Adropion prorsirostre group), Insulobius gen. nov. (for a new Malayan species with a mixture of Astatumen and Itaquascon traits), and Raribius gen. nov. (former Itaquascon spp. with an elongated and narrowed pharyngeal tube terminating with a spherical pharynx). The simple type of annulation is synapomorphic to Hypsibiidae, with single reversals to the uniform buccal tube in Parascon (Itaquasconinae) and in Hypsibiinae. The pharyngeal tube evolved convergently several times, and is of different character in classes Heterotardigrada and Eutardigrada. [ABSTRACT FROM AUTHOR]

Australian fauna is widely recognised for its high levels of endemism, and tardigrade fauna does not seem to be an exception in this respect. The richness of xerothermic habitats in Australia, often occupied by heterotardigrade family Echiniscidae, entails high abundance and uniqueness of echiniscid assemblages. A new gonochoristic/dioecious echiniscid species was found in large numbers in samples from Western Australia. Echiniscus siticulosussp. nov., characterised by dominant large cuticular pores in the dorsal sculpture and appendages in the form of spines, represents the spinulosus group but can be distinguished from the known members of this species complex by a unique combination of traits: peculiar faceting of the caudal plate formed by ridge-shaped epicuticular extensions and pore morphology. An amended phenotypic diagnosis of Echiniscus spiniger Richters 1904, the species morphologically most similar to the new species, is also presented. [ABSTRACT FROM AUTHOR]

The 14th International Symposium on Tardigrada took place in Copenhagen, Denmark from 30 July to 3 August 2018. Approximately 140 participants, representing 28 countries from five continents attended the meeting, and there were 58 talks and 74 posters of which 20 were selected for the Symposium Proceedings published in this special issue. The studies span phylogenomics, systematics, anatomy, morphology, reproductive biology, cryobiology, ecology, diet, microbial interactions and biogeography, taking the next step forward in broadening and deepening our understanding of tardigrade biology. [ABSTRACT FROM AUTHOR]

The largest apochelan genus, Milnesium , is increasingly gaining attention. However, our knowledge on the phylogeny of Milnesiidae is strongly limited. In fact, so far, apochelan species usually served only as outgroups in phylogenetic analyses of other tardigrade groups. Thus, the goal of this study was to reconstruct the first multilocus molecular phylogeny of Milnesium and test several hypotheses on the evolution and dispersion of species in the genus by mapping taxonomically important morphological traits, reproductive mode and geographic distribution onto the phylogenetic tree. The phylogeny was inferred from four DNA markers (nuclear 18S rRNA, 28S rRNA, ITS2 and mitochondrial COI) and for 34 populations representing 25 species collected across the globe. Phylogenetic analysis revealed distinct molecular lineages within the genus, but rather than by morphological characters, species clustered by zoogeographic zones. In fact, no obvious patterns of phenotypic traits or reproductive mode were observed, which may indicate high levels of convergent evolution in morphology throughout the genus. The lack of congruence between morphology and phylogeny did not allow splitting this largest apochelan genus into separate taxonomic units such as genera or subgenera. On the other hand, the correlation between phylogeny and geography may suggest limited dispersal of at least some Milnesium species. [ABSTRACT FROM AUTHOR]

The Premotor Theory of Attention (PToA) is a prominent, albeit controversial, modern experimental account of attentional processes. According to the PToA, motor preparation is both necessary and sufficient for spatial attention. Explaining the cognitive process of attention in terms of sensori-motor machinery can be considered as embedded in the idea of embodied cognition. The vocabulary adopted by the PToA seems to bear a particular resemblance to Merleau-Ponty's phenomenological notion of pre-reflective intentionality. He articulates it by means of directness towards the lived world, which is constituted in the spatial motility of the body-subject. In this epistemological state of affairs, we come up with two leading questions: (a) can the main tenets of PToA be essentially reconstructed in terms of the notion of pre-reflective intentionality and since the bodily motility is meant by the French phenomenologist to be at the root of all forms of intentionality, (b) can the PToA be expanded to account for all kinds of attention? In conclusion, we advocate a positive answer for the former question and point to serious doubts as to why it can rather not be retained regarding the latter. [ABSTRACT FROM AUTHOR]

In the Posner cueing paradigm, the early attentional capture and subsequent inhibition of return (IOR) of attention to the same location, although they are microscale phenomena measured in milliseconds, seem to encapsulate the interaction between two fundamental dimensions of behavior - engaging in and sustaining activity versus withdrawing from and inhibiting activity. In the field of differential psychology, the dynamics of reciprocal relations between these behavioral dimensions have been thought to be determined by central nervous system properties that constitute an individual's temperament. Yet the research on any differential effects of temperament on visuospatial orienting is rather sparse and has produced ambiguous results. Here, we used saccadic responses to measure whether individual differences in reactivity as a temperamental trait might affect orienting of visuospatial attention on discrimination cueing tasks. Our results suggested that, in individuals with lower reactivity, attentional capture took place at a short stimulus onset asynchrony (SOA), producing a facilitatory cueing effect, which was not the case in those who were higher in reactivity. We explain and discuss these results with the Regulative Theory of Temperament. [ABSTRACT FROM AUTHOR]

• The pupillary light response reflects inhibition of return (IOR). • Pupillary IOR decrease after fixation offset. • Pupillary IOR is related to the eye movement preparation. • Decrease of the IOR after fixation offset to support the Premotor Theory of Attention. Inhibition of return (IOR) is reflected as a slower manual or saccadic response to a cued rather than an uncued target (manual IOR and saccadic IOR, respectively), and as a pupillary dilation when a bright, relative to a dark side of a display is cued (pupillary IOR). The aim of this study was to investigate the relation between an IOR and oculomotor system. According to the predominant view, only the saccadic IOR is strictly related to the visuomotor process, and the manual and pupillary IORs depend on non-motor factors (e.g., short-term visual depression). Alternatively, the after-effect of the covert-orienting hypothesis postulates that IOR is strictly related to the oculomotor system. As fixation offset affects oculomotor processes, this study investigated whether fixation offset also affects pupillary and manual IORs. The results show that fixation offset decreased IOR in pupillary but not manual responses, and provides support for the hypothesis that at least the pupillary IOR is tightly linked to eye movement preparation. [ABSTRACT FROM AUTHOR]

Inhibition of return (IOR) is the effect of slower responses to validly than invalidly cued targets. The discovery of IOR raised controversy as to whether it has two "flavors", i.e., attentional/perceptual and motoric, or whether it is a homogeneous visual-motor phenomenon that should be understood in terms of the preparation of different effectors (mainly eye movement). Since manipulation of fixation offset (0 and 200 ms gap) is believed to affect the latency of saccades, we measured its influence on saccadic and manual IOR with a simple keypress response when eye movements were forbidden. In the two experiments which we carried out, the fixation offset decreased IOR in both the saccadic and the manual conditions. The results suggest the limitations of the attentional hypothesis, which assumes that manual IOR is independent of the motoric component; they are also in line with the tenets of the oculomotor hypothesis of IOR. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Numerous evolutionary lineages representing an armoured, limno-terrestrial family Echiniscidae are restricted to high mountainous or polar localities, exhibiting clear cold stenothermic preferences. One such group is the genus Claxtonia , with its type species Claxtonia wendti , originally described from Svalbard and later on reported globally. In this paper, we re-describe this taxon by establishing the neotype from Spitsbergen. We sequenced five genetic markers (18S rRNA, 28S rRNA, ITS-1, ITS-2, and COI) for multiple populations of Claxtonia , including C. mauccii , C. molluscorum , C. wendti , and several potentially new species, collected in the Alps, Andes, Carpathians, Scotland, Iceland, Southern Appalachians, Spitsbergen, Scandinavian Peninsula, Borneo, and the West Indies. The relationships between these species are elucidated thanks to the phylogenetic reconstructions based on nuclear loci. Various Claxtonia species frequently co-occur in mosses and lichens, which hampers delineating their probable geographic ranges. All historical records of C. wendti are questioned in the light of our revision. Delineation of new species within the genus is nipped in the bud due to numerous problems with original species descriptions, unknown intraspecific (including ontogenetic) variability, and the lack of DNA barcodes. Finally, it is hypothesized that Claxtonia potentially comprises two lineages: a cold-stenothermic one and a thermophilic subtropical–tropical one. [ABSTRACT FROM AUTHOR]

Most cases of alternative reproductive tactics (ARTs) are thought to represent conditional strategies, whereby high-status males express highly competitive phenotypes, whereas males below a certain status threshold resort to sneaky tactics. The underlying evolutionarily stable strategy (ESS) model assumes that males of high competitive ability achieve higher fitness when expressing the territorial phenotype, whereas the less competitive males are more fit as sneakers, caused by fitness functions for the ARTs having different slopes and intersecting at a threshold value of competitive ability. The model, however, is notoriously difficult to test as it requires access to low-status territorials and high-status sneakers, that rarely occur in nature. Here, we test the conditional ESS in the androdimorphic acarid mite Sancassania berlesei, where large males tend to develop into an armoured, aggressive 'fighter' morph, while small males become unarmoured, non-aggressive 'scramblers'. In addition to body size, male morph is affected by pheromones produced by big populations, with fighters being suppressed in dense colonies. By manipulating pheromone concentration, we obtained high-status scramblers and low-status fighters. We also estimated status- and size-dependent fitness functions for male morphs across a range of population sizes. Fighters had the highest fitness in small populations and their fitness declined with increasing density, whereas the reverse was true for scramblers, providing support for condition-dependent ESS with respect to demography. However, whereas male fitness increased with body size, the fitness functions did not differ significantly between morphs. Thus, although we found evidence for the intersection of morph fitness functions with respect to demography, we did not find such an intersection in relation to male body size. Our results highlight how demography can exert selection pressures shaping the evolution of the conditional strategy in species with ARTs. [ABSTRACT FROM AUTHOR]

The effect of slower responses to validly than invalidly cued targets is known as inhibition of return (IOR). Opposing accounts of IOR have been proposed: one postulates a singular phenomenon explained by oculomotor mechanisms alone, while the other, more diverse account postulates both perceptual-cognitive and motor factors. In our research we considered the relation between motor programming and IOR. In an extended replication of an earlier study, using an eye abduction technique we restricted eye movement in the temporal half-space; this resulted in IOR attenuation in that area, compared to the unrestricted, nasal part of the visual field. Our results contradict the earlier result and demonstrate that IOR does depend on preparation of eye movement, as predicted by the oculomotor priming hypothesis. [ABSTRACT FROM AUTHOR]

Neurophenomenology is intended to be a remedy for the hard problem of consciousness (Varela, 1996). There are, however, serious doubts as to whether it addresses the hard problem per se or is merely meant as a way for a more practical marriage between the domain of experience and neuroscience. If the latter is true, closing the gap would, at best, result in developing better models of phenomenality and better models of neuronal activity (Bayne, 2004). The technology of neurofeedback (NFB), which helps subjects to selfregulate their own neural activation, is considered as a pragmatic tool to overcome some of the obstacles being faced by neurophenomenology (Bagdasatyan and Le Van Quyen, 2013). In this epistemological and methodological context, our aim in this paper is to discuss whether the neurofeedback paradigm can help to close the explanatory gap. In the face o f doubts concerning the issue we also propose analysing NFB in terms of personal neuroscience as another perspective for linking mental and neural events. [ABSTRACT FROM AUTHOR]

Rensch's rule proposes a universal allometric scaling phenomenon across species where sexual size dimorphism (SSD) has evolved: in taxa with male-biased dimorphism, degree of SSD should increase with overall body size, and in taxa with female-biased dimorphism, degree of SSD should decrease with increasing average body size. Rensch's rule appears to hold widely across taxa where SSD is male-biased, but not consistently when SSD is female-biased. Furthermore, studies addressing this question within species are rare, so it remains unclear whether this rule applies at the intraspecific level. We assess body size and SSD within Tribolium castaneum (Herbst), a species where females are larger than males, using 21 populations derived from separate locations across the world, and maintained in isolated laboratory culture for at least 20 years. Body size, and hence SSD patterns, are highly susceptible to variations in temperature, diet quality and other environmental factors. Crucially, here we nullify interference of such confounds as all populations were maintained under identical conditions (similar densities, standard diet and exposed to identical temperature, relative humidity and photoperiod). We measured thirty beetles of each sex for all populations, and found body size variation across populations, and (as expected) female-biased SSD in all populations. We test whether Rensch's rule holds for our populations, but find isometry, i.e. no allometry for SSD. Our results thus show that Rensch's rule does not hold across populations within this species. Our intraspecific test matches previous interspecific studies showing that Rensch's rule fails in species with female-biased SSD. [ABSTRACT FROM AUTHOR]

Because of divergent selection acting on males and females arising from different life-history strategies, polyandry can be expected to promote sexual dimorphism of investment into immune function. In previous work we have established the existence of such divergence within populations where males and females are exposed to varying degrees of polyandry. We here test whether the removal of sexual selection via enforced monogamy generates males and females that have similar levels of investment in immune function. To test this prediction experimentally, we measured differences between the sexes in a key immune measurement (phenoloxidase (PO) activity) and resistance to the microsporidian Paranosema whitei in Tribolium castaneum lines that evolved under monogamous (sexual selection absent) vs polyandrous (sexual selection present) mating systems. At generation 49, all selected lines were simultaneously assessed for PO activity and resistance to their natural parasite P. whitei after two generations of relaxed selection. We found that the polyandrous regime was associated with a clear dimorphism in immune function: females had significantly higher PO activities than males in these lines. In contrast, there was no such difference between the sexes in the lines evolving under the monogamous regime. Survival in the infection experiment did not differ between mating systems or sexes. Removing sexual selection via enforced monogamy thus seems to erase intersexual differences in immunity investment. We suggest that higher PO activities in females that have evolved under sexual selection might be driven by the increased risk of infections and/or injuries associated with exposure to multiple males. [ABSTRACT FROM AUTHOR]

Reproduction through sex carries substantial costs, mainly because only half of sexual adults produce offspring. It has been theorized that these costs could be countered if sex allows sexual selection to clear the universal fitness constraint of mutation load. Under sexual selection, competition between (usually) males and mate choice by (usually) females create important intraspecific filters for reproductive success, so that only a subset of males gains paternity. If reproductive success under sexual selection is dependent on individual condition, which is contingent to mutation load, then sexually selected filtering through 'genic capture' could offset the costs of sex because it provides genetic benefits to populations. Here we test this theory experimentally by comparing whether populations with histories of strong versus weak sexual selection purge mutation load and resist extinction differently. After evolving replicate populations of the flour beetle Tribolium castaneum for 6 to 7 years under conditions that differed solely in the strengths of sexual selection, we revealed mutation load using inbreeding. Lineages from populations that had previously experienced strong sexual selection were resilient to extinction and maintained fitness under inbreeding, with some families continuing to survive after 20 generations of sib × sib mating. By contrast, lineages derived from populations that experienced weak or non-existent sexual selection showed rapid fitness declines under inbreeding, and all were extinct after generation 10. Multiple mutations across the genome with individually small effects can be difficult to clear, yet sum to a significant fitness load; our findings reveal that sexual selection reduces this load, improving population viability in the face of genetic stress. [ABSTRACT FROM AUTHOR]

Reaction times to targets presented at previously stimulated locations are longer after some time (approx. 300 ms) than to targets presented in new locations. This effect is widely known as Inhibition of Return (IOR). It is typically explained in terms of an inhibitory bias against returning attention to places previously attended to and thus promoting attentional activity elsewhere. Regardless of its attentional character, IOR seems to encapsulate the interaction between two fundamental dimensions of temperament: engaging in versus inhibition and withdrawal from activity. Approaching IOR in this perspective, the question has arisen as to whether individual differences in reactivity as a temperamental trait express themselves in the time course and magnitude of this effect. 90 subjects (30 low, 30 medium and 30 highly reactive individuals) participated in the study. To the best of our knowledge, there are no other studies of individual differences in these parameters of IOR that use saccadic responses to measure its effect on behavior. The results show that in individuals who are higher in terms of their reactivity, IOR starts earlier and continues at the following SOAs but its magnitude is smaller than in less reactive individuals. The results are explained and discussed in light of the Regulative Theory of Temperament. This is the final version of the Abstract which has been accepted in the revised manuscript. • In the study, we used saccadic responses to measure temperamental differences in IOR. • Individual differences in emotional reactivity were discovered in the time course and magnitude of IOR. • In high vs. low reactive individuals, IOR starts earlier but its magnitude is smaller. • Temperament can influence microscale processes and effects evinced in saccadic movements. [ABSTRACT FROM AUTHOR]

Microbiota are considered significant in the biology of tardigrades, yet their diversity and distribution remain largely unexplored. This is partly due to the methodological challenges associated with studying the microbiota of small organisms that inhabit microbe‐rich environments. In our study, we characterized the microbiota of 31 species of cultured tardigrades using 16S rRNA amplicon sequencing. We employed various sample preparation strategies and multiple types of controls and estimated the number of microbes in samples using synthetic DNA spike‐ins. We also reanalysed data from previous tardigrade microbiome studies. Our findings suggest that the microbial communities of cultured tardigrades are predominantly composed of bacterial genotypes originating from food, medium, or reagents. Despite numerous experiments, we found it challenging to identify strains that were enriched in certain tardigrades, which would have indicated likely symbiotic associations. Putative tardigrade‐associated microbes rarely constituted more than 20% of the datasets, although some matched symbionts identified in other studies. We also uncovered serious contamination issues in previous tardigrade microbiome studies, casting doubt on some of their conclusions. We concluded that tardigrades are not universally dependent on specialized microbes. Our work underscores the need for rigorous safeguards in studies of the microbiota of microscopic organisms and serves as a cautionary tale for studies involving samples with low microbiome abundance. [ABSTRACT FROM AUTHOR]

The phylum Tardigrada comprises ~ 1400 described species that inhabit a wide range of ecosystems throughout the globe. Tardigrades are generally considered taxonomically challenging due to a strongly limited number of taxonomically informative morphological traits and microscopic size. Of all tardigrade groups, the taxonomy of Milnesium Doyère, 1840 is particularly difficult because in comparison with most other eutardigrades, the genus lacks the taxonomically informative egg shell ornamentation and/or placoids in the muscle pharynx. Therefore, any new morphological traits that could be used in species delineation and identification are priceless. In this contribution, we review and evaluate taxonomic value of the dorsal cuticle morphology. Specifically, by means of experimental taxonomy, we demonstrate the first extreme case of ontogenetic variability in dorsal epicuticle sculpturing using a new species from Portugal, Milnesium decorumsp. nov. Furthermore, we verify the existence of dorsal gibbosities in Milnesium reticulatum Pilato, Binda, Lisi, 2002, the only species of the genus allegedly exhibiting these structures. Finally, we provide a diagnostic key to the Milnesium granulatum morphogroup. [ABSTRACT FROM AUTHOR]

Tardigrade taxonomy is most often hindered by prevalent outdated species descriptions, lack of integrative redescriptions, scarce genetic information, and fragmentary sampling. Here, we diagnose the problems obscuring phylogenetic inference and the taxonomy of the cosmopolitan family Ramazzottiidae. We carried out the most extensive phylogenetic analysis of this family to date, with a considerable influx of new genetic data from poorly sampled regions of the world. We found two new distinct evolutionary lineages defined by distinct morphological traits (dorsal cuticular sculpturing and/or body shape), characterized by restricted geographic distributions, and we delineated them as new species complexes: the Neotropical Ramazzottius baumanni complex and the Afro-Oriental Ramazzottius szeptyckii complex. Nevertheless, we could not confidently ascertain the taxonomic status of both complexes due to: (i) the current state of the ramazzottiid taxonomy, with outdated and/or imprecise species descriptions with heterogeneous terminology and, in many cases, without accounting for intraspecific variation; (ii) the missing genetic information for key taxa; and (iii) the possible lack of monophyly of Cryoconicus and Ramazzottius as suggested by our results. In addition to diagnosing the problems of ramazzottiid phylogeny and systematics, we also propose possible solutions that could accelerate the progress in our understanding of the evolution of this group. [ABSTRACT FROM AUTHOR]

The order Apochela, the only exclusively carnivorous tardigrade lineage, comprises four genera, of which Milnesium contains multiple species and is common and cosmopolitan, whereas the remaining genera (Bergtrollus , Limmenius and Milnesioides) are monotypic, rare and have restricted geographical distributions. More importantly, although there are ample genetic data for numerous Milnesium species, no other apochelan genus has been sequenced so far, which limits our understanding of milnesiid evolution. In this contribution, we analysed two populations of Milnesioides from the south coast of Western Australia. The obtained molecular phylogenetic tree clearly indicated Milnesioides as a sister lineage to all remaining Milnesium species, supporting the validity of the genus. Moreover, the sister relationship of Milnesioides and Milnesium lends support to the Gondwanan origin of the order Apochela. Phenotypic differences between the type population of Milnesioides exsertum from New South Wales and the populations from Western Australia analysed in this study suggest that the latter represent a new species. The new data and morphological differences between populations reported in the original description of Milnesioides strongly suggest that the genus is not monotypic. [ABSTRACT FROM AUTHOR]

Earth's biodiversity is undergoing mass extinction due to anthropogenic compounding of environmental, demographic and genetic stresses. These different stresses can trap populations within a reinforcing feedback loop known as the extinction vortex, in which synergistic pressures build upon one another through time, driving down population viability. Sexual selection, the widespread evolutionary force arising from competition, choice and reproductive variance within animal mating patterns could have vital consequences for population viability and the extinction vortex: (a) if sexual selection reinforces natural selection to fix 'good genes' and purge 'bad genes', then mating patterns encouraging competition and choice may help protect populations from extinction; (b) by contrast, if mating patterns create load through evolutionary or ecological conflict, then population viability could be further reduced by sexual selection. We test between these opposing theories using replicate populations of the model insect Tribolium castaneum exposed to over 10 years of experimental evolution under monogamous versus polyandrous mating patterns. After a 95‐generation history of divergence in sexual selection, we compared fitness and extinction of monogamous versus polyandrous populations through an experimental extinction vortex comprising 15 generations of cycling environmental and genetic stresses. Results showed that lineages from monogamous evolutionary backgrounds, with limited opportunities for sexual selection, showed rapid declines in fitness and complete extinction through the vortex. By contrast, fitness of populations from the history of polyandry, with stronger opportunities for sexual selection, declined slowly, with 60% of populations surviving by the study end. The three vortex stresses of (a) nutritional deprivation, (b) thermal stress and (c) genetic bottlenecking had similar impacts on fitness declines and extinction risk, with an overall sigmoid decline in survival through time. We therefore reveal sexual selection as an important force behind lineages facing extinction threats, identifying the relevance of natural mating patterns for conservation management. [ABSTRACT FROM AUTHOR]

Identification of tardigrade species is still reliant mostly on morphological and morphometric traits. Given that the number of taxonomically significant traits available in the genus Milnesium is exceptionally low, ontogenetic variability may provide additional methods for species delineation. However, it is notoriously difficult to establish whether both immature and sexually mature instars are present in examined populations. Here, we developed a simple analytical morphometric method that helps in testing whether both immature and mature life stages are present in a given set of individuals. In order to achieve this, we analysed 21 populations representing 11 Milnesium species, with developmental tracking data available for four species. Using cluster analysis, individuals were assigned accurately to three groups of instars: hatchlings, juveniles and adults (third instar onwards). Our analyses revealed that the most useful character in life-stage classification is buccal tube length. The method of classification of instars presented herein could be used as a simple tool for identification of the number of life stages present in a population. Finally, using our algorithm, we analysed morphometric datasets underlying the descriptions and redescriptions of all known Milnesium species to date and concluded that the majority of them did not include all three life-stage groups. [ABSTRACT FROM AUTHOR]

Ranges of tardigrade intraspecific and interspecific variability are not precisely defined, both in terms of morphology and genetics, rendering descriptions of new taxa a cumbersome task. This contribution enhances the morphological and molecular dataset available for the heterotardigrade genus Viridiscus by supplying new information on Southern Nearctic populations of V.perviridis, V.viridianus, and a new species from Tennessee. We demonstrate that, putting aside already well-documented cases of significant variability in chaetotaxy, the dorsal plate sculpturing and other useful diagnostic characters, such as morphology of clavae and pedal platelets, may also be more phenotypically plastic characters at the species level than previously assumed. As a result of our integrative analyses, V.viridianus is redescribed, V.celatus sp. nov. described, and V.clavispinosus designated as nomeninquirendum, and its junior synonymy with regard to V.viridianus suggested. Morphs of three Viridiscus species (V.perviridis, V.viridianus, and V.viridissimus) are depicted, and the implications for general echiniscid taxonomy are drawn. We emphasise that taxonomic conclusions reached solely through morphological or molecular analyses lead to a distorted view on tardigrade α-diversity. [ABSTRACT FROM AUTHOR]

Many species of microscopic invertebrates, such as tardigrades or rotifers, have been traditionally regarded as cosmopolitan. This conviction was based on classical taxonomic observations of very similar phenotypes across the globe and hypothetical abilities of micrometazoans for large-scale dispersal with air and water currents. However, several recent studies showed that micrometazoan species may have restricted geographic ranges, suggesting that microscopic size is not the only determinant of dispersal. Here, we describe the first Australasian record of Echiniscus testudo, a heterotardigrade originally described from the Holarctic. Morphological and genetic analyses gave congruent conclusions and confirmed that European and New Zealand populations represent a single species. Importantly, however, without broader sampling in primeval localities, it is not possible to test whether the New Zealand record of E. testudo is a result of natural dispersal or whether the species was brought to Australasia by humans. [ABSTRACT FROM AUTHOR]

Abstract: Despite limitations on offspring production, almost all multicellular species use sex to reproduce. Sex gives rise to sexual selection, a widespread force operating through competition and choice within reproduction, however, it remains unclear whether sexual selection is beneficial for total lineage fitness, or if it acts as a constraint. Sexual selection could be a positive force because of selection on improved individual condition and purging of mutation load, summing into lineages with superior fitness. On the other hand, sexual selection could negate potential net fitness through the actions of sexual conflict, or because of tensions between investment in sexually selected and naturally selected traits. Here, we explore these ideas using a multigenerational invasion challenge to measure consequences of sexual selection for the overall net fitness of a lineage. After applying experimental evolution under strong versus weak regimes of sexual selection for 77 generations with the flour beetle Tribolium castaneum, we measured the overall ability of introductions from either regime to invade into conspecific competitor populations across eight generations. Results showed that populations from stronger sexual selection backgrounds had superior net fitness, invading more rapidly and completely than counterparts from weak sexual selection backgrounds. Despite comprising only 10% of each population at the start of the invasion experiment, colonizations from strong sexual selection histories eventually achieved near‐total introgression, almost completely eliminating the original competitor genotype. Population genetic simulations using the design and parameters of our experiment indicate that this invasion superiority could be explained if strong sexual selection had improved both juvenile and adult fitness, in both sexes. Using a combination of empirical and modeling approaches, our findings therefore reveal positive and wide‐reaching impacts of sexual selection for net population fitness when facing the broad challenge of invading competitor populations across multiple generations. [ABSTRACT FROM AUTHOR]

Background: Urolithiasis is one of the most common diseases of the urinary system, the incidence of which is assumed to be up to 100,000 cases per million (10% of the population). The cause of it is dysregulation of renal urine excretion. Acromegaly is a very rare endocrine disorder that causes a somatotropic pituitary adenoma producing higher amounts of growth hormone. It occurs approximately in 80 cases per million (about 0.008% of the population). One of the acromegaly complications may be urolithiasis. Methods: Clinical and laboratory results of 2289 patients hospitalized for nephrolithiasis in the highest reference hospital were retrospectively analyzed, distinguishing a subgroup of patients with acromegaly. Statistical analysis was performed to compare the prevalence of the disease in the analyzed subgroup with the epidemiological results available in up-to-date literature. Results: The distribution of nephrolithiasis treatment was definitely in favor of non-invasive and minimally invasive treatment. The methods used were as follows: ESWL (61.82%), USRL (30.62%), RIRS (4.15%), PCNL (3.1%), and pyelolithotomy (0.31%). Such a distribution limited the potential complications of the procedures while maintaining the high effectiveness of the treatment. Among two thousand two hundred and eighty-nine patients with urolithiasis, two were diagnosed with acromegaly before the nephrological and urological treatment, and seven were diagnosed de novo. Patients with acromegaly required a higher percentage of open surgeries (including nephrectomy) and also had a higher rate of kidney stones recurrence. The concentration of IGF-1 in patients with newly diagnosed acromegaly was similar to those treated with somatostatin analogs (SSA) due to incomplete transsphenoidal pituitary surgery. Conclusions: In the population of patients with urolithiasis requiring hospitalization and interventional treatment compared to the general population, the prevalence of acromegaly was almost 50-fold higher (p = 0.025). Acromegaly itself increases the risk of urolithiasis. [ABSTRACT FROM AUTHOR]

Tardigrade research in Japan dates back over 100 years, and to date, 167 species of this ecdysozoan phylum have been reported from the country. Of these species, the Macrobiotus hufelandi complex has been represented only by the nominal taxon of this group, Macrobiotus hufelandi. In this article, a new species of the hufelandi group from Japan, Macrobiotus shonaicus sp. nov., is described using integrative taxonomy. In addition to the detailed morphological and morphometric data, obtained using phase contrast light microscopy (PCM) and scanning electron microscopy (SEM), we provide DNA sequences of four molecular markers (both nuclear and mitochondrial). The new species belongs to the persimilis subgroup and is most similar to M. anemone from USA, M. naskreckii from Mozambique, and M. patagonicus from Argentina, but it can be easily distinguished from these species by the presence of thin flexible filaments on terminal discs of the egg process. By the latter character, the new species is most similar to M. paulinae and M. polypiformis, but it can be easily distinguished from them by having a solid egg surface between egg processes (i.e., without pores or reticulum). A phylogenetic analysis of available DNA sequences of the COI marker for the hufelandi group revealed that the new species clusters with the two other species that exhibit filaments on egg process discs (M. paulinae and M. polypiformis) and with two species that have entire egg processes modified into filaments (M. kristenseni and M. scoticus). All five species form a clade distinct from all other sequenced species of the hufelandi group with typical mushroom- or inverted goblet-shaped egg processes, which may suggest that the ancestor of the five species with atypical egg processes had a mutation allowing derivations from the mushroom or inverted chalice-like shape of egg processes. [ABSTRACT FROM AUTHOR]

The recent integrative revision of the family Macrobiotidae demonstrated monophyly of the genus Macrobiotus and its complex, mosaic morphological evolution. Here, we analyse three Macrobiotus populations that exhibit extraordinary claw morphology characterized by elongated primary branches. Two of these populations, from the Arctic, were initially classified as Macrobiotus ariekammensis , but detailed integrative analyses resulted in splitting them into two subspecies: Macrobiotus ariekammensis ariekammensis and Macrobiotus ariekammensis groenlandicus subsp. nov.. The third population was Macrobiotus kirghizicus from Kyrgyzstan. Given the unusual phenotype of the above-mentioned taxa, we tested whether they constitute a distinct lineage in the family Macrobiotidae and could be delineated as a new genus. Although the phylogenetic investigation showed that the three taxa form a monophyletic group, the clade is nested in the genus Macrobiotus. Therefore, despite their morphological distinctiveness, a new genus cannot be established and we group these taxa in the Macrobiotus ariekammensis species complex instead. The complex includes the three above-mentioned taxa and Macrobiotus ramoli , which is included based on morphological characters. Moreover, our results provide evidence for rapid parallel evolution of long claws in macrobiotid tardigrades inhabiting cold and icy environments. Finally, we discuss the validity of the recent suppression of the genus Xerobiotus , which gathers macrobiotids with reduced claws. [ABSTRACT FROM AUTHOR]

The genus Barbaria , recently established to accommodate the former Echiniscus bigranulatus group, is a tardigrade group emblematic for the South American tardigrade fauna. This unappendaged echiniscid lineage is widely recognized for the so-called 'double' sculpturing composed of endocuticular pillars and pseudopores or pores in the dorsal cuticle. The phylogenetic relationships in the genus have so far been completely unknown, but the discovery of two new species (B. paucigranulata sp. nov. and B. weglarskae sp. nov.), together with new genetic data for further six species (B. bigranulata , B. charrua comb. nov. , B. danieli , B. jenningsi , B. madonnae and B. ollantaytamboensis), create an opportunity not only to uncover phyletic relationships, but also to reconstruct morphological evolution in the genus. To achieve this, we sequenced five genetic markers (18S rRNA, 28S rRNA, ITS1, ITS2, COI) for multiple populations of eight species of Barbaria (two-thirds of all known species) collected in Alabama (USA), Argentina and the Antarctic, and we analysed them in tandem with detailed morphological data. Our phylogentic analysis and the reconstruction of evolution of morphological traits suggests that the ancestor of the genus inhabited the Neotropics, and it was morphologically most similar to B. bigranulata. We also analyse literature records of Barbaria and conclude that the genus is most likely limited to the Neotropics, Antarctica and southern parts of the Nearctic. The findings are discussed in the context of the phylogeny of the Echiniscus evolutionary line. [ABSTRACT FROM AUTHOR]

Female sperm storage is ubiquitous in the animal kingdom and it has been shown to be linked to several evolutionary processes, from postcopulatory sexual selection to dispersal. Here we report, for the first time, long‐term sperm storage in females of the tardigrade Macrobiotus polonicus. Females, isolated after a short contact with a male, were able to use the stored sperm for up to 5 weeks (mean of 2 weeks), which translates to a considerable proportion of female post‐mating longevity under controlled laboratory conditions (60% on average). Our study provides the first insights into the duration of sperm storage, an underexplored feature of the reproductive biology of tardigrades. Additionally, we discuss important considerations for reproductive studies on these non‐model animals. [ABSTRACT FROM AUTHOR]

Tardigrades are ubiquitous microfauna that act as consumers and predators in soil food webs. Several studies have suggested that tardigrades have great potential to control nematode populations. However, the regulatory function of tardigrades depends on many factors, including their feeding preferences. Yet, tardigrade feeding preferences remain largely unresolved. Therefore, in our experiment, nine predatory tardigrade species were tested for their preferences for three types of microfauna prey (nematodes, rotifers and tardigrades) under controlled laboratory conditions. We also tested whether tardigrade prey preferences can be predicted by selected functional traits (body length and buccal tube dimensions), because such traits are known to be a powerful tool in determining ecological links between organisms. We observed overall avoidance of tardigrades as prey along with preference for nematode prey. The difference in the total consumed number of the three types of prey were attributable to predator species identity, whereas proportional differences in the three types of prey in the diet were attributable to buccal tube length. Buccal tube width, buccal tube width to length ratio and body length lacked the predictive power for feeding preferences of predatory tardigrades. Our results showed that buccal tube length is more informative of tardigrade prey preference than predator species identity and can be used to predict tardigrade feeding preferences. The knowledge of tardigrade feeding preferences is crucial for understanding the role of tardigrades in soil food web. • Prey preference of predatory tardigrades can be estimated by buccal tube length. • The longer the buccal tube, the higher proportion of tardigrades in the diet. • The longer the buccal tube, the lower proportion of nematodes in the diet. [ABSTRACT FROM AUTHOR]

There are two predominant sources of taxonomically useful morphological variability in the diverse tardigrade family Echiniscidae: the internal structure and surface sculpture of the cuticular plates covering the dorsum (sculpturing) and the arrangement and morphology of the trunk appendages (chaetotaxy). However, since the appendages often exhibit intraspecific variation (they can be reduced or can develop asymmetrically), sculpturing has been considered more stable at the species level and descriptions of new echiniscid species based solely on morphology are still being published. Here, we present a case study in which a detailed analysis of the morphology and multiple genetic markers of several species of the genus Viridiscus shows that cuticular sculpture may also exhibit considerable intraspecific variation and lead to false taxonomic conclusions. In a population collected from the eastern Nearctic, in the type locality of the recently described species V. miraviridis, individuals with transitional morphotypes between those reported for V. viridissimus and V. miraviridis were found. Importantly, all morphotypes within the viridissimus–miraviridis spectrum were grouped in a single monospecific clade according to rapidly evolving markers (ITS-1, ITS-2 and COI). Given the morphological and genetic evidence, we establish V. miraviridis as a junior synonym of V. viridissimus. This study explicitly demonstrates that a lack of DNA data associated with morphological descriptions of new taxa jeopardizes the efforts to unclutter tardigrade systematics. Additionally, V. perviridis and V. viridissimus are reported from Lâm Đồng Province in southern Vietnam, which considerably broadens their known geographic ranges. [ABSTRACT FROM AUTHOR]

There is ample evidence that macroscopic animals form geographic clusters termed as zoogeographic realms, whereas distributions of species of microscopic animals are still poorly understood. The common view has been that micrometazoans, thanks to their putatively excellent dispersal abilities, are subject to the "Everything is everywhere but environment selects" hypothesis (EiE). One of such groups, <1 mm in length, are limnoterrestrial water bears (Tardigrada), which can additionally enter cryptobiosis that should further enhance their potential for long distance dispersion (e.g., by wind). However, an increasing number of studies, including the most recent phylogeny of the eutardigrade genus Milnesium, seem to question the general applicability of the EiE hypothesis to tardigrade species. Nevertheless, all Milnesium phylogenies published to date were based on a limited number of populations, which are likely to falsely suggest limited geographic ranges. Thus, in order to test the EiE hypothesis more confidently, we considerably enlarged the Milnesium data set both taxonomically and geographically, and analysed it in tandem with climate type and reproductive mode. Additionally, we time‐calibrated our phylogeny to align it with major geological events. Our results show that, although cases of long distance dispersal are present, they seem to be rare and mostly ancient. Overall, Milnesium species are restricted to single zoogeographic realms, which suggests that these tardigrades have limited dispersal abilities. Finally, our results also suggest that the breakdown of Gondwana may have influenced the evolutionary history of Milnesium. In conclusion, phylogenetic relationships within the genus seem to be determined mainly by paleogeography. [ABSTRACT FROM AUTHOR]

The cosmopolitan echiniscid genus Hypechiniscus contains exclusively rare species. In this contribution, by combining statistical morphometry and molecular phylogeny, we present qualitative and quantitative aspects of Hypechiniscus diversity, which remained hidden under the two purportedly cosmopolitan species: H. gladiator and H. exarmatus. A neotype is designated for H. gladiator from Creag Meagaidh (Scotland), and an informal re-description is provided for H. exarmatus based on animals from Creag Meagaidh and the Isle of Skye (Inner Hebrides). Subspecies/forms of H. gladiator are suppressed due to the high developmental variability of the cirrus dorsalis. At the same time, four species of the genus are described: H. daedalus sp. nov. from Roan Mountain and the Great Smoky Mountains (Southern Appalachian Mountains, USA), H. flavus sp. nov. and H. geminus sp. nov. from the Yatsugatake Mountains (Honshu, Japan), and H. cataractus sp. nov. from the Malay Archipelago (Borneo and the Moluccas). Dorsal and ventral sculpturing, together with morphometric traits, are shown to be the key characters that allow for the phenotypic discrimination of species within the genus. Furthermore, the morphology of Hypechiniscus is discussed and compared to that of the most similar genera, Pseudechiniscus and Stellariscus. Finally, a diagnostic key to all recognized Hypechiniscus species is provided. [ABSTRACT FROM AUTHOR]

The taxonomy of many groups of meiofauna is challenging due to their low number of diagnostic morphological characters and their small body size. Therefore, with the advent of molecular techniques that provide a new source of traits, many cryptic species have started to be discovered. Tardigrades are not an exception, and many once thought to be cosmopolitan taxa are being found to be complexes of phenotypically similar species. Macrobiotus pallarii Maucci, 1954 was originally described in South Italy and has been subsequently recorded in Europe, America, and Asia. This allegedly wide geographic range suggests that multiple species may be hidden under this name. Moreover, recently, genetic evidence to support this was put forward, and the Macrobiotus pallarii complex has been proposed to accommodate putative species related to M. pallarii. Here, we describe three new pseudocryptic species based on populations that would have been all classified as Macrobiotus pallarii if molecular methods were not employed. Using an integrative taxonomy approach, we analyzed animals and eggs from the topotypic population of Macrobiotus pallarii, together with four other populations of the complex. We recovered four distinct phylogenetic lineages that, despite the overlap of morphometric traits, can be separated phenotypically by subtle but discrete morphological characters. One lineage corresponds to Macrobiotus pallarii, whereas the other three are newly described as Macrobiotus margoae Stec, Vecchi & Bartels, sp. nov. from the USA, Macrobiotus ripperi Stec, Vecchi & Michalczyk, sp. nov. from Poland and Finland, and Macrobiotus pseudopallarii Stec, Vecchi & Michalczyk, sp. nov. from Montenegro. To facilitate species identification, we provide a dichotomous key for species of the M. pallarii complex. Delimitation of these pseudocryptic taxa highlights the need for an integrative approach to uncover the phylum's diversity in full. [ABSTRACT FROM AUTHOR]

Recent years have brought undeniable progress in tardigrade taxonomy, and speciose complexes were detected in a number of phylogenetic lineages. The family Echiniscidae is one such lineage; it is one of the most diverse groups of limno-terrestrial tardigrades and can be characterized as having achieved great evolutionary success. In this contribution, using populations representing several species that originated from the Indomalayan region, we reconstructed phylogenetic affinities within Nebularmis, a recently erected genus within the Echiniscus lineage. Nebularmis auratussp. nov. and Nebularmis burmensissp. nov. are described from the Eastern Yoma Mountains and the Shan Hills (Myanmar), Nebularmis bhutanensissp. nov. is described from the Eastern Himalayas (Bhutan), and Nebularmis indicussp. nov. is described from the foothills of the Western Ghats (Goa, India). Moreover, males are reported in populations of the last two species. All known members of the genus can be phenotypically differentiated based on minute details of their dorsal sculpture and claws. Moreover, a very wide tropical distribution is demonstrated for Nebularmis cirinoi, recorded for the first time from islands of the Malay Archipelago. Furthemore, novel morphological, genetic, and geographic data allowed for the clarification of the generic diagnosis. Currently available data favor a scenario under which Nebularmis evolved in Southeast Asia and later dispersed to other regions of the globe. [ABSTRACT FROM AUTHOR]