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A fundamental understanding of animal sensory systems is crucial for comprehending their interactions with the environment and with other conspecifics. However, knowledge gaps persist, particularly in arachnids like the order Solifugae. While certain solifuge setae and palpal papillae have been studied structurally and electrophysiologically, providing evidence of chemoreception and mechanoreception, the sensilla on their walking legs remain unexplored. Notably, elongated sensilla on the femur and tibia of the 4th walking legs resemble trichobothria in other arachnid orders yet their function remains unknown. Thus, this study investigates whether these sensilla serve a mechanosensory function. Using electrophysiological and behavioral assays on Eremobates pallipes (Eremobatidae), we assessed the response of the elongated 4th leg sensilla to- (i) air particle movement and- (ii) air pressure changes. Air particle movement stimuli were generated using a speaker placed in the near field of the elongated sensilla that emitted low-frequency pure tones (10-1000 Hz). Air pressure stimuli involved forceful blowing on the sensilla. No response to air particle movement was observed, but a mechanosensory response to air pressure stimuli was detected. Electrophysiological data identified a fast-adapting and fast-recovering cell, and behavioral observations revealed a startle response. Our electrophysiology results suggest a mechanosensory role of elongated sensilla on the 4th walking legs of solifuge, indicating that although they are not sensitive enough to detect air particle movement stimuli, they can receive and respond to air pressure stimuli. Our behavioral experiments similarly show that these sensilla are not sensitive enough to detect air particle movement but respond to more forceful mechanosensory stimuli., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

1. Monitoring behavioural dynamics in complex animal environments, such as poultry breeding facilities, poses a challenge. Utilising technological approaches, such as accelerometers, offers a solution to assess long-term changes in reproductive activity at an individual bird level. Specifically, these sensors measure acceleration associated with the position and movements of the body over time. However, it is important to assess the most suitable method for attaching accelerometer tags to ensure they do not negatively impact behaviour and yield high-quality data.2. The potential of tri-axial accelerometer tags for assessing reproductive behaviour in Japanese quail was evaluated. Two attachment methods - a backpack (plastic platform with elastic bands near wing bases) and a patch (accelerometer on fabric glued to the synsacrum region) - were compared. Controls were handled similarly but without tags. Eighteen pairs of females were housed in pens and assessed immediately and 24 h after handling. After a week of habituation, a male from the same treatment group was introduced into each pen on d 8. The reproductive behaviour of the males was recorded using accelerometers and video recordings.3. The results showed that birds with patches were able to remove their conspecific's accelerometer and displayed an increased initial immobility response compared to the control and backpack groups. The presence of accelerometer tags did not impact male/female reproductive interactions nor fear responses to a novel object. From accelerometer recordings, male reproductive behaviour was easily identified as high amplitude fluctuations in the three axial components of the acceleration vectors, which was reflected as large values of dynamic body acceleration (VeDBA).4. In conclusion, the use of backpacks with accelerometers is a useful strategy to address highly relevant and difficult to tackle behavioural topics such as the temporal dynamic of male reproductive behaviour within breeding groups.

This paper addresses the population genetic structure of the forest-dwelling gonyleptid Geraeocormobius sylvarum (Arachnida, Opiliones). Phylogeographic analyses using cytochrome oxidase subunit I (COI) were conducted on 186 individuals from 43 localities in Argentina and Paraguay, arranged into nine operational sectors and defined upon geographic and vegetation features. Given the current environmental uniformity, it was aimed to assess whether molecular fingerprints of G. sylvarum correlate with Pleistocene fragmentation events, inferred through forest contraction/expansion cycles. The network of 87 haplotypes displayed an unstructured pattern; 75 were found in unique localities (54 on single individuals), with most haplotypes restricted to a single operational sector. The calibrated phylogenetic tree revealed significant admixture, with each clade mainly related to one operational sector. Results suggest multiple fragmentation events; most COI diversity arose in the Late Pleistocene/Early Holocene; recent and relict lineages coexist at a few sites. Banks of major rivers (Paraná and Uruguay) in Misiones Province may have served as main refuge areas, with dispersal within each basin being frequent but sporadic across the watershed divide, keeping basins separated for long periods. The split of the Misiones opiliogeographical area into two sectors corresponding to the major basins is proposed., (© 2025 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

Background: Several epidemiological studies have been carried out using Multiple-Locus Variable-number tandem repeat Analysis (MLVA) for M. hyopneumoniae typing. However, a global perspective on the implications of the genetic diversity of this pathogen is lacking., Objective: This study aimed to determine and to analyze the genetic structure of M. hyopneumoniae based on the p97 R1- p146 R3 MLVA typing scheme and to characterize, analyze and compare MLVA types among countries where the information was publicly available., Methods: A set of 797 publicly available data of M. hyopneumoniae p97 R1- p146 R3 MLVA genetic types from six different countries were analyzed using Genalex 6.41 software to characterize loci polymorphism and using Structure 2.3.4 software in order to identify the genetic structure., Results: A total of 185 MLVA types were identified among the analyzed data. For the p97 R1 and p146 R3 loci, most of the molecular variation in M. hyopneumoniae populations was identified within countries. Three genetic clusters and their recombinations were identified globally., Conclusion: M. hyopneumoniae is a genetically diverse pathogen with limited clonality and three well-defined clusters and their combinations were identified in this investigation. The greatest genetic variation of M. hyopneumoniae was observed within countries., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2025 Tamiozzo, García, González-Ittig and Pieters.)

Age and growth patterns of fish provide important information about the effects of environmental disturbances, which can be used as comparative tools in subsequent studies that attempt to assess freshwater quality. The main goal of our study was to provide information on relevant biological aspects of a native fish species used as a bioindicator in an extensive area of South America. In particular, we evaluated the age and growth patterns of Cnesterodon decemmaculatus (Poeciliidae) to establish reference species values and to compare them in different sites along an environmental quality gradient in a South American freshwater system. Water quality assessments indicated increasing environmental degradation downstream, reflecting anthropogenic impacts. The estimated ages of C. decemmaculatus along this quality gradient varied across sampling sites. The longest-lived individuals were those from the reference site, also presenting the highest average age value (almost 2 years). The best model to describe the growth in length of the individuals was the Logistic model. According to the parameters estimated from the growth curves, individuals from the most disturbed site showed slower growth although they reached greater maximum lengths than fish from the other sites. These results suggest that fish would tolerate the adverse conditions of the most altered sites, allocating their energy differentially. Our study provides valuable information on the age and growth patterns of C. decemmaculatus, a species endemic to the Neotropical region and a useful bioindicator in ecotoxicological studies., (© 2024 Fisheries Society of the British Isles.)

Plastic contamination in the Southern Ocean is a growing issue. This study provides the first comprehensive analysis of marine microplastics (MPs) (0.1-5 mm) in surface sediments in Potter Cove and nearby areas around Argentina's Carlini station (25 de Mayo/King George Island, South Shetlands). Sediment samples from 31 sites (2020-2022) were collected to examine whether MP pollution originates from station activities or ocean currents. All samples contained MPs, averaging 0.18 ± 0.12 MPs/g of sediment, mainly microfibers (MFs) and irregular microfragments (MFRs) (0.11-6.23 mm) and irregular microfragments (MFRs) (0.09-4.57 mm). Infrared spectroscopy identified 13 polymer types, including cellulosic materials, polyester, and polyamide, with most MPs < 1 mm, showing aging signs, similar to laundry wear. This widespread distribution suggests contamination may stem from both local activities and external sources. Findings underscore the urgent need for MP pollution management and further research to identify sources and develop effective mitigation strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Seasonal reproductive dynamics and senescence have profound impacts on male fertility, yet these processes remain understudied in scorpions. This study investigates how reproductive parameters-such as testicular mass, sperm quantity, and viability-change over the course of the reproductive season in Urophonius achalensis males. We found that early-season males exhibited higher sperm quality and testicular mass compared to their older counterparts, suggesting that senescence, rather than reproductive effort, drives the decline in sperm viability. Interestingly, isolated males accumulated more sperm without a reduction in viability, highlighting potential mechanisms that preserve sperm quality despite senescence. Body condition also played a key role, with males in better condition showing higher sperm counts but facing a sharper decline in sperm viability as the season progressed, suggesting trade-offs between early reproductive success and later-life reproductive costs. Our findings offer novel insights into the reproductive strategies of scorpions, emphasizing the interplay between senescence, environmental stressors, and reproductive investment. This work provides new insights into the reproductive biology of scorpions, with broader implications for understanding the role of senescence and mating systems in shaping reproductive strategies.

Artificial intelligence (AI) in animal behavior and welfare research is on the rise. AI can detect behaviors and localize animals in video recordings, thus it is a valuable tool for studying social dynamics. However, maintaining the identity of individuals over time, especially in homogeneous poultry flocks, remains challenging for algorithms. We propose using differentially colored "backpack" tags (black, gray, white, orange, red, purple, and green) detectable with computer vision (eg. YOLO) from top-view video recordings of pens. These tags can also accommodate sensors, such as accelerometers. In separate experiments, we aim to: (i) evaluate avian visual perception of the different colored tags; (ii) assess the potential impact of tag colors on social behavior; and (iii) test the ability of the YOLO model to accurately distinguish between different colored tags on Japanese quail in social group settings. First, the reflectance spectra of tags and feathers were measured. An avian visual model was applied to calculate the quantum catches for each spectrum. Green and purple tags showed significant chromatic contrast to the feather. Mostly tags presented greater luminance receptor stimulation than feathers. Birds wearing white, gray, purple, and green tags pecked significantly more at their own tags than those with black (control) tags. Additionally, fewer aggressive interactions were observed in groups with orange tags compared to groups with other colors, except for red. Next, heterogeneous groups of 5 birds with different color tags were videorecorded for 1 h. The precision and accuracy of YOLO to detect each color tag were assessed, yielding values of 95.9% and 97.3%, respectively, with most errors stemming from misclassifications between black and gray tags. Lastly using the YOLO output, we estimated each bird's average social distance, locomotion speed, and the percentage of time spent moving. No behavioral differences associated with tag color were detected. In conclusion, carefully selected colored backpack tags can be identified using AI models and can also hold other sensors, making them powerful tools for behavioral and welfare studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog dachshund-2, suggesting that a new gene facilitated the expression of a new trait. However, various arachnid groups that possess patellae do not have a copy of dachshund-2, disfavoring the direct link between gene origin and trait origin. We investigated the developmental genetic basis for patellar patterning in the harvestman Phalangium opilio, which lacks dachshund-2. Here, we show that the harvestman patella is established by a novel expression domain of the transcription factor extradenticle. Leveraging this definition of patellar identity, we surveyed targeted groups across chelicerate phylogeny to assess when this trait evolved. We show that a patellar homolog is present in Pycnogonida (sea spiders) and various arachnid orders, suggesting a single origin of the patella in the ancestor of Chelicerata. A potential loss of the patella is observed in Ixodida. Our results suggest that the modification of an ancient gene, rather than the neofunctionalization of a new gene copy, underlies the origin of the patella. Broadly, this work underscores the value of comparative data and broad taxonomic sampling when testing hypotheses in evolutionary developmental biology., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

High-latitude ecosystems have been overlooked in carbon budgets, which traditionally focus on mangroves, salt marshes, and seagrasses. The benthic assemblages and their Nature Contributions to People in Namuncurá - Burdwood Bank I and II, two offshore sub-Antarctic Marine Protected Areas (MPAs), are the conservation values. Here we show that the carbon reservoirs of these MPAs can be greater than those of their Antarctic counterparts, which, together with their extension, emphasize the need to maintain their protected status. Considering their total area, these MPAs stored in biomass 52,085.78 Mg C, corresponding 34,964.16 Mg to organic carbon (OC) and 17,121.62 Mg to inorganic carbon (IC). Surficial sediments stored 933,258,336 Mg C with 188,089,629 Mg of OC and 745,168,707 Mg of IC. However, when accounting for CO 2 production through CaCO 3 precipitation, the IC fractions decrease to 3,150.37 Mg C and 137,111,042 Mg C for biomass and sediments, respectively. We assume low sediment deposition due to the oceanic location, as direct sedimentation rates for these areas are unavailable. Most blue carbon assessments have focused solely on OC, despite the formation of CaCO 3 releases CO 2 , decreasing net carbon storage. We compared various approaches for incorporating carbonates into carbon estimations. These results underscore the importance of including IC into carbon assessments and highlights the importance of sub-Antarctic benthic ecosystems as nature-based solutions to climate change., (© 2024. The Author(s).)

The evolutionary dynamics of the ecoregions of southern South America and the species that inhabit them have been poorly studied, and few biogeographic hypotheses have been proposed and tested. Quaternary climatic oscillations are among the most important processes that have led to the current distribution of genetic variation in different regions of the world. In this work, we studied the evolutionary history and distribution of the Córdoba vesper mouse (Calomys venustus), a characteristic rodent of the region of which little is known about its natural history. Since the population dynamics of this species are influenced by climatic factors, this rodent is a suitable model to study the effects of Quaternary climatic oscillations in central Argentina. The mitochondrial cytochrome b gene was sequenced to analyze the phylogeography of C. venustus, and ecological niche modeling tools were used to map its potential distributions. The results of these approaches were combined to provide additional spatially explicit information about this species' past. Our results suggest that the Espinal was the area of origin of this species, which expanded demographically and spatially during the last glacial period. A close relationship was found between the Espinal and the Mountain Chaco. These results are consistent with previous studies and emphasize the role of the Espinal in the biogeographic history of southern South America as an area of origin of several species., (© 2024 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

Sexual dimorphism (SD), the divergence of secondary sexual traits between males and females within a species, can arise from diverse evolutionary forces, such as natural selection, mate choice, and intrasexual competition. Allometric scaling patterns of dimorphic traits are related to their functional roles and the different selective pressures that affect each sex. Generally, traits that threaten rivals involved in intrasexual competition tend to exhibit the highest allometric slopes. Conversely, non-sexual traits often display isometric scaling, while genitalia and traits in direct contact between the sexes during courtship and copulation typically show hypoallometry. A good approach to study patterns of SD and allometry is to complement interspecific studies with analyzes of case studies, where the functional aspect is known in detail. Here, we review the occurrence of SD and evaluation of allometry in the Order Scorpiones, allowing us to compare general trends in a broader comparative framework within the group. In addition, we examined SD and allometric slopes of multiple traits (including somatic traits used in sexual and non-sexual interactions, as well as genitalia) in adult individuals of the scorpion Timogenes elegans (Scorpiones, Bothriuridae). We found that at an interspecific level there was a variation in SD between species and morphological traits, with most traits showing a male-biased SD, except for the chelicerae, which were found to be wider in females. Regarding SD studies, we found relatively few reports of functional allometry showing differences in allometric patterns between species. The results in T. elegans follow some of the general patterns found in other scorpions. We found hypoallometry in genital traits and hyperallometry in the pedipalps of both sexes, with steeper allometric slopes observed for pedipalp height in males. These results suggest that genital traits are under stabilizing selective pressure, while pedipalps in both sexes may be under natural and sexual selective pressure. Understanding allometric patterns and their relationship to function in scorpions provides significant insights into the evolutionary pressures driving the divergence of morphological traits used in both sexual and non-sexual contexts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Glyphosate is the most widely utilized herbicide worldwide due to its effectiveness in controlling agricultural weeds. However, its persistence in aquatic ecosystems has raised concerns about the well-being of non-target organisms such as fish. This study aimed to evaluate the effects of chronic exposure (21 days) to glyphosate or its formulated product Roundup Transorb R®, at an environmentally relevant concentration permitted by regulations in certain countries (65 μg/L of glyphosate), on the locomotor activity and reproductive success of the fish Jenynsia lineata, as well as on the morphology/development and locomotor activity of its offspring, as intergenerational effects. Neither the pure nor formulated herbicide altered the distance traveled and velocity of adult fish exposed to the herbicide (F0), but they negatively affected reproductive success, decreasing the percentage of positive response to the presence of the female, reducing the number of gravid females, causing abortions, and lowering offspring survival (F1). In the F1 generation, a decrease in weight and length was noted along with developmental abnormalities in both treatment groups (pure or formulated glyphosate), with the formulation causing more harm. Observed developmental abnormalities included muscle atrophy, ascites, pigmentary disorders, vertebral agenesis, spinal deviation, and exophthalmia. Furthermore, parental exposure to pure glyphosate led to an increase in the distance traveled and velocity of F1 (hyperlocomotion), whereas exposure to the formulated product resulted in a decrease in these behaviors (hypolocomotion) of F1. These findings highlight the toxic effects of glyphosate at very low concentrations, although varying between pure and formulated, and demonstrate the intergenerational consequences of herbicide exposure, underscoring the risk to the survival of fish offspring in glyphosate-contaminated environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that may have influenced the work reported in this study., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Two new species of the genus Acrographinotus (Opiliones, Laniatores, Gonyleptidae) are described from protected areas placed on sub-Andean ranges: Acrographinotus tariquiae sp. nov. from Tariquía National Reserve, southern Bolivia, and A. calilegua sp. nov. from Calilegua National Park, northwestern Argentina. They represent the southernmost representatives, and in the case of A. calilegua sp. nov., the lowest altitudinal record of this wide-ranged Andean genus. Acrographinotus tariquiae sp. nov. is compared with its most similar congeners, A. erectispina (type species) and A. niawpaq, from which it differs by the armature of trochanter IV, femur IV and ventral anal plate of the male. Differences between A. calilegua sp. nov. and A. tariquiae sp. nov., especially considering small-sized and β-type males of the latter, are detailed. The genus diagnosis is updated. A key to identify males of the nine confirmed nominal Acrographinotus species is provided for the first time.

Recent advances in higher-level invertebrate phylogeny have leveraged shared features of genomic architecture to resolve contentious nodes across the tree of life. Yet, the interordinal relationships within Chelicerata have remained recalcitrant given competing topologies in recent molecular analyses. As such, relationships between topologically unstable orders remain supported primarily by morphological cladistic analyses. Solifugae, one such unstable chelicerate order, has long been thought to be the sister group of Pseudoscorpiones, forming the clade Haplocnemata, on the basis of eight putative morphological synapomorphies. The discovery, however, of a shared whole genome duplication placing Pseudoscorpiones in Arachnopulmonata provides the opportunity for a simple litmus test evaluating the validity of Haplocnemata. Here, we present the first developmental transcriptome of a solifuge (Titanopuga salinarum) and survey copy numbers of the homeobox genes for evidence of systemic duplication. We find that over 70% of the identified homeobox genes in T. salinarum are retained in a single copy, while representatives of the arachnopulmonates retain orthologs of those genes as two or more copies. Our results refute the placement of Solifugae in Haplocnemata. Subsequent reevaluation of putative interordinal morphological synapomorphies among chelicerates reveals a high incidence of homoplasy, reversals, and inaccurate coding within Haplocnemata and other small clades, as well as Arachnida more broadly, suggesting existing morphological character matrices are insufficient to resolve chelicerate phylogeny., (© 2023 The Authors. Evolution & Development published by Wiley Periodicals LLC.)

Global warming poses a threat to lizard populations by raising ambient temperatures above historical norms and reducing thermoregulation opportunities. Whereas the reptile fauna of desert systems is relatively well studied, the lizard fauna of saline environments has not received much attention and-to our knowledge-thermal ecology and the effects of global warming on lizards from saline environments have not been yet addressed. This pioneer study investigates the thermal ecology, locomotor performance and potential effects of climate warming on Liolaemus ditadai, a lizard endemic to one of the largest salt flats on Earth. We sampled L. ditadai using traps and active searches along its known distribution, as well as in other areas within Salinas Grandes and Salinas de Ambargasta, where the species had not been previously recorded. Using ensemble models (GAM, MARS, RandomForest), we modeled climatically suitable habitats for L. ditadai in the present and under a pessimistic future scenario (SSP585, 2070). L. ditadai emerges as an efficient thermoregulator, tolerating temperatures near its upper thermal limits. Our ecophysiological model suggests that available activity hours predict its distribution, and the projected temperature increase due to global climate change should minimally impact its persistence or may even have a positive effect on suitable thermal habitat. However, this theoretical increase in habitat could be linked to the distribution of halophilous scrub in the future. Our surveys reveal widespread distribution along the borders of Salinas Grandes and Salinas de Ambargasta, suggesting a potential presence along the entire border of both salt plains wherever halophytic vegetation exists. Optimistic model results, extended distribution, and no evidence of flood-related adverse effects offer insights into assessing the conservation status of L. ditadai, making it and the Salinas Grandes system suitable models for studying lizard ecophysiology in largely unknown saline environments., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Six species of freshwater turtles dominate the Chaco-Pampa Plain in southern South America and their parasites have been relatively understudied, with most records concentrated in Brazil. Particularly in Argentina, there are only scattered records of parasites for most of the turtles that inhabit the region, leaving a large knowledge gap. The purpose of the present contribution is to increase the knowledge of the internal parasites of six species of freshwater turtles from Argentina, after 15 years of fieldwork, by providing new hosts and additional geographic records for many host-parasite relationships. Some molecular sequences of the studied parasites were provided as a tool for better species identification. We processed 433 stomach and fecal samples from live individuals and visceral and soft tissue samples from 54 dissected turtles collected from a wide range and different ecoregions. We found 6230 helminths belonging to 18 taxa (one cestode, 11 digeneans and six nematodes). Fourteen new parasite-host associations are reported here, and for the first time parasites are recorded for Phrynops williamsi. This work contributes significantly to the knowledge of the parasitofauna in freshwater turtles in Argentina, providing a detailed list of parasites present in each turtle species and reporting molecular characters for future studies.

Background: Triatoma garciabesi and T. guasayana are considered secondary vectors of Trypanosoma cruzi and frequently invade rural houses in central Argentina. Wing and head structures determine the ability of triatomines to disperse. Environmental changes exert selective pressures on populations of both species, promoting changes in these structures that could have consequences for flight dispersal. The aim of this study was to investigate the relationship between a gradient of anthropization and phenotypic plasticity in flight-related traits., Methods: The research was carried out in Cruz del Eje and Ischilín departments (Córdoba, Argentina) and included 423 individuals of the two species of triatomines. To measure the degree of anthropization, a thematic map was constructed using supervised classification, from which seven landscapes were selected, and nine landscape metrics were extracted and used in a hierarchical analysis. To determine the flight capacity and the invasion of dwellings at different levels of anthropization for both species, entomological indices were calculated. Digital images of the body, head and wings were used to measure linear and geometric morphometric variables related to flight dispersion. One-way ANOVA and canonical variate analysis (CVA) were used to analyze differences in size and shape between levels of anthropization. Procrustes variance of shape was calculated to analyze differences in phenotypic variation in heads and wings., Results: Hierarchical analysis was used to classify the landscapes into three levels of anthropization: high, intermediate and low. The dispersal index for both species yielded similar results across the anthropization gradient. However, in less anthropized landscapes, the density index was higher for T. garciabesi. Additionally, in highly anthropized landscapes, females and males of both species exhibited reduced numbers. Regarding phenotypic changes, the size of body, head and wings of T. garciabesi captured in the most anthropized landscapes was greater than for those captured in less anthropized landscapes. No differences in body size were observed in T. guasayana collected in the different landscapes. However, males from highly anthropized landscapes had smaller heads and wings than those captured in less anthropized landscapes. Both wing and head shapes varied between less and more anthropogenic environments in both species., Conclusions: Results of the study indicate that the flight-dispersal characteristics of T. garciabesi and T. guasayana changed in response to varying degrees of anthropization., (© 2024. The Author(s).)

Plastic pollution in the Southern Ocean around Antarctica is a growing concern, but many areas in this vast region remain unexplored. This study provides the first comprehensive analysis of marine microplastic (MPs) concentrations in Potter Cove, located near the Argentinian Carlini research station on 25 de Mayo/King George Island, Antarctica. Water samples were collected at 14 sites within the cove, representing various influences from the station's activities. Two sampling methods were used: a 5 L Niskin bottle and an in-situ filtering device called Microfilter, allowing for large water volumes to be filtered. MPs were found in 100 % of the samples. Microfilter samples ranged from 0.02 to 2.14 MPs/L, with a mean concentration of 0.44 ± 0.44 MPs/L. Niskin bottle samples showed concentrations from 0.40 to 55.67 MPs/L, with a mean concentration of 19.03 ± 18.21 MPs/L. The dominant types of MPs were anthropogenic black, transparent, and pink microfibers (MFs) measuring between 0.11 and 3.6 mm (Microfilter) and 0.06 to 7.96 mm (Niskin bottle), with a median length of 0.01 mm for both methods. Transparent and black irregular microfragments (MFRs) with diameters from 0.10 to 5.08 mm and a median diameter of 0.49 mm were also prevalent. FTIR-spectroscopy revealed the presence of 14 types of polymers. Cellulose-based materials and polyethylene terephthalate were the most abundant in MFs, while polyurethanes and styrene-based copolymers dominated in MFRs. MPs were more abundant near the Carlini station. Compared to other coastal Antarctic areas, the MPs in the cove were relatively abundant and mostly smaller than 1 mm. Local activities on the island were identified as the primary source of MPs in the cove, and the cyclonic water circulation likely affects the distribution of small-sized particles. To protect the ecosystem, reducing plastic usage, improving waste management, regulating MPs debris, and enhancing wastewater practices are essential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Although many small vertebrates are capable of performing high-speed behaviors, most studies continue to focus on low-resolution temporal scales (>>1 s). Herein, we present video-recordings, behavior time series, and the computer software for video-analysis of Japanese quail within social groups. Home-boxes were monitored using both top and side video-cameras. High-resolution ethograms were developed for analyses. Pairs of females were assigned as either controls or using one of two methods for attachment of an accelerometer (patch or backpack). Behavior was recorded during 1 h on the first 2-days, sampled at 1 s intervals (days 1 and 2). On day 8, an unfamiliar male was placed in the home-box and its behavior was recorded during the first 10 min, sampled every 1/15 s. Male accelerometer recordings were also obtained. Video-recordings and resulting detailed high-resolution behavioral time series are valuable for reuse in comparative studies regarding the temporal dynamics of behavior within social environments. In addition, they are necessary for the assessment of novel machine learning algorithms that could be used for deciphering the output of accelerometer recordings., (© 2024. The Author(s).)

Birds living at high latitudes perceive the photoperiod through deep-brain photoreceptors (DBP) located in deep-brain neurons. During long photoperiods the information transmitted by these photoreceptors increases the activity of the hypothalamic-pituitary-gonadal (HPG) axis, leading to gonadal development. The presence of photopigments such as VA-Opsin, Opn4, Opn5 and Opn2 in brain areas implicated in reproductive behaviors has been firmly established in several avian species with seasonal breeding, whereas their existence in opportunistic breeding birds remains unconfirmed. The Eared Dove is an urban and peri-urban dove that breeds throughout the year. Males of this species do not exhibit the typical gonadal regression/recrudescence cycle, thus posing the question of what occurs upstream of the HPG axis. We addressed this issue by first studying the presence of diverse opsins located in DBP in the brains of Eared Dove males and whether these photopigments changed their expression throughout the year. We carried out an immunohistochemistry analysis on three different opsins: Opn2 (rhodopsin), Opn3 and Opn5. Our results demonstrate the discrete neuroanatomical distribution of these opsins in the brain of Eared Dove males and strongly indicate different seasonal expressions. In the anterior region of the hypothalamus, Opn2-positive cells were detected throughout the year. By contrast, Opn5 was found to be strongly and seasonally expressed during winter in the anterior and the hypothalamic region. Opn3 was also found to be significantly and seasonally expressed during winter in the hypothalamic region. We thus demonstrate for the first time that males of the Eared Dove, have three different deep-brain opsin-expressing photoreceptors with differential location/distribution in the anterior and hypothalamic region and differential seasonality. The persistence of Opn2 and the strong seasonal expression of nonvisual photopigments Opn3 and Opn5 in two areas of the avian brain, which are associated with reproduction, could be the primary distinction between seasonal and opportunistic breeders., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Southern Ocean organisms are considered particularly vulnerable to Ocean acidification (OA), as they inhabit cold waters where calcite-aragonite saturation states are naturally low. It is also generally assumed that OA would affect calcifying animals more than non-calcifying animals. In this context, we aimed to study the impact of reduced pH on both types of species: the ascidian Cnemidocarpa verrucosa sp. A, and the bivalve Aequiyoldia eightsii, from an Antarctic fjord. We used gene expression profiling and enzyme activity to study the responses of these two Antarctic benthic species to OA. We report the results of an experiment lasting 66 days, comparing the molecular mechanisms underlying responses under two pCO 2 treatments (ambient and elevated pCO 2 ). We observed 224 up-regulated and 111 down-regulated genes (FC ≥ 2; p-value ≤ 0.05) in the ascidian. In particular, the decrease in pH caused an upregulation of genes involved in the immune system and antioxidant response. While fewer differentially expressed (DE) genes were observed in the infaunal bivalve, 34 genes were up-regulated, and 69 genes were downregulated (FC ≥ 2; p-value ≤ 0.05) in response to OA. We found downregulated genes involved in the oxidoreductase pathway (such as glucose dehydrogenase and trimethyl lysine dioxygenase), while the heat shock protein 70 was up-regulated. This work addresses the effect of OA in two common, widely distributed Antarctic species, showing striking results. Our major finding highlights the impact of OA on the non-calcifying species, a result that differ from the general trend, which describes a higher impact on calcifying species. This calls for discussion of potential effects on non-calcifying species, such as ascidians, a diverse and abundant group that form extended three-dimensional clusters in shallow waters and shelf areas in the Southern Ocean., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Background: Caries is a worldwide distributed oral disease of multifactorial nature, with Streptococcus mutans being the most commonly isolated bacterial agent. The glycosyltransferases of this bacterium would play an essential role in the aetiology and pathogenesis of caries., Aim: We explored how the glucosyltransferase-B (gtf-B) gene variability of S. mutans from children in central Argentina correlated with their caries experience and how these strains were genetically related to those of other countries., Design: Dental examinations were performed on 59 children; dmft and DMFT indexes were calculated. From stimulated saliva, S. mutans was grown and counted (CFU/mL). From bacterial DNA, the gtf-B gene was amplified and sequenced. Alleles were identified and their genealogical relationships established. Clinical, microbiological, and genetic variables were correlated with caries experience. Our sequences were included in a matrix with those from 16 countries (n = 358); genealogical relationships among alleles were obtained. Population genetic analyses were performed for countries with >20 sequences., Results: The mean dmft + DMFT was 6.45. Twenty-two gtf-B alleles were identified here, which showed low genetic differentiation in the network. Caries experience was correlated with CFU/mL, but not with allele variation. Low differentiation was found among the 70 alleles recovered from the 358 sequences and among the countries analyzed., Conclusion: In this study, caries experience in children was correlated with the number of CFU/mL of S. mutans but not with the gtf-B gene variability. Combined genetic analyses of worldwide strains support the theory that this bacterium experienced population expansions, probably associated with agriculture development and/or food industrialization., (© 2023 BSPD, IAPD and John Wiley & Sons Ltd.)

Ectothermic animals can raise their body temperature under varying circumstances. Two such situations occur during sexual activity (as metabolic rate rises during copulatory movements) and during infection (to control pathogens more effectively). We have investigated these two situations using Tenebrio molitor males. We recorded the copulatory courtship behavior of sick (= infected with Metharizium robertsii fungus) vs healthy males and its link with body temperature. We predicted a positive relation between copulatory courtship (measured as antennal and leg contact behavior) and body temperature, especially in sick males. We found that the intensity of contacts correlated with increased body temperature in sick males. Previous studies in this species indicated that partner females laid fewer eggs after mating with sick males above a certain male body temperature threshold. Thus, our present findings suggest that females may detect male infection via intensity of antennal-mediated courtship, body temperature or their combination. If this is the case, females may assess male cues directly related to health status such as body temperature., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Cargnelutti et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Seasonality considerably impacts on the life of organisms and leads to numerous evolutionary adaptations. Some species face seasonal changes by entering a diapause during different life stages. During adulthood, a diapause in the non-reproductive period can affect male gametogenesis as, for example, it occurs in insects. Spiders are distributed worldwide and show a variety of life cycles. However, data on spiders' life cycles and seasonal adaptations are limited. Here, we explored the effect of reproductive diapause in a seasonal spider for the first time. We used the South American sand-dwelling spider Allocosa senex as a model as this species is diplochronous, meaning that individuals live two reproductive seasons, with juveniles and adults overwintering in burrows. It has been observed that individuals of this species reduce their metabolism during the non-reproductive season, diminishing prey consumption and locomotion to a minimum. This species is also well-known for exhibiting wandering and courting females and sedentary males. We analyzed spermatogenesis throughout the male's life cycle and described the male's reproductive system and spermiogenesis using light and transmission electron microscopy. We found that spermatogenesis in A. senex is asynchronous and continuous. However, when males face the non-reproductive season, the late spermatogenic stages and spermatozoa decline, causing an interruption but not a total arrest of this process. This seasonality is also reflected in smaller testes' size in males from the non-reproductive season than in other periods. The mechanisms and constraints are unknown, but they could be related to the metabolic depression during this life cycle period. Since sex-role reversal apparently sets a low-intensity sperm competition scenario compared with other wolf spiders, surviving two reproductive seasons may balance mating opportunities by distributing them between both periods. Thus, the partial interruption of spermatogenesis during diapause could allow new mating encounters during the second reproductive season., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Sexual selection often shapes social behavioural activities, such as movement in the environment to find possible partners, performance of displays to signal dominance and courtship behaviours. Such activities may be negatively influenced by increasing temperatures, especially in ectotherms, because individuals either have to withstand the unfavourable condition or are forced to allocate more time to thermoregulation by increasing shelter seeking behaviour. Thus, they "miss" opportunities for social and reproductive interactions. Moreover, behavioural displays of ectotherms closely depend on temperature; consequently, mate choice behaviours may be disrupted, ultimately modifying sexual selection patterns. Therefore, it would be interesting to elucidate how increasing temperatures associated with global warming may influence activity and social interactions in the species' natural habitat and, specifically how high temperatures may modify intersexual interactions. Consequently, our aim was to explore differences in the daily pattern of social interactions in an ectotherm model, Tropidurus spinulosus, in two thermally different habitats and to determine how high temperatures modify mate choice. High environmental temperatures were found to be associated with a bimodal pattern in daily activity, which was closely linked to the daily variations in the thermal quality of the habitat; whereas the pattern and frequency of social displays showed less plasticity. The time allocated to mate choice generally decreased with increasing temperature since individuals increased the use of thermal refuges; this result supports the hypothesis of "missed opportunities". Moreover, at high temperatures, both sexes showed changes in mate selection dynamics, with females possibly "rushing" mate choice and males showing an increase in intermale variability of reproductive displays. In our ectotherm model, plastic adjustments in the behavioural activity pattern induced by high temperatures, plus the modification of the displays during courtship may ultimately modify mate choice patterns and sexual selection dynamics., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Rossi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The West Antarctic Peninsula (WAP) is a hotspot of physical climate change, especially glacial retreat, particularly in its northern South Shetland Islands (SSI) region. Along coastlines, this process is opening up new ice-free areas, for colonization by a high biodiversity of flora and fauna. At Potter Cove, in the SSI (Isla 25 de Mayo/King George Island), Antarctica, colonization by macroalgae was studied in two newly ice-free areas, a low glacier influence area (LGI), and a high glacier influence area (HGI) differing in the presence of sediment run-off and light penetration, which are driven by levels of glacial influence. We installed artificial substrates (tiles) at 5 m depth to analyze benthic algal colonization and succession for four years (2010-2014). Photosynthetic active radiation (PAR, 400-700 nm), temperature, salinity, and turbidity were monitored at both sites in spring and summer. The turbidity and the light attenuation (K d ) were significantly lower at LGI than at HGI. All tiles were colonized by benthic algae, differing in species identity and successional patterns between areas, and with a significantly higher richness at LGI than HGI in the last year of the experiment. We scaled up a quadrat survey on the natural substrate to estimate benthic algal colonization in newly deglaciated areas across Potter Cove. Warming in recent decades has exposed much new habitat, with macroalgae making up an important part of colonist communities 'chasing' such glacier retreat. Our estimation of algal colonization in newly ice-free areas shows an expansion of ∼0.005-0.012 km 2 with a carbon standing stock of ∼0.2-0.4 C tons, per year. Life moving into new space in such emerging fjords has the potential to be key for new carbon sinks and export. In sustained climate change scenarios, we expect that the processes of colonization and expansion of benthic assemblages will continue and generate significant transformations in Antarctic coastal ecosystems by increasing primary production, providing new structures, food and refuge to fauna, and capturing and storing more carbon., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dolores Deregibus reports equipment, drugs, or supplies and travel were provided by Ministerio de Ciencia y Tecnología. Dolores Deregibus reports travel was provided by Coastcarb., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The male genitalia of pholcid spiders, which is one of the most species-rich spider families, are characterized by a procursus, which is a morphologically diverse projection of the copulatory organ. It has been shown that the procursus interacts with the female genitalia during copulation. Here, we investigate the function of the procursus in Gertschiola neuquena , a species belonging to the early branched and understudied subfamily Ninetinae, using behavioural and morphological data. Although many aspects of the copulatory behaviour of G. neuquena follow the general pattern described for the family, males use only one pedipalp during each copulation. Based on our micro-CT analysis of cryofixed mating pairs using virgin females, we can show that the long and filiform procursus is inserted deeply into the unpaired convoluted female spermatheca, and the intromittent sclerite, the embolus, is rather short and stout only reaching the most distal part of the female sperm storage organ. Histological data revealed that sperm are present in the most proximal part of the spermatheca, suggesting that the procursus is used to allocate sperm deeply into the female sperm storage organ. This represents the first case of a replacement of the sperm allocation function of the intromittent sclerite in spiders., Competing Interests: We have no competing interests., (© 2023 The Authors.)

Crotalines (pitvipers) in the Americas are distributed from southern Canada to southern Argentina, and are represented by 13 genera and 163 species that constitute a monophyletic group. Their phylogenetic relationships have been assessed mostly based on DNA sequences, while morphological data have scarcely been used for phylogenetic inquiry. We present a total-evidence phylogeny of New World pitvipers, the most taxon/character comprehensive phylogeny to date. Our analysis includes all genera, morphological data from external morphology, cranial osteology and hemipenial morphology, and DNA sequences from mitochondrial and nuclear genes. We performed analyses with parsimony as an optimality criterion, using different schemes for character weighting. We evaluated the contribution of the different sources of characters to the phylogeny through analyses of reduced datasets and calculation of weighted homoplasy and retention indexes. We performed a morphological character analysis to identify synapomorphies for the main clades. In terms of biogeography, our results support a single colonization event of the Americas by pitvipers, and a cladogenetic event into a Neotropical clade and a North American/Neotropical clade. The results also shed light on the previously unstable position of some taxa, although they could not sufficiently resolve the position of Bothrops lojanus, which may lead to the paraphyly of either Bothrops or Bothrocophias. The morphological character analyses demonstrated that an important phylogenetic signal is contained in characters related to head scalation, the jaws and the dorsum of the skull, and allowed us to detect morphological convergences in external morphology associated with arboreality., (© 2023 Willi Hennig Society.)

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications., (© 2022 The Ecological Society of America.)

Molting is an important process in which old and worn feathers are exchanged for new ones. Plumage color is determined by pigments such as carotenes, melanin and by the ultrastructure of the feather. The importance of plumage coloration has been widely studied in different groups of birds, generally at a particular time of the year. However, plumage coloration is not static and few studies have addressed the change in plumage color over time and its relationship to reproductive tasks. The Eared Dove (Zenaida auriculata, Des Murs, 1847) has a melanistic coloration with sexual dichromatism in different body regions. The Eared Dove´s crown is the most exposed body region during the bowing display. Our objective was therefore to accurately determine the molting period of the crown feathers and study the seasonal variation in their coloration in females and males. Our findings indicate a molting period of 6 months (January to June). The new feathers are undergoing changes in their coloration from July to December. During that period we apply an avian vision model then enabled us to reveal a seasonal variation in the coloration of the crown feathers in both sexes, as given by a change in the chromatic distances. The highest values in the chromatic distances towards the reproductive period are given by a change in the UV-violet component of the spectrum, indicating changes in the microstructure of the feather. This change in crown coloration towards the breeding season could be linked to reproductive behaviors., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Valdez, Benitez-Vieyra. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

We describe Bothriurus mistral n. sp. (Scorpiones, Bothriuridae) from the Chilean north-central Andes of the Coquimbo Region. This is the highest elevational discovery for Bothriurus in the western slopes of the Andes. This species was collected in the Estero Derecho Private Protected Area and Natural Sanctuary as part of the First National Biodiversity Inventory of Chile of the Integrated System for Monitoring and Evaluation of Native Forest Ecosystems (SIMEF). Bothriurus mistral n. sp. is closely related to Bothriurus coriaceus Pocock, 1893, from the lowlands of central Chile. This integrative research includes a combination of traditional morphometrics and geometric morphometric analyses to support the taxonomic delimitation of the species., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Ojanguren-Affilastro et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The sex-biased dispersal and kinship dynamics are important factors shaping the spatial distribution of individuals and are key parameters affecting a variety of ecological and evolutionary processes. Here, we studied the spatial distribution of related individuals within a population of corn mice Calomys musculinus in a seasonal cycle to infer dispersal patterns. The sampling was carried out from spring 2005 to winter 2006 in field borders of intensively managed agroecosystems. Genotyping data from 346 individuals with 9 microsatellites showed spatial genetic structure was weak for males, but not for females. The results indicate a complex spatial kinship dynamic of related females across all seasons. Which, contrary to our expectations, dispersal distances decrease with the increase of the population abundance. Meanwhile, male dispersal distances were greater when population abundance increased and thus the availability of active females. Males disperse greater distances to mate and sire offspring with distant females as a possible inbreeding avoidance mechanism. This study shows that C. musculinus is capable of much greater scattering distances than previously reported and that dispersal occurs fluidly and without barriers across the agroecosystem. The indirect benefit of dispersal on individual fitness could be related to relaxing the competition in the natal area and increasing the mating rate. Our study highlights the value of combining genetic relatedness, fieldwork observations, and behavioral data to estimate dispersal at a fine geographical scale., Competing Interests: The authors declare that they have no conflict of interest., (© The Author(s) 2022. Published by Oxford University Press on behalf of Editorial Office, Current Zoology.)

Rapid regional warming causing glacial retreat and melting of ice caps in Antarctica leads benthic filter-feeders to be exposed to periods of food shortage and high respiratory impairment as a consequence of seasonal sediment discharge in the West Antarctic Peninsula coastal areas. The molecular physiological response and its fine-tuning allow species to survive acute environmental stress and are thus a prerequisite to longer-term adaptation to changing environments. Under experimental conditions, we analyzed here the metabolic response to changes in suspended sediment concentrations, through transcriptome sequencing and enzymatic measurements in a highly abundant Antarctic ascidian. We found that the mechanisms underlying short-term response to sedimentation in Cnemidocarpa verrucosa sp. A involved apoptosis, immune defense, and general metabolic depression. These mechanisms may be understood as an adaptive protection against sedimentation caused by glacial retreat. This process can strongly contribute to the structuring of future benthic filter-feeder communities in the face of climate change., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Triatoma guasayana (Hemiptera, Reduviidae), considered a secondary vector of Chagas disease, invades rural dwellings through flight dispersal during the warm season in semi-arid Chaco of Argentina. The objective of this study was to define and compare morphometrics features in the relative body size and wing shape of T. guasayana related to temperature and rainfall between spring, summer and end of summer. A total of 188 adults were collected in rural communities in the northwest of the province of Córdoba (central Argentina). Relative body size [body length (mm) / wing length (mm)] and 11 landmarks on the right wing were recorded. The temperature ( °C) and precipitation (mm) data were extracted from the MODIS sensor and Terra Climate dataset, respectively. Correlations between climatic variables and morphological variation were analyzed using Partial Least Square (PLS). Males at the end of summer were smaller than those at spring or summer (F = 4.48; df = 2; p = 0.01), whereas females were similar in relative body size at all seasons (F = 0.76; df = 2; p = 0.47). The PLS in males showed a correlation between wing shape and temperature (r = 0.48; p = 0.03) and precipitation (r = 0.50; p = 0.02) while in females only the temperature was the correlation significant (r = 0.35; p = 0.03). Triatoma guasayana has elongated and thin wings in spring that become short and wide at the end of summer. The morphotype of early summer could allow sustained long-duration flights, while the morphotype of end of summer would be related to short flights, correlated with the dispersive behavior of the species. The results in this study suggest that wing morphology of T. guasayana has phenotypic plasticity, and that temperature and rainfall could be considered modulator factors during the developmental stage., (Copyright © 2022. Published by Elsevier B.V.)

The increasing contamination of water bodies with mercury raises concerns about its possible effects on aquatic organisms. The combined use of several biomarkers allows researchers to study the impact of a chemical at different levels of biological organization. In the present work, we determined the response of histological (gills and liver), somatic (condition factor and hepato-somatic index), and behavioral (predator-prey relationship, through the presentation of a computer-animated image) biomarkers in the native species Psalidodon eigenmanniorum exposed to 100 µg L -1 of inorganic Hg (IHg) during 96 h. We also assessed whether there was a change in the biomarkers analyzed after 7 days in Hg-free water compared with those exposed to IHg. In exposed fish, IHg caused damage to the gills and liver tissues. The condition factor showed no difference between IHg-exposed organisms and control organisms, while the hepato-somatic index was lower in IHg-exposed fish. As for the behavioral analyses, it was observed that the presentation of a stimulus induced changes in the behavioral responses of fish exposed to IHg, which showed a heightened state of alertness with respect to control. On the other hand, after 7 days in Hg-free water, the organisms generally showed no changes in biomarkers compared with IHg-exposed fish. Our results contribute new data on IHg toxicity in a native species and provide information on the plasticity of damage to reverse itself. Furthermore, this work provides baseline information for environmental assessments in water bodies where mercury is present., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The biodiversity of Neotropical region is affected by anthropogenic disturbance. Throughout Brazil, Argentina and Uruguay, the native fish, Cnesterodon decemmaculatus, is well distributed and widely used as an excellent bioindicator of environmental quality. We investigated the diversity and genetic structure of its populations along a water pollution gradient to answer the following questions: 1- Does the genetic diversity decrease under the stressful conditions of a severe water quality gradient? and 2- Is there any relationship between the haplotypes registered along the studied basin and those recorded in other distant basins? Two mitochondrial DNA markers, Cytochrome b and D-loop, were analyzed and four haplotypes were registered for both markers along the basin. H1 was present throughout all the river sections in high frequencies leading to a low genetic diversity. We suggest that only a few haplotypes tolerate the stressful conditions of mountain rivers. On the other hand, the presence of H4 at the site located downstream suggests a history of recent colonization from the southeast to the northwest of the biome. These results, together with the abundance decrease along the pollution gradient, and the non-migratory characteristic of C. decemmaculatus suggest that its populations may be at risk of local extinction., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Maternal hormones in avian egg yolks may signal and prepare offspring for the prevailing conditions. However, this adjustment requires some degree of flexibility in regulating yolk hormone deposition. The Greater Rhea (Rhea americana) has a particular mating system that combines mixed polygyny and polyandry, communal nesting, and exclusive paternal care of chicks. In this species, we previously found that yolk hormone deposition varies among eggs of different captive populations and could influence chicks' physiology and behavior. However, it is still unknown whether females can modify yolk hormone deposition in a changing social environment. Using a captive population of Greater Rheas, in this study, we quantified yolk hormone levels before and after a reduction in the number of females present in the population. We found that females deposited on average higher yolk corticosterone and lower yolk progesterone after the change in their social environment. Since corticosterone deposited into the yolk comes exclusively from the female's plasma, our results suggest that females had, on average, higher plasma corticosterone levels. The change in the number of females may increase the events of male-male competitions, courtships, and matings, leading to an increase of corticosterone in the females' plasma and then into their eggs. Since we previously found that higher yolk corticosterone and lower yolk progesterone were associated with the production of chicks that have an attenuated stress response, the present study results suggest that yolk hormone deposition is mediated by flexible mechanisms that could adjust development to the prevailing conditions., (© 2022 Wiley Periodicals LLC.)

Androgens modulate multiple key aspects of male reproduction, from morphology to mating behavior. Across animals the seasonal patterns of androgens are tightly linked to many of the species' life-history traits and their evolution. One popular framework to address this issue has been the Challenge Hypothesis, which proposed a testosterone-mediated trade-off between mating and parental care in males. Given the lack of empirical support, especially in birds, this hypothesis has been recently revisited (Challenge Hypothesis 2.0), integrating aspects such as male-female interactions and the diversity of reproductive systems in birds. Ratites constitute the most basal avian group (Palaeognathae: ratites together with Tinamiformes) and have certain characteristics that make them unique. They are flightless and generally have promiscuous mating systems with communal nests and male-only parental care (nest building, incubation and chick rearing). Furthermore, male testosterone concentrations remain high during the entire parental care period. Here we review the reproductive biology of ratites, integrating information on seasonal variations in parental care, social interactions and androgen levels across the group, in light of the Challenge Hypotheses and the Challenge Hypothesis 2.0 (there are no seasonal hormonal data for Tinamiformes, therefore they are not included in this review). We also discuss the constraints that could explain the lack of experimental approaches in behavioral endocrinology across ratites. I hope this review will motivate further research on this basal group of birds and further our understanding of the evolution of the mechanisms in the endocrine system that underly reproductive behavior across birds., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Beyond providing critical information to biologists, species distributions are useful for naturalists, curious citizens, and applied disciplines including conservation planning and medical intervention. Venomous snakes are one group that highlight the importance of having accurate information given their cosmopolitan distribution and medical significance. Envenomation by snakebite is considered a neglected tropical disease by the World Health Organization and venomous snake distributions are used to assess vulnerability to snakebite based on species occurrence and antivenom/healthcare accessibility. However, recent studies highlighted the need for updated fine-scale distributions of venomous snakes. Pitvipers (Viperidae: Crotalinae) are responsible for >98% of snakebites in the New World. Therefore, to begin to address the need for updated fine-scale distributions, we created VenomMaps, a database and web application containing updated distribution maps and species distribution models for all species of New World pitvipers. With these distributions, biologists can better understand the biogeography and conservation status of this group, researchers can better assess vulnerability to snakebite, and medical professionals can easily discern species found in their area., (© 2022. The Author(s).)

Each species and sex can develop different reproductive strategies to optimize their fitness while assigning reproductive effort. Allocosa senex is a sex-role reversed spider whose males construct long burrows in the sand. They wait for wandering females to approach, assess their sexual partners and donate their constructions to females after copulation. Females stay in the burrow and lay their egg-sac. When offspring are ready for dispersion, females leave the burrow and gain access to new mating opportunities. Males are choosy during mate courtship, preferring to mate with virgin females over copulated ones, which can even be cannibalized if males reject them. This situation turns new mating opportunities dangerous for copulated females. We wondered whether a copulated female inside the previous mate's burrow responds to courtship from a new male and if this new male can copulate, avoiding burrow construction costs. We also explored whether courtship and copulation behaviors during the first sexual encounter affected the probability of occurrence of a second copulation. For that purposes we exposed copulated females inside male burrows to new males (non-donor males). Males could locate and court females inside the previous male's burrow, and females accepted a second copulation. Hence, A. senex females are not monogamous as was expected but increase their reproductive success by copulating with non-donor males. Also, males can develop opportunistic tactics, suggesting a more dynamic mating system for this sex-role reversed spider than assumed., (© 2022. The Author(s).)

Infection may cause some insects to increase their body temperature to deal against pathogens successfully. However, one unclear aspect is whether females may use male temperature to discriminate sick from healthy partners. We tested this by using Tenebrio molitor beetles whose females use the intensity of male antennal and leg stroking that take place during mating, to discriminate among partners. We predicted that females will not choose males that are too hot and/or will penalize these male partners in terms of a reduced egg number and hatching success. We manipulated males by infecting them with an entomopathogenic fungus, and exposed these males versus control males to females. Infected and non-infected males increased their temperature during copulation but females did not choose on the basis of male's temperature or infection status. However, females laid fewer eggs and/or had a reduced hatching success after mating with infected males that had a body temperature higher than ca. 24 °C. We postulate that male temperature is another source of information involved in postcopulatory mate choice that, along with courtship traits, compose a multimodal signaling system., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Knowing the state of the art on research related to post-mining active revegetation can help to improve revegetation success and identify research gaps. We performed a systematic review about active revegetation after mining and identified 203 relevant studies. Most studies were performed in the USA (34%), in regions with a temperate climate (59%) and in abandoned coal mines (45%). The studies were focused on the plantation of woody species (59%) or sowing of herbaceous species (39%). The most widely evaluated treatments were the addition of amendments (24%) and fertilizers (21%), mainly with positive and neutral effects; in general, organic amendments presented more positive effects than inorganic amendments and fertilizers. We also identified studies on the effects of plowing, inoculation of microorganisms, nurse plants, herbivore exclusion and watering. The results of these treatments should be taken with caution, because they can vary according to the functional strategies of the introduced species and the local context, such as the degree of nutrient limitation in the mining area and abiotic conditions. Further research is needed in non-temperate climates, involving long-term monitoring and with detailed descriptions of the interventions to better interpret results and general implications of active revegetation of mining areas., Competing Interests: The authors declare no conflict of interest., (© 2022 The Author(s).)

Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) is the vector of multiple arboviruses. To evaluate the association between environmental factors and the oviposition activity of Ae. aegypti in Argentina, data on the presence and abundance of eggs were collected using ovitraps, between September of 2018 and May of 2019, in the cities of Villa María, Río Cuarto and Salsipuedes (Córdoba province, Argentina). We analysed the relationships between oviposition and five environmental factors: Temperature, precipitation, vegetation cover, human population density and distance to sites with a potential high density of larval habitats, like cemeteries and trash dumps. Environmental factors' data were collected using satellite image products. The oviposition activity was randomly distributed in three cities. Using generalized linear mixed models, we show that the house where each ovitrap was placed was a source of variability in oviposition, suggesting the relevance of microsite factors and the importance of domestic control actions. Ae. aegypti oviposition was positively correlated with night-time temperature of the previous 3 weeks, and in a context-dependent manner, it was positively correlated with human population density, vegetation cover and precipitation. The consistency and magnitude of these relationships varied between cities, indicating that oviposition is related to a complex system of environmental variables., (© 2021 Royal Entomological Society.)

This study describes the occurrence of anthropogenic microfibres (AMFs) found in sediment trap samples collected at 25 m water depth in an Antarctic fjord (Potter Cove, King George/25 de Mayo Island) from 2012 to 2015. During visual sorting of samples, AMFs were detected and described, and a subset was confirmed, via FTIR (Fourier transform infrared) spectroscopy, as semi-synthetic cellulosic and polyacrylonitrile polymers. Estimated flux of AMF varied from 115 to 152,750 microfibres m -2 throughout the studied period, with sizes ranging from 10 to 450 μm in length. Maximum AMFs fluxes occurred in summer months. Sediment traps allowed detecting temporal patterns of small (μm) AMFs, usually undersampled with nets or sieves, providing a new insight into microplastic pollution in Antarctica and its relation to environmental conditions., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Parallel phenotypic divergence is the independent differentiation between phenotypes of the same lineage or species occupying ecologically similar environments in different populations. We tested in the Antarctic limpet Nacella concinna the extent of parallel morphological divergence in littoral and sublittoral ecotypes throughout its distribution range. These ecotypes differ in morphological, behavioural and physiological characteristics. We studied the lateral and dorsal outlines of shells and the genetic variation of the mitochondrial gene Cytochrome Oxidase subunit I from both ecotypes in 17 sample sites along more than 2,000 km. The genetic data indicate that both ecotypes belong to a single evolutionary lineage. The magnitude and direction of phenotypic variation differ between ecotypes across sample sites; completely parallel ecotype-pairs (i.e., they diverge in the same magnitude and in the same direction) were detected in 84.85% of lateral and 65.15% in dorsal view comparisons. Besides, specific traits (relative shell height, position of shell apex, and elliptical/pear-shape outline variation) showed high parallelism. We observed weak morphological covariation between the two shape shell views, indicating that distinct evolutionary forces and environmental pressures could be acting on this limpet shell shape. Our results demonstrate there is a strong parallel morphological divergence pattern in N. concinna along its distribution, making this Antarctic species a suitable model for the study of different evolutionary forces shaping the shell evolution of this limpet., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Tortoises of the genus Gopherus evolved in North America and have survived major environmental challenges in the past 40 million years. However, this genus now faces multiple anthropogenic threats, such as the introduction of invasive plant species. Buffelgrass (Cenchrus ciliaris) is considered one of the greatest threats to arid and tropical ecosystems, where gopher tortoises inhabit, because the grass displaces native flora and fauna. Modification of the environment as a result of this invasive plant portends an alteration of the available thermal landscape. The aim of this paper is twofold: 1) to evaluate the thermal quality of the primary habitat of Gopherus evgoodei (tropical deciduous forest [TDF], and 2) determine the potential thermal changes due to habitat modification by buffelgrass. First, we obtained data on body temperature of active tortoises in semi-captivity. Second, we measured the operative environmental temperature during 5 years at three sites south of Sonora, Mexico that support G. evgoodei: a) a pristine TDF (Conserved-TDF); b) a forest patch surrounded by introduced buffelgrass pasture (Partial-TDF); and c) an introduced buffelgrass pasture area (Buffel-Pasture). Our results demonstrate that the intact microhabitats within the TDF provide G. evgoodei with high thermal quality at both spatial and temporal scales. However modified habitat by buffelgrass had higher operative temperatures for G. evgoodei than TDF. The thermal quality of the sites disturbed with buffelgrass can exceed the thermal requirements of G. evgoodei by up to 25 °C. Finally, we discussed potential collateral effects of habitat modification by invasion by buffelgrass., (Copyright © 2022 Elsevier Ltd. All rights reserved.)