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Urban landscapes restrain the distribution of forest‐dwelling species, which may be related to challenging conditions that impair body condition. The dynamics in urban areas lead to the simplification of communities that inhabit forest patches in cities with the turnover of sensitive species for opportunistic ones. In this study, we investigated the effect of urbanization on the body condition and diversity of scorpions at the landscape scale. Sampling was carried out in 10 forest patches in an urban matrix in Brazil, originally covered by a tropical rainforest. The surroundings of the landscape of each forest patch were characterized through the amount of forest, agriculture, and urban land cover. Individual body length, dry, lipid, and muscular masses were used as proxies of Tityus pusillus body condition. In total, 147 scorpions were collected, belonging to the species Ananteris mauryi, T. pusillus, T. stigmurus, and T. neglectus. Forest cover explained 28% of species variation. There was a positive relationship between forest cover and T. pusillus and A. mauryi abundances, while T. stigmurus was negatively affected by forest cover. Species richness and total scorpion abundance were not influenced by landscape metrics. In terms of body condition, only females of T. pusillus were affected by landscape variables, with individuals showing higher body mass with an increase in forest cover. Our results suggest that urban forests can support scorpion assemblages. However, there is a turnover in specialist forest species for opportunistic species. Forest cover is a crucial factor in maintaining healthy scorpion populations in urban areas. [ABSTRACT FROM AUTHOR]

Animal phenotypic traits are utilised in a variety of studies. Often the traits are measured from images. The processing of a large number of images can be challenging; nevertheless, image analytical applications, based on neural networks, can be an effective tool in automatic trait collection.Our aim was to develop a stand‐alone application to effectively segment an arthropod from an image and to recognise individual body parts: namely, head, thorax (or prosoma), abdomen and four pairs of appendages. It is based on convolutional neural network with U‐Net architecture trained on more than a thousand images showing dorsal views of arthropods (mainly of wingless insects and spiders). The segmentation model gave very good results, with the automatically generated segmentation masks usually requiring only slight manual adjustments.The application, named MAPHIS, can further (1) organise and preprocess the images; (2) adjust segmentation masks using a simple graphical editor; and (3) calculate various size, shape, colouration and pattern measures for each body part organised in a hierarchical manner. In addition, a special plug‐in function can align body profiles of selected individuals to match a median profile and enable comparison among groups. The usability of the application is shown in three practical examples.The application can be used in a variety of fields where measures of phenotypic diversity are required, such as taxonomy, ecology and evolution (e.g. mimetic similarity). Currently, the application is limited to arthropods, but it can be easily extended to other animal taxa. [ABSTRACT FROM AUTHOR]

Understanding the effects of environmental conditions on biodiversity may provide cues regarding the resilience of ecological communities facing human activities in tropical forests. Under this scenario, harvestmen are among the most ideal models for understanding the ecological dynamics associated with shifts in environmental conditions. In this study, we evaluated how changes in attributes related to environmental conditions shape harvestmen assemblages in the Atlantic Forest. We assessed the effect of environmental transformation in four forest fragments with different proportions of native forest cover based on their environmental attributes (temperature, humidity, leaf litter depth and cover, and herbaceous vegetation cover) on harvestmen species richness, abundance, and composition. Overall, 865 harvestmen individuals belonging to six families and 41 species were sampled. The effects of environmental conditions on harvestmen assemblages were context‐dependent. In the most conserved fragment, there was an increase in harvestmen richness and abundance with increasing temperature. Furthermore, herbaceous vegetation cover negatively affected harvestmen richness and abundance. Species turnover was the main driver of harvestmen beta diversity in all forest fragments. With the results presented herein, we demonstrate that harvestmen species richness and abundance are modulated by landscape modifications and subsequent alterations in the environment resulting from human‐induced disturbance. Our results highlight the importance of considering environmental transformations at a large spatial scale (i.e., landscape) and local scale (i.e., environmental attributes) to design appropriate conservation strategies for Brazilian Atlantic Forest. [ABSTRACT FROM AUTHOR]

Species extinction has reached unprecedented rates globally, and can cause unexpected ecological cascades. Since Europeans arrived in Australia, many endemic mammals have declined or become extinct, but their ecological roles and outcomes of their reintroduction for ecosystems are poorly understood. Using surveys and novel long‐term exclusion and disturbance experiments, we tested how digging mammal reintroduction affects predatory invertebrates. Mammal exclusion tended to decrease bare ground. Although scorpion burrow abundance increased with bare ground, mammals also had direct negative effects on scorpions. Increased disturbance alone decreased scorpion abundance, but other mechanisms, such as predation, also contributed to the mammal effect. Despite negative associations between scorpions and spiders, both groups increased and spider composition changed following mammal exclusion. Our long‐term research showed that threatened digging mammals drive ecosystem cascades, affecting biota through a variety of pathways. Reintroductions of locally extinct digging mammals can restore ecosystems, but ecosystem cascades may lead to unexpected restructuring. [ABSTRACT FROM AUTHOR]

Burrowing mammals through their digging activities are important ecosystem engineers and bioturbators in grassland ecosystems. Through habitat formation, they can have significant effects on other species in an ecosystem, structuring their abundance and diversity.We analysed the effect of the European ground squirrel (Spermophilus citellus) on spider (Araneae) and harvestman (Opiliones) communities, because these arachnids are the most abundant and dominant predators with a great variety of foraging strategies, and their community composition is strongly influenced by the physical structure of the environment.We established replicate mound plots positioned directly in the centre of ground squirrel mounds with paired off‐mound control plots undisturbed by ground squirrels. We sampled spiders and harvestmen using pitfall traps on 30 ground squirrel mounds and 30 paired off‐mound control plots at two study sites differing in grazing intensity and plant species richness.We found that the response of spiders was site‐specific, while harvestmen responded consistently to disturbances by burrowing mammals. Mounds exhibited increased abundance and species richness of harvestmen at both study sites, while species richness of spiders was increased only in intensively managed grassland. We also detected compositional changes of the arachnid community on the mounds in comparison to the grassland matrix.Our findings indicate that burrowing mammals through physical state changes in abiotic and biotic material modulate the resources for other species and maintain a high diversity of biotic communities in intensively grazed grasslands. [ABSTRACT FROM AUTHOR]

The study of diversity has become increasingly sophisticated, including the use of measures of phylogenetic diversity.We calculate the spatial variation in species richness, taxonomic beta diversity, and alpha and beta phylogenetic diversity (PDα and PDβ, respectively) of Atlantic Forest harvestman communities using a data set containing 556 species from 68 sites, distributed in 12 Brazilian states.We compare the congruence of phylogenetic and taxonomic diversity patterns, and also compare PDα with null model expectations, to check for phylogenetic clustering or overdispersion in communities.Species richness and PDα are correlated, peaking in southern and south‐eastern coastal sites and decreasing towards the interior and towards the north‐east. PDα in north‐eastern sites was higher than expected, while a clustered phylogenetic pattern characterised most other sites.Communities in the southern and south‐eastern regions were dominated by species from the large family Gonyleptidae, presenting a high richness and a low PDα. As the dominance of Gonyleptidae decreased towards the north, where local communities have fewer species, but a higher PDα, they contain representatives of other families. The beta diversity was more sensitive to the compositional changes involving closely related Gonyleptidae species, while PDβ is more influenced by deeper phylogenetic compositional changes, between more distant lineages.Phylogenetic diversity may be of special importance to assess the conservation value of distantly related lineages. These species‐poor groups are less likely to influence taxonomic‐based diversity analyses, but their importance for conservation arises from their phylogenetic distinctiveness, captured by PDα and PDβ measures. [ABSTRACT FROM AUTHOR]

Background: Theraphosidae is a large family of tarantula spiders commonly kept as pets or display animals by zoological institutions. Interest and demand for arachnid medicine have grown over the last decade. While hemolymph analysis could be a fundamental tool for arachnid health assessment, RIs are generally lacking for arachnid species. Objectives: The objectives of this study were to describe the appearance of hemocytes and establish RIs for total and differential hemocyte counts as well as hemolymph glucose and electrolyte concentrations in the Cameroon red tarantula (CRT) (Hysterocrates gigas). Methods: Ninety‐three CRTs were anesthetized using isoflurane or sevoflurane, and hemolymph was collected from the heart. Hemocyte counts were performed using a hemocytometer and trypan blue stain, and differential cell counts were estimated using light microscopy and a Wright stain. Hemocytes were also characterized with transmission electron microscopy (TEM). Hemolymph glucose and electrolyte concentrations were obtained using a blood gas analyzer. The American Society for Veterinary Clinical Pathology (ASVCP) guidelines were used to calculate RIs. Results: The most abundant hemocytes were plasmatocytes, followed by granulocytes, cyanocytes, and prohemocytes. Hemocytes were characterized by TEM except for cyanocytes. All RIs had a broad range, likely due to a combination of population heterogeneity, high biologic variability of the species, and the propensity of samples to clot. Conclusions: The current study is the first to establish RIs for hemolymph cytologic parameters with a sample size of over 20 individuals in any theraphosid species. RIs for CRT hemolymph biochemical analytes are also reported. [ABSTRACT FROM AUTHOR]

Egg attendance is the most common and phylogenetically widespread form of post-ovipositional care among ectotherms. The main benefit of egg attendance is to enhance offspring survival by preventing or attenuating attacks from natural enemies. In arachnids, there are few experimental studies on the benefits of egg attendance, and they pertain to species living in few types of habitats, mainly forests. To understand how the benefits of egg attendance vary in large geographical scales, we need to include species from poorly explored habitats, such as caves. Here, we describe a case of maternal egg attendance in an exclusive cave-dwelling harvestman, Phalangodus briareos. Using a parent removal experiment, we also assessed the benefits of egg attendance. We found that egg attendance improves egg survival because unattended clutches were almost entirely consumed by conspecifics and crickets. When females were maintained on their clutches, egg survival was always high, regardless of female body size. There was a positive effect of clutch size on egg predation, which was higher during nighttime. We suggest that larger clutches emit more chemical cues, attracting more predators in the cave habitat. Finally, we argue that the benefits of egg protection should be higher inside caves when compared to external habitats because food is scarce inside caves and the fauna consists mainly of predators and detritivores. [ABSTRACT FROM AUTHOR]

1. Spatial subsidies, defined as the flow of energy, nutrients, organisms or pollutants from one habitat to another, have been shown to affect the food–web dynamics in a wide range of ecosystems. An important subsidy to riparian communities is the contribution of adult stream insects to terrestrial predators such as birds, bats and lizards, but also invertebrates including ground and web-building spiders. 2. We surveyed 37 first- and second-order forest streams across differing environmental gradients in the Central South Island, New Zealand, to investigate the relationship between potential aquatic prey subsidies and predatory riparian arachnids. We anticipated that stream-insect biomass would be positively associated with riparian arachnids, as a result of emergent adult aquatic insect subsidies to the adjacent habitat. 3. We confirmed positive associations between stream-insect biomass as a predictor variable and riparian arachnid biomass ( R2 = 0.42, F1,34 = 25.2, P < 0.001) and web densities ( R2 = 0.45, F1,14 = 11.5, P < 0.01) respectively as dependent variables after adjusting for the confounding effects of environmental variables. Hierarchical partitioning confirmed the importance of stream insect biomass as a statistically significant contributor to the total explained variance in analyses calculated for arachnid biomass, abundance and web density. 4. A concurrent survey of spider-web density along 20-m transects from the stream edge into the forest indicated a strong decline in web-building spider density moving away from the stream ( R2 = 0.41, F1,158 = 109, P < 0.001), with stream-insect biomass as a significant covariate ( F1,149 = 17.7, P < 0.001). 5. Our results suggest that productivity gradients present in the donor system affect the magnitude of the interaction between adjacent habitats. Productivity gradients may lead to increased reciprocal subsidies through a positive feedback loop involving the predation of spiders and other predatory terrestrial invertebrates by aquatic predators. However, terrestrial insectivores such as birds, bats and lizards that are not readily used as prey by aquatic predators may circumvent the feedback cycle by consuming a large proportion of emergent aquatic-insect biomass. This may lead to asymmetry in the strength of food–web linkages between aquatic and terrestrial habitats. [ABSTRACT FROM AUTHOR]

1. Fields such as ecology, macroecology, and conservation biology rely on accurate and comparable data. This is especially important for mostly unknown and megadiverse taxa such as spiders and regions such as the Mediterranean. Short-term sampling programmes are increasingly seen as the best option for sampling spiders. Comparability of results, however, demands standard procedures both in methodology and in sampling period. Cost-efficiency dictates that this period should be the most species rich. 2. Pitfall trapping was conducted in 23 sites from north to south Portugal, comprising three large-scale environmental zones and many different habitat types, during 10 months in each site. The annual richness pattern, differences in this pattern between areas and habitats, the complementarity between sampling periods and possible environmental correlates of richness were studied. 3. May and June present the optimal time for collecting spiders in Mediterranean areas. Northern areas have a later peak in richness and dense tree-cover sites offer more flexibility for sampling, with a higher proportion of species present at each period throughout the year. 4. Day length is the environmental factor most correlated with species richness. Maximum daily temperature may reduce richness, especially in southernmost areas, where summer temperatures can be extremely harsh. 5. It is recommended that short-term sampling programmes, intended to give a reasonable picture of spider communities in Portugal and in the Iberian Peninsula (and possibly extending to all the Mediterranean), should be conducted during May or June, with variable flexibility according to area and habitat. The proposed suggestions should appeal to everyone working in the field, given the cost-efficiency and comparability of results by adopting a common standardised approach. [ABSTRACT FROM AUTHOR]