Southern Region Of South America Research Articles

Biodiversity and Wetting of Climate Alleviate Vegetation Vulnerability Under Compound Drought‐Hot Extremes

AbstractGlobal warming has intensified the intensity of compound drought‐hot extremes (CDHEs), posing more severe impacts on human societies and ecosystems than individual extremes. The vulnerability of global terrestrial ecosystems under CDHEs, along with its key influencing factors, remains poorly understood. Based on multiple remote sensing data, we construct a Vine Copula model to appraise vegetation vulnerability under CDHEs, and attribute it to climatic and biotic factors for five different vegetation types. High vulnerability is detected in central and southern regions of North America, eastern and southern regions of South America, Southern Africa, northern and western Europe, and northern and eastern Australia. The drier the climate, the higher will be the vulnerability. Furthermore, biodiversity and biomass are key biotic factors influencing the vulnerability of various vegetation types, such that ecosystems with richer biodiversity and higher biomass have lower vulnerability to CDHEs. The findings deepen understanding of terrestrial ecosystem response to CDHEs.

Spatial and Temporal Characteristic Analysis and Risk Assessment of Global Highly Pathogenic Avian Influenza H5N8 Subtype

H5N8 HPAI is a highly infectious avian disease that now poses a serious threat and potential risk to poultry farming, wild birds, and public health. In this study, to investigate the seasonality and transmission directionality of global H5N8 HPAI, the spatial and temporal analysis of H5N8 HPAI was conducted using time series decomposition and directional distribution analysis. An ecological niche model was developed for H5N8 HPAI in poultry to identify areas at high risk of H5N8 HPAI in poultry and associated risk factors. The results indicated that three global pandemics of H5N8 HPAI emerged from 2014 to 2022, all showing a southeast–northwest distribution direction. H5N8 HPAI occurred more frequently in winter and less frequently in summer. The southwestern border region and the southeastern region of North America, the southern region of South America, most of Europe, the southern border region and the northern border region of Africa, and the southwestern region and the southeastern region of Asia provide the suitable environment for the occurrence of H5N8 HPAI in poultry. Chicken density, duck density, population density, bio1 (annual mean temperature), and land cover were considered important variables for the occurrence of H5N8 HPAI in poultry. This study can help optimize the use of resources and provide new information for policymakers to carry out prevention and control efforts.

Validation of qPCR reference genes in the endangered annual killifish Austrolebias charrua considering different tissues, gender and environmental conditions.

The annual killifish Austrolebias charrua is an endangered species, endemic to the southern region of South America, which inhabits temporary ponds that emerges in the rainy season. The main anthropogenic threat driving the extinction of A. charrua stems from extensive agriculture, primarily due to the widrespread use of glyphosate-based herbicides near their habitats. Annual killifishes have been used as models for ecotoxicological studies but, up to now, there are no studies about reference genes in any Austrolebias species. This represents an obstacle to the use of qPCR-based technologies, the standard method for gene expression quantification. The present study aimed to select and validate potential reference genes for qPCR normalization in the annual killifish Austrolebias charrua considering different tissues, gender and environmental conditions. The candidate reference genes 18 s, actb, gapdh, ef1a, shox, eif3g, and the control gene atp1a1 were evaluated in male and female individuals in three different tissues (brain, liver, and gills) under two experimental conditions (control and acute exposition to Roundup Transorb®). The collected tissues were submitted to RNA extraction, followed by cDNA synthesis, cloning, sequencing, and qPCR. Overall, 18 s was the most stable reference gene, and 18 s and ef1a were the most stable combination. Otherwise, considering all variables, gapdh and shox were the least stable candidate genes. Foremost, suitable reference genes were validated in A. charrua, facilitating accurate mRNA quantification in this species, which might be useful for developing molecular tools of ecotoxicological assessment based on gene expression analysis for environmental monitoring of annual killifish.

Infectious clones of cotton leafroll dwarf virus strains used for genotype evaluation in cotton

AbstractCotton blue disease (CBD) and atypical‐CBD are the most important viral diseases of cotton plants in the southern region of South America. Common and atypical strains of cotton leafroll dwarf virus (CLRDV and CLRDV‐at, respectively) are thought to be causative agents of CBD and atypical‐CBD, respectively. Inoculation of test plants via aphid vectors is difficult, as is determining strains via molecular diagnosis; accordingly, it is difficult for breeders to evaluate the effects of blue disease‐associated virus infections in cotton lineages. In the present study, we attempted to circumvent these difficulties by producing six full‐length cDNA infectious clones from CLRDV and CLRDV‐at strains using the Gibson Assembly protocol. For inoculation of the infectious clones, a vacuum chamber‐mediated agroinfiltration protocol was adapted and applied. Using this protocol, 90%–100% of cotton plants became infected with the clones, which was not possible via syringe‐based agroinfiltration. A genotyping protocol based on RT‐qPCR targeting a specific region of the virus P0 protein was also developed, allowing rapid differentiation of CLRDV and CLRDV‐at. Applying this protocol to 68 field samples revealed that CLRDV‐at was dominant (50%) over CLRDV (5.8%) in single virus infections. These preliminary results imply that CLRDV‐at might occupy the ecological niche of CLRDV in the cotton fields of Brazil.

Highly Efficient Water-Based Extraction of Biliprotein R-Phycoerythrin From Marine the Red-Macroalga Sarcopeltis skottsbergii by Ultrasound and High-Pressure Homogenization Methods

Sarcopeltis skottsbergii is an endemic species of the southern region of South America, with R-phycoerythrin (R-PE) as an accessory photosynthetic pigment. The production of S. skottsbergii is around twenty thousand tons of dry alga per year. The evaluation of (R-PE) in a biorefinery model is still incipient in the algal biotechnology area and will be used in the food, pharmaceutical, cosmeceutical, and nutraceutical industries. This work evaluated the cell disruption and separation processes by using two green technologies, ultrasound-assisted extraction (UAE) and high-pressure homogenization (HPH), to obtain an R-phycoerythrin enriched extract from S. skottsbergii. Two-levels three-factor central composite design (CCD) and response surface methodology (RSM) were carried out to optimize the extraction conditions, including the factors for UAE (time, amplitude, and solvent) and HPH (Pressure, number of passes, and solvent). Additionally, a second-order polynomial fit was performed to fit the experimental data by the green method. HPH method was the most efficient extraction method under the conditions obtained of 100-400 MPa pressure power, 2-3 number of passes, and distilled water as solvent. Furthermore, the experimental extraction yields ranged from 4.4-5.7 mg of PE g-1 of dry biomass under the optimal extraction conditions (400 MPa; 2 passes), which agreed with the predictive yield of 4.6-5.5 mg g-1 DW. The ultrafiltration membrane used for the separation process for both methods exhibited a rejection of R-phycoerythrin concentrated at 30 KDa. Furthermore, R-phycoerythrin showed a positive correlation between the antioxidant capacity (ORAC) in the best-selected extractions. After the extraction, the same pattern was observed in Chlorophyll a and total carotenoids with DPPH. Thus, it was an attractive non-aggressive extraction alternative with biological activity of interest for formulating biotechnological products for the food industry is suggested.

Factors associated with genetic damage - an analysis integrating human populations from Southern Brazil.

Socioeconomic and demographic factors, lifestyle and cultural characteristics may play an important role in the development of genetic damage. This damage represents a potential health risk to an individual and increases the risk of developing negative outcomes. The aim of this study was to investigate the association of a set of factors and genetic damage by gathering data from previously studied populations in southern Brazil. This study analyzed data related to genetic damage and socioeconomic, demographic, and lifestyle variables of 514 individuals aged 18 to 64years, residing in 8 cities located in the extreme south of the Brazil. A total of twelve factors were considered in the analysis, and of these seven had some association with the frequency of micronucleus or some parameter of the comet assay. Interestingly, age was a factor weakly associated with genetic damage, while skin color, occupational exposure, drug use, exposure to radiation, and the cultural habit of consuming chimarrão were shown to be associated with genetic damage when analyzed using multivariate regression. Therefore, we suggest that yerba mate consumption is a confounding factor and should be considered in cytogenetic studies in the southern region of South America. These results reinforce the need for human biomonitoring studies to include consideration of a broad range of population and cultural characteristics when seeking to identify relevant associations.

Spatial and Temporal Global Patterns of Drought Propagation

Drought is the most expensive natural hazard and one of the deadliest. While drought propagation through standardised indices has been extensively studied at the regional scale, global scale drought propagation, and particularly quantifying the space and time variability, is still a challenging task. Quantifying the space time variability is crucial to understand how droughts have changed globally in order to cope with their impacts. In particular, better understanding of the propagation of drought through the climate, vegetation and hydrological subsystems can improve decision making and preparedness. This study maps spatial temporal drought propagation through different subsystems at the global scale over the last decades. The standardised precipitation index (SPI) based on the gamma distribution, the standardised precipitation evapotranspiration index (SPEI) based on the log-logistic distribution, the standardised vegetation index (SVI) based on z-scores, and the standardised runoff index (SRI) based on empirical runoff probabilities were quantified. Additionally, drought characteristics, including duration, severity and intensity were estimated. Propagation combined the delay in response in the subsystems using drought characteristics, and trends in time were analysed. All these were calculated at 0.05 to 0.25 arc degree pixels. In general, drought propagates rapidly to the response in runoff and streamflow, and a with longer delay in the vegetation. However, this response varies spatially across the globe and depending on the observation scale, and amplifies progressively in duration and severity across large regions from the meteorological to the agricultural/ecological and hydrologic subsystems, while attenuating in intensity. Significant differences exist between major Köppen climate groups in drought characteristics and propagation. Patterns show intensification of drought severity and propagation affecting vegetation and hydrology in regions of southern South America, Australia, and South West Africa.

Emergent trophic interactions following the Chinook salmon invasion of Patagonia

AbstractIn their native range, Pacific salmon (Oncorhynchus spp.) have strong interactions with a multitude of species due to the annual pulse of marine‐derived nutrients that they deliver to streams and forests when they spawn and die. Over the past few decades, Chinook salmon (Oncorhynchus tshawytscha) has established non‐native populations throughout the Patagonia region of southern South America. Here, we provide the first assessment of the pathways through which salmon‐derived nutrients enter stream and forest food webs in Patagonia by surveying multiple streams in southern Chile to identify invertebrate and vertebrate consumers of salmon carcasses and summarizing all documented trophic interactions of Chinook salmon in Patagonia. Blowflies (Calliphoridae) were the dominant colonizer of carcasses in the riparian zone, and midge flies (Chironomidae) were the most common invertebrate on submerged carcasses. Camera trap monitoring in the riparian zone revealed consumption of carcasses or carcass‐associated invertebrates by the insectivorous passerine bird “chucao” (Scelorchilis rubecula), small rodents (black rat Rattus rattus, house mouse Mus musculus, and/or colilargo Oligoryzomys longicaudatus), the South American fox “culpeo” (Lycalopex culpaeus), and the invasive American mink (Neovison vison). A mink was filmed transferring a carcass from stream to streambank, indicating that vertebrate scavenging likely increases the degree to which marine‐derived nutrients enter terrestrial food webs. The native taxa that consume salmon are closely related to species that benefit from salmon consumption in North America, suggesting that the pathways of salmon nutrient incorporation in North American food webs have functionally re‐emerged in South America. Similarly, non‐native trout (Oncorhynchus mykiss and Salmo trutta) and mink consume salmon in Patagonia, and their eco‐evolutionary history of coexistence with salmon could mean that they are preadapted for salmon consumption and could thus be key beneficiaries of this invasion. Expanded monitoring of the abundance and impacts of salmon will be vital for understanding how these novel inputs of marine‐derived nutrients alter Patagonian food webs.

CLOROFILA EXTRAÍDA DE RESÍDUO INDUSTRIAL DA ERVA-MATE (Ilex paraguaiensis) UMA POSSIBILIDADE DE ECONOMIA CIRCULAR

CHLOROPHYLL EXTRACTED FROM INDUSTRIAL WASTE FROM MATE-HERB (Ilex paraguaiensis) A POSSIBILITY OF CIRCULAR ECONOMY. Chlorophyll is the most abundant green pigment on the planet, it is unstable and decomposes naturally. Mate-herb is a traditional native plant in the southern region of South America, and its tea is part of the local culture and extractive agriculture. The mate-herb industry generates as a by-product a resinous material rich in chlorophyll whose use is proposed to be a natural pigment. The chlorophyll extraction method uses ethanol as a solvent; its structural modification leads to the obtainment of derivatives like pheophytin, Co-pheophytin, Ni-pheophytin, and Zn-pheophytin. The samples were analyzed by electronic (VISIBLE) and vibrational (FTIR) spectroscopy, and energy-dispersive X-ray fluorescence spectrometry (EDXRF). Color analysis (CIE L*a*b*) was performed by decomposition in grayscale and the classification of the samples by the supervised machine learning (ML) algorithm Random Forest (RF), showing adequate accuracy for this type of matrix. The pigments were dispersed in synthetic enamel paint to study color stability when exposed to lighting. It was verified that Co-pheophytin and Ni-pheophytin are the most stable. The chlorophyll extracted from the resin presents an economically viable use for residues from mate-herb industries, whose family farmers benefit, with the bias of environmental and social sustainability, within the circular economy.

Lessons of 15,000 Years of Human–Wildlife Interaction for Conservation in Patagonia in the 21st Century

Humans arrived in the Patagonia region of southern South America in the late Pleistocene period, ca. 15,000 years ago. A few centuries later, during a period of rapid warming, the megafauna went extinct in Patagonia, as well as some smaller species, like the guanaco (Lama guanicoe), in the southern portion of the region. As in other regions, extinctions probably occurred due to a combination of effects of climate and direct and indirect impacts of humans on wildlife communities. We reviewed recent archeological and genetic-based discoveries about numbers and distributions of humans and wildlife and their early interactions and used them to draw lessons for current debates among managers and scientists. Recent discoveries, for example, help us understand (1) the population limitation mechanisms and other interactions involving guanacos, livestock, forage, predators, and scavengers; (2) the magnitude of wildlife movements and the need for landscape-level planning for conservation; (3) the importance of indirect effects of human activities on wildlife communities; and (4) the compounded effects of human activities and climate change on wildlife. We believe these lessons drawn from deep time and recent history can help define new priorities for research and management and inform our conservation vision for the 21st century, a period when dramatic climate change impacts will add challenges to a region subject to a century of overgrazing and other anthropogenic pressures.

Attribution and projections of temperature extreme trends in South America based on CMIP5 models.

Temperature extreme indices were analyzed for five continental regions of southern South America defined according to their climatic characteristics. Gridded observations, reanalysis, and global-coupled climate models from CMIP5 were used with the approach of temperature extreme trend attribution analysis on fixed-threshold and percentile-based temperature extremes indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). The largest positive trends are exhibited in the tropical nights index, and a clear anthropogenic signal is evident in the subtropical region. In the subtropical central Andes, there is a decrease in the frost days index and increases in the tropical nights and summer days indices, and an anthropogenic signal is evident. In the Patagonian region, all trends from the historical runs were significant, while the ones from the natural experiment were nonsignificant, showing the marked effect of anthropogenic forcing in this region in the extreme temperature events. Projected changes in extreme indices for the 21st century are consistent with a warming climate, and larger changes are expected in the warm nights index.

Endemic and Other Dimorphic Mycoses in The Americas.

Endemic fungi are thermally dimorphic fungi that have a limited geographic range and can cause both primary disease and opportunistic infections. The Americas are home to more genera of endemic fungi than anywhere else on earth. These include Coccidioides, Histoplasma, Blastomyces, Paracoccidioides, and Sporothrix. Endemic fungi are found across the Americas and the Caribbean, from Blastomyces gilchristi, which extends into the northeast corners of North America, to Histoplasma capsulatum, which occurs all the way down in the southern regions of South America and into the Caribbean Islands. Symptoms of endemic fungal infection, when present, mimic those of many other diseases and are often diagnosed only after initial treatment for a bacterial or viral disease has failed. Endemic fungi place a significant medical burden on the populations they affect, especially in immunocompromised individuals and in resource-limited settings. This review summarizes the ecology, geographical range, epidemiology, and disease forms of the endemic fungi found in the Americas. An emphasis is placed on new and proposed taxonomic changes, including the assignment of new species names in Histoplasma, Blastomyces, and Paracoccidioides.

Non‐native Chinook salmon add nutrient subsidies and functional novelty to Patagonian streams

Abstract The impacts of non‐native species are hypothesised to be proportional to the functional distinctiveness of invaders in their invaded ecosystems. Throughout the Patagonia region of southern South America, Chinook salmon (Oncorhynchus tshawytscha) have recently established non‐native populations, and their anadromous, semelparous life cycle could be functionally unique such that marine‐derived nutrients are delivered to streams which have historically lacked such a resource linkage with the ocean. We tested the hypothesis that salmon subsidise biofilm‐associated algae in streams throughout the Aysén province of southern Chile. Using spatial and temporal variation in the presence of salmon among multiple streams and across two spawning seasons, we found strong evidence of salmon‐subsidised algae in three out of four streams examined that have spawning salmon populations. The biofilm of subsidised streams had enriched stable isotopic ratios of nitrogen and carbon, indicating that marine‐derived nutrients were incorporated by biofilms. This nutrient uptake translated into increased algal biomass and percent of total biofilm biomass composed of algae, indicating that the incorporation of marine‐derived nutrients stimulated autotrophic production of biomass. In one stream, the incorporation of marine‐derived nutrients by biofilm occurred in only one of the two studied spawning seasons. Incorporation occurred in a year with low flows of water throughout salmon spawning (4.59 m3/s) and did not occur in a year with much higher flows (41.6 m3/s), suggesting that inter‐annual variation in discharge can mediate the subsidising effect of salmon. These results indicate that Chinook salmon have bridged the historical gap between productive marine ecosystems and nutrient‐poor stream ecosystems in Patagonia. Anadromous salmon can be a significant source of nutrients in nutrient‐limited catchments, and their ongoing expansion in southern South America is likely to entail ecological impacts in stream and riparian food webs.

Living in the shadows: Diversity of amphibians, reptiles and birds in shade‐grown yerba mate (Ilex paraguariensis) plantations

AbstractNative Ilex paraguariensis (yerba mate) is one of the most widespread crops in the Atlantic Forest region of southern South America and has an important economic and cultural value in Paraguay, Argentina, Brazil and Uruguay. Despite the known potential of shade‐grown products (especially cocoa and coffee) to protect biodiversity, the benefits of shade‐grown yerba mate for biodiversity conservation in the Atlantic Forest remain scarce, one of the most threatened ecoregions in the world, also considered a biodiversity hotspot. In order to understand these potential benefits, it is important to identify how species use shade‐grown yerba mate plantations, as well as if it can be an strategy to improve or maintain biodiversity in complex socio‐ecological landscapes. We analysed the potential benefits of forests with shade‐grown yerba mate for birds, amphibian and reptiles in the Reserve for National Park ‘San Rafael’ and its buffer area (Itapúa Department, Paraguay). We evaluated differences in species richness and composition between three environments: forest with shade‐grown yerba mate, forest edge and monoculture crop plantations analysing beta diversity. A total of 112 bird species were recorded in all three environments. Regarding the herpetological community, we recorded 10 species (seven amphibians and three reptiles). Our results indicate that forests with yerba mate plantations not only maintains the bird species richness, but also its species composition differs significantly from edge and croplands, which might be an indicator of the contribution of shade‐grown yerba mate plantations to conservation. The results of the research would help to value the impact of sustainable agroforestry activities for the conservation of Atlantic Forest biodiversity.Abstract in Spanish is available with online material.

High levels of endemism and local differentiation in the fungal and algal symbionts of saxicolous lecideoid lichens along a latitudinal gradient in southern South America.

Saxicolous, lecideoid lichenized fungi have a cosmopolitan distribution but, being mostly cold adapted, are especially abundant in polar and high-mountain regions. To date, little is known of their origin or the extent of their trans-equatorial dispersal. Several mycobiont genera and species are thought to be restricted to either the Northern or the Southern Hemisphere, whereas others are thought to be widely distributed and occur in both hemispheres. However, these assumptions often rely on morphological analyses and lack supporting molecular genetic data. Also unknown is the extent of regional differentiation in the southern polar regions. An extensive set of lecideoid lichens (185 samples) was collected along a latitudinal gradient at the southern end of South America. Subantarctic climate conditions were maintained by increasing the elevation of the collecting sites with decreasing latitude. The investigated specimens were placed in a global context by including Antarctic and cosmopolitan sequences from other studies. For each symbiont three markers were used to identify intraspecific variation (mycobiont: ITS, mtSSU, RPB1; photobiont: ITS, psbJ-L, COX2). For the mycobiont, the saxicolous genera Lecidea, Porpidia, Poeltidea and Lecidella were phylogenetically re-evaluated, along with their photobionts Asterochloris and Trebouxia. For several globally distributed species groups, the results show geographically highly differentiated subclades, classified as operational taxonomical units (OTUs), which were assigned to the different regions of southern South America (sSA). Furthermore, several small endemic and well-supported clades apparently restricted to sSA were detected at the species level for both symbionts.

Making visible the invisible. A microarchaeology approach and an Archaeology of Color perspective for rock art paintings from the southern cone of South America

From the literature research review of studies that involved the physicochemical characterization of rock art paintings in Argentina and Chile, we evaluate the impact of this analytic approach in our understanding of these visual and material practices in the southern region of South America. We identify the techniques, protocols and sample preparation, the information obtained, and archaeological questions addressed with these analyses. Consequently, we propose the need for a microarchaeological approach. We stress the materiality and particularities of the rock art practice, as an action performed over continuously altered walls, which forms complex microstratigraphies. Moreover, we highlight the benefits of obtaining comparable results with the use of paintings on different supports and contexts to hold an Archaeology of Color that allows studying not only the meaning, but also understand the exploitation, production, and consumption of color, being the painted rock art one form of the final stage of a complex sequence related to color materials.

The experimental butchering of coypu (Myocastor coypus): Implications for the analysis of the archaeofaunal record

Coypu (Myocastor coypus) is a medium-small sized rodent which was exploited during the Late Holocene in the Humid Pampas and other regions of southern South America. Therefore, this paper aims to broaden our knowledge about archaeofaunal assemblages using data collected from five events of experimental butchery. These events were carried out by nutrieros (coypu hunters) and hunters from Buenos Aires province (Argentina) and were directed towards the extraction of some consumable resources from the carcass: hide and meat. Butchers used experimental flakes and tools made from ortoquartzite of the Sierras Bayas Group. The butchering process involved different tasks on the carcasses such as skinning, evisceration, disarticulation, and cutting into small pieces. We controlled the time involved in each experimental event and registered the weights of different byproducts. Resulting cut marks and fractures located on cranial and postcranial bones were associated with skinning, dismemberment, and segmentation for cooking. From this kind of actualistic study, we emphasized the significance of butcher’s skill to process small mammals and its consequences as resulting marks. In addition, we gathered information about the potential of exploitation of the prey in the present. Moreover, our study supports some interpretations made upon the archaeological record, questions others and alerts about equifinality.

The enigmatic Leiosaurae clade: Phylogeography, species delimitation, phylogeny and historical biogeography of its southernmost species

The clade Leiosaurae is composed of poorly-known species endemic to the southern region of South America. The difficulties of finding these lizards in the field, and their highly conserved morphology, have limited our taxonomic knowledge and understanding of their evolutionary histories. Here, we use data collected over 9 years to study the phylogenetic history, genetic diversity, and biogeographic history of almost all the southernmost species of Leiosaurae (except P. nigroigulus), including: Leiosaurus bellii, Diplolaemus darwinii, D. bibronii, D. sexcinctus and D. leopardinus. We use a fragment of the mitochondrial cytochrome-b gene to resolve general phylogeographic patterns, and add another mitochondrial gene and eight nuclear genes to perform species delimitation and phylogenetic analyses associated with divergence times. We found evidence for three putative new species-level taxa within L. bellii and five within Diplolaemus species, indicating high levels of geographic structure. We use a time-calibrated phylogeny to estimate ranges of ancestral distributions and to generate new hypotheses about their historical biogeography.

Differential reproductive investment in females of <em>Lithodes santolla</em> (Decapoda: Anomura) from different regions of southern South America

The southern king crab Lithodes santolla experiences low temperatures and unpredictable food conditions, and is under variable fishing pressure. To compare the reproductive investment of females, crabs were captured from three sites (Beagle Channel 55°S, Tierra del Fuego Atlantic coast 52-54°S and San Jorge Gulf 45-47°S). Fecundity, water and lipid contents were measured in midgut gland, ovary and muscle. To assess the maternal investment in the offspring, egg masses were analysed on lipid, protein, water and inorganic matter contents, egg volume and embryo size. Although fecundity was similar among sites, San Jorge Gulf females showed higher water and lower lipid contents in somatic and reproductive organs. The egg mass energy reserves varied among sites, showing the highest lipid values in the Beagle Channel, and the highest protein and inorganic matter content in San Jorge Gulf. Though water content was similar, egg volume and embryo size were higher in San Jorge Gulf. Moreover, maternal size did not correlate with egg volume, embryo size or lipid, protein and inorganic matter content of the eggs. This study suggests that reproductive investment of L. santolla varies among regions exposed to different environmental conditions, such as the quality of food available, denoting a female compensatory mechanism.

Assessing cross-species transmission of hemoplasmas at the wild-domestic felid interface in Chile using genetic and landscape variables analysis

The co-occurrence of domestic cats (Felis silvestris catus) and wild felids in rural landscapes can facilitate pathogen transmission. However, in the relatively-isolated regions of southern South America there have been no comprehensive studies to assess disease transmission risks between domestic cats and forest-dwelling wild felids such as guigna (Leopardus guigna). We evaluated hemoplasma infection and the possibility of transmission between domestic cats and guignas by comparing spatial and phylogenetic patterns of pathogen prevalence. Blood/spleen samples were collected from 102 wild guignas and 262 co-occurring rural domestic cats across the entire distribution range of guigna in Chile. Hemoplasma infection was assessed by direct sequencing of the 16S RNA gene. Infection with hemoplasmas was common and geographically widespread across different bioclimatic areas for both species. The most common feline Mycoplasma species in guigna and domestic cats were Candidatus M. haemominutum (CMhm) (15.7% guigna; 10.3% domestic cat) and Mycoplasma haemofelis (Mhf) (9.8% guigna, 6.1% domestic cat). A previously undescribed Mycoplasma sp. sequence was found in two guignas and one cat. Continuous forest-landscapes were associated with higher hemoplasma-prevalence in guignas. Shared hemoplasma nucleotide sequence types between guigna and domestic cats were rare, suggesting that cross-species transmission between guignas and domestic cats may occur, but is probably uncommon. Ectoparasites, which have been linked with hemoplasma transmission, were not found on guignas and were infrequent on domestic cats. Our results suggest that transmission pathways vary among hemoplasma species and, contrary to our predictions, domestic cats did not appear to be the main driver of hemoplasma infection in guignas in these human-dominated landscapes.