Diversity of bacterial communities in wetlands of Calakmul Biosphere Reserve: a comparative analysis between conserved and semi-urbanized zones in pre-Mayan Train era.

BACKGROUND: The Calakmul Biosphere Reserve (CBR) is known for its rich animal and plant biodiversity, yet its microbial communities remain largely unknown. The reserve does not possess permanent bodies of water; nevertheless, seasonal depressions associated with fractures create wetlands, known locally as aguadas. Given the recent construction of the Maya train that crosses the CRB, it is essential to assess the biodiversity of its microorganisms and recognize their potential as a valuable source of goods. This evaluation is pivotal in mitigating potential mismanagement of the forest ecosystem. To enhance comprehension of microbial communities, we characterized the microbiota in three different wetlands. Ag-UD1 and Ag-UD2 wetlands are located in a zone without human disturbances, while the third, Ag-SU3, is in a semi-urbanized zone. Sampling was carried out over three years (2017, 2018, and 2019), enabling the monitoring of spatiotemporal variations in bacterial community diversity. The characterization of microbiome composition was conducted using 16S rRNA metabarcoding. Concurrently, the genomic potential of select samples was examined through shotgun metagenomics. RESULTS: Statistical analysis of alpha and beta diversity indices showed significant differences among the bacterial communities found in undisturbed sites Ag-UD1 and Ag-UD2 compared to Ag-SU3. However, no significant differences were observed among sites belonging to the undisturbed area. Furthermore, a comparative analysis at the zone level reveals substantial divergence among the communities, indicating that the geographic location of the samples significantly influences these patterns. The bacterial communities in the CBR wetlands predominantly consist of genera from phyla Actinobacteria, Acidobacteria, and Proteobacteria. CONCLUSION: This characterization has identified the composition of microbial communities and provided the initial overview of the metabolic capacities of the microbiomes inhabiting the aguadas across diverse conservation zones. The three sites exhibit distinct microbial compositions, suggesting that variables such as chemical composition, natural and anthropogenic disturbances, vegetation, and fauna may play a pivotal role in determining the microbial structure of the aguadas. This study establishes a foundational baseline for evaluating the impact of climatic factors and human interventions on critical environments such as wetlands.

Abundance of Leishmania (Kinetoplastida: Trypanosomatidae) vectors in Baldim, a municipality in the Espinhaço Range Biosphere Reserve in Brazil.

Leishmaniasis is a zoonoses caused by protozoan parasites belonging to the Leishmania genus that is transmitted to humans through the bite of previously infected phlebotomine sandflies (Diptera:Psychodidae:Phlebotominae). In Brazil, 2 types of leishmaniasis are endemic, tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL). In Baldim, a municipality in the Espinhaço Range Biospere Reserve (ERBR), 5 autochthonous cases of TL, and one autochthonous case of VL were reported from 2017 to 2022. Owing to the lack of data on entomological fauna, we surveyed the occurrence and distribution of phlebotomine sandflies that could act as Leishmania vectors, as well as natural Leishmania infection. During 1 year, 918 sandfly specimens belonging to 12 species were collected. The predominant species was Lutzomyia longipalpis (Lutz & Neiva, 1912) (32.0%), a proven VL agent, followed by Evandromyia evandroi (Costa Lima & Antunes, 1936) (20.7%), Evandromyia cortelezzii (Brèthes, 1923) (17.0%), Nyssomyia whitmani (Antunes & Coutinho, 1939) (12.2%), and Nyssomyia intermedia (Lutz & Neiva, 1912) (10.5%), all putative or proven TL agents. Seasonal fluctuations and endo-exophilic behavior were delineated for the main phlebotomine sandflies. The population of Lu. longipalpis was higher during the coolest and driest months, although different profiles were noted for the other species. Natural Leishmania infection was not detected in any of the 197 phlebotomine sandfly females analyzed. The results were compared with those previously obtained in other municipalities belonging to the ERBR. The presence of Leishmania vectors and human cases of leishmaniasis indicate a risk of Leishmania transmission in the region.

Risk assessment of pesticides used in the eastern Avocado Belt of Michoacan, Mexico: A survey and water monitoring approach.

Pesticides use raises concerns regarding environmental sustainability, as pesticides are closely linked to the decline of biodiversity and adverse human health outcomes. This study proposed a holistic approach for assessing the potential risks posed by pesticides for human health and the environment in the eastern region of Michoacan, where extensive agricultural lands, especially corn and avocado fields, surround the Monarch Butterfly Biosphere Reserve. We used a combination of qualitative (semi-structured interviews) and quantitative (chemical analysis) data. Fifty-five interviews with smallholder farmers allowed us to identify pesticide types, quantities, frequencies, and application methods. A robust and precise analytical method based on solid-phase extraction and LC-MS/MS was developed and validated to quantify 21 different pesticides in 16 water samples (rivers, wells, runoff areas). We assessed environmental and human health risks based on the pesticides detected in the water samples and reported in the interviews. The interviews revealed the use of 28 active ingredients, including glyphosate (29 % of respondents), imidacloprid (27 %), and benomyl (24 %). The pesticide analysis showed the presence of 13 different pesticides and degradation products in the water samples. The highest concentrations were found for imidacloprid (1195 ngL-1) and carbendazim (a degradation product of benomyl; 932 ngL-1), along with the metabolite of pyrethroid insecticides, 3-PBA (494 ngL-1). The risk assessment indicates that among the most used pesticides, the fungicide benomyl and carbendazim pose the highest risk to human health and aquatic ecosystems, respectively. This study unveils novel insights on agricultural practices for the avocado, a globally consumed crop that is undergoing rapid production expansion. It calls for the harmonisation of crop protection with environmental responsibility, safeguarding the health of the people involved and the surrounding ecosystems.

Community structure of raptors in the páramo landscape of the Ecuadorian Andes

Introduction: Habitat alterations result in biodiversity loss, particularly in regions with high levels of diversity and endemism. Raptors are an essential part of the functionality and stability of ecosystems and indicators of habitat quality. In the paramo grassland ecosystems in the high Andes of Northern South America, raptors contain a high concentration of threatened species. Objective: To describe the raptor community structure and determine the species associations. Methods: We made monthly raptor counts in eight transects from October 2021 to September 2022 and used a principal component analysis to determine species associations. Results: We identified 149 individuals (seven species, three families) in two communities: abundant (Carunculated Caracara, Variable Hawk, Andean Condor and Turkey Vulture; PCI = 47 %), and scarce (Cinereous Harrier, Peregrine Falcon and Aplomado Falco; PCII = 27 %). Conclusion: We provide a valid description and understanding of raptor community structure, identifying two communities and the dynamics between them. The first is characterized by an increased abundance of generalist and regionally common species, when the abundance of these species decreases, the second community is defined, characterized by an increase in the abundance of specialist and rare species at the local scale.

Introducción: Las alteraciones del hábitat provocan la pérdida de biodiversidad, especialmente en regiones con altos niveles de diversidad y endemismo. Las aves rapaces son una parte esencial de la funcionalidad y estabilidad de los ecosistemas, y son indicadores de la calidad del hábitat. En los ecosistemas de páramo en los Andes del norte de Sudamérica, hay una concentración de especies rapaces amenazadas. Objetivo: Describir la estructura de la comunidad de aves rapaces y determinar las asociaciones entre las especies. Métodos: Hicimos conteos mensuales de rapaces en ocho transectos, de octubre 2021 a setiembre 2022 y usamos un análisis de componentes principales para determinar las asociaciones entre especies. Resultados: Identificamos 149 individuos (siete especies, tres familias) en dos comunidades: abundantes (e.g., Caracara Curiquingue, Gavilán Variable, Cóndor Andino y Gallinazo Cabecirrojo; PCI = 47 %), y poco abundantes (e.g., Caracara Curiquingue, Gavilán Variable, Cóndor Andino y Gallinazo Cabecirrojo; PCII = 27 %). Conclusiones: Nuestro enfoque proporciona una descripción y comprensión válida de la estructura de la comunidad de rapaces. Identificamos dos comunidades y la dinámica entre ellas. La primera se caracteriza por una mayor abundancia de especies generalistas y regionalmente comunes, cuando la abundancia de estas especies disminuye, se define la segunda comunidad, caracterizada por un aumento de la abundancia de especies especialistas y raras a escala local.

Coral reef degradation at an atoll of the Western Colombian Caribbean.

Coral reef decline is an issue of concern around the globe. Remote and uninhabited coral areas are not exempt from facing changes in species composition and functionality due to global drivers. Quitasueño is a remote atoll within the Seaflower Biosphere Reserve, in the Southwestern Caribbean Sea. To evaluate the current status of the coral reefs in Quitasueño we sampled 120 stations through Rapid Ecological Assessment and evaluated four stations through Planar Point Intercept to compare the current percent cover of benthic groups with previous studies in the area. We found pronounced changes in coral and macroalgae covers in time, and great conspicuousness of multiple conditions of deterioration along Quitasueño, including diseases, coral predation, and aggression and invasion of coral colonies by macroalgae and sponges. The reef ecosystem seems to be facing a phase shift, in which the benthic cover previously dominated by hard corals is currently dominated by fleshy macroalgae. It is essential to evaluate the possible drivers of the extent of degradation of Quitasueño to understand the process of deterioration and mitigate the impacts.

Arthropod diversity in phytotelmata of Calathea capitata (Zingiberales; Marantaceae) host plants from Peru

Cryptic habitats are often overlooked in biodiversity surveys. Phytotelmata, or plant pools, are one type of cryptic habitat that supports diverse fauna in a miniature ecosystem. This study surveys the arthropod community of two types of phytotelmata, bracts and leaf rolls, on a single species, Calathea capitata (Ruiz and Pav.) Lindl. (Zingiberales: Marantaceae), from one Amazon site in Peru. Specimens were collected from eight bracts and eight leaf rolls. A total of 55 arthropods (36 adults, 19 juveniles) were found in both phytotelmata types. In the bract samples were found: spiders (Araneae: Corinnidae), beetles (Coleoptera: Carabidae, Erotylidae, Staphylindae), flies (Diptera: Limoniidae), a leafhopper nymph (Hemiptera: Cicadellidae), ants (Hymenoptera: Formicidae), and unidentified larvae. In leaf roll samples were found: Leaf beetles (Coleoptera: Chrysomelidae), an earwig (Dermaptera: Spongiforidae), flies (Diptera: Drosophilidae), and an adult leafhopper (Hemiptera: Cicadellidae). A similar survey of Calathea lutea Schultes in Peru revealed a community dominated by Coleoptera in leaf rolls and Diptera in bracts, with a few Dermaptera and Hymenoptera, but no Araneae or Hemiptera. This study demonstrates that phytotelmata host diverse taxa and serve as a nursery to immature stages thus impacting the life cycles of local fauna, which in turn affect local biodiversity.

Los hábitats crípticos a menudo son ignorados en los estudios de biodiversidad. fitotelmata, o piscinas de plantas, son un tipo de hábitat críptico que sustenta una fauna diversa en un ecosistema en miniatura. Este estudio examina la comunidad de artrópodos de dos tipos de fitotelmata, brácteas y hojas enrolladas presentes en una sola especie, Calathea capitata (Ruiz y Pav.) Lindl. (Zingiberales: Marantaceae), de un sitio de la Amazonia peruana. Se recolectaron artrópodos de ocho brácteas y ocho rollos de hojas. Se encontraron un total de 55 artrópodos (36 adultos, 19 juveniles) en ambos tipos de fitotelmata. En los fitotelmata de brácteas se encontraron: arañas (Araneae: Corinnidae), escarabajos (Coleoptera: Carabidae, Erotylidae, Staphylindae), moscas (Diptera: Limoniidae), una ninfa saltahojas (Hemiptera: Cicadellidae), hormigas (Hymenoptera: Formicidae) y larvas no identificadas se encontraron en muestras de brácteas. En los fitotelmata de hojas enrolladas, se encontraron escarabajos de las hojas (Coleoptera: Chrysomelidae), una tijereta (Dermaptera: Spongiforidae), moscas (Diptera: Drosophilidae), y un saltahojas adulto (Hemiptera: Cicadellidae). Un estudio similar de Calathea lutea Schultes en Perú reveló una comunidad dominada por Coleoptera en fitotelmatas de hojas enrolladas y Diptera en brácteas, con algunos Dermaptera e Hymenoptera, pero sin Araneae o Hemiptera. Este estudio demuestra que los fitotelmata albergan diversos taxones y sirven como vivero para las etapas inmaduras, lo que impacta en los ciclos de vida de la fauna local, lo que a su vez afecta la biodiversidad local.

Livelihood Capitals and Opportunity Cost for Grazing Areas' Restoration: A Sustainable Intensification Strategy in the Ecuadorian Amazon.

Land use change in pastures is considered one of the leading drivers of tropical deforestation in the Ecuadorian Amazon Region (EAR). To halt and reverse this process, it is necessary to understand, among other factors, the local livelihoods, income from grazing area and the appropriate options to foster sustainable production, incorporating the land-sparing and land-sharing approach. This work was conducted using 167 household surveys along an altitudinal gradient within the buffer and transition zone of the Sumaco Biosphere Reserve (SBR) in the EAR. The results of a comparative analysis of the main capital variables (human, social, natural, financial, and physical), and the opportunity cost of grazing area assessment provides the following key findings: (a) the concepts of land sparing and land sharing should be considered as complementary local strategies, including household livelihoods and the opportunity cost of the grazing area; (b) we should encourage markets with differentiated restoration rights, based on households engaged in low grazing areas' opportunity costs, and making less impact on capitals' livelihood a key element of economic and conservation initiatives; and (c) sectoral policy implications, including moderate intensification and technological improvements to strengthen the pastureland-sparing and -sharing approach, are discussed.

Spatial variation of parrotfish assemblages at oceanic islands in the western Caribbean: evidence of indirect effects of fishing?

Fish populations that bear considerable pressure levels tend to show a decline in the average size of individuals, with the small and unexploited species replacing the large and exploited ones. It is important to carry on with their characterization in areas where they are becoming an important source of food for local human populations. An example of such species are parrotfishes, whose responses to external factors such as fishing need to be understood and predicted. In this study, we used a diver-operated stereo-video to examine individual body size, sex ratios and proportion of species of the parrotfish assemblage and analyze them on a qualitative fishing pressure gradient at four oceanic islands in the Colombian Caribbean. We reported over 10,000 occurrences of eleven parrotfish species, of which we estimated the total length of over 90%, grouping them into three size categories (large, medium, and small). Our data showed a spatial variation of parrotfishes' abundances, biomass, and individual body size. Observed differences are size-category-dependent throughout the qualitative fishing pressure. In general, the medium-bodied species had smaller sizes, lower abundances, and thus lower contribution to the total parrotfish biomass at the most heavily fished island. Unexpectedly, we found evidence of possible indirect effects over the small-bodied species Scarus iseri and Scarus taeniopterus with significantly greater abundances, and larger sizes of males of S. iseri, at the higher fishing pressure sites. Overall, our data highlights the extent of the spatial variation in the parrotfish communities at relatively short distances, and present new insights into the responses of parrotfish species on a spectrum of body sizes along a gradient of human pressure.

Does invasion by Pteridium aquilinum (Dennstaedtiaceae) affect the ecological succession in Atlantic Forest areas after a fire?

Pteridium aquilinum (Dennstaedtiaceae) colonization affects ecological and restoration processes. The knowledge of the impacts on the ecological succession by this species allows the use of restoration strategies in invaded environments. This work aimed to evaluate the floristic composition, diversity, structure, density, basal area, height, and diameter of natural regeneration in three areas of the Atlantic Forest in the Serra do Espinhaço Biosphere Reserve in an area invaded by P. aquilinum after a fire. Three environments with different coverage intensities by P. aquilinum were studied, and the plants over 10 cm in height or 5 cm in canopy diameter were measured. The floristic composition and diversity were analyzed using indices presented by Chao, Fisher, Margalef, Pielou, Shannon-Weaver, and Simpson, and similarity was evaluated by the Jaccard index. Species density, basal area, height, and canopy diameter classes were also evaluated. The floristic composition, diversity, structure of natural regeneration, density, and basal area were higher in post-fire areas with a lower coverage by P. aquilinum. The topsoil coverage with plant litter and the possible effect of P. aquilinum allelopathy probably reduced the species richness and diversity. The proportion of plants from the lowest height and canopy diameter classes was higher under moderate coverage by P. aquilinum. The reduction in the floristic composition, diversity, number of species, and basal area in post-fire areas colonized by P. aquilinum is probably due to this species aggressiveness. The population of this plant is high, accumulating large quantities of plant litter as a physical barrier preventing light and propagules from reaching the soil, reducing the germination of the seed bank and, consequently, the natural regeneration. The floristic composition, diversity, structure of natural regeneration, density, and basal area were lower in areas with higher coverage by P. aquilinum. The proportion of plants in the most significant height and canopy diameter classes was higher with reduced coverage by P. aquilinum. The P. aquilinum reduced forest succession in areas after a fire.

Holistic health risk assessment in an artisanal mercury mining region in Mexico.

Mexico is one of the world's leading mercury producers and exporters. However, mercury mining is carried out using artisanal procedures, which highly impact ecosystems. In the municipality of Pinal de Amoles, Queretaro, Mexico, artisanal mercury mining (AMM) is practiced in a region that has been categorized as a Biosphere Reserve. Therefore, a holistic health risk assessment for mercury was performed in the region, including environmental monitoring (air, water, and soil) and mercury exposure in both humans (children, women, and miners) and biota (plants, rodents, and worms). The atmospheric mercury determination was carried out using the JEROME® J405 analyzer, whereas total mercury in environmental and biological samples was determined by atomic absorption spectrophotometry/cold vapor. Results showed that mercury concentrations in the environmental and biological matrices exceeded their respective reference values. These results demonstrate the direct influence of AMM in the increasing levels of mercury in all the components of the studied ecosystem. Therefore, comprehensive intervention strategies must be implemented to reduce and prevent human health and ecological risks due to the presence of mercury. In this regard, the Minamata Convention for mercury control should include biomonitoring programs not only for humans but also for critical ecological receptors in polluted ecosystems.

Multi-matrix approach reveals the distribution of pesticides in a multipurpose protected area from the Atlantic Rainforest: potential risk for aquatic biota and human health?

The Atlantic Rainforest is among the main biodiversity hotspots in the world, the Yabotí Biosphere Reserve (YBR) being one of the most important remaining areas. Agriculture practices could lead to intensive usage of pesticides resulting in a risk to the environment and human health. Water, suspended particulate matter (SPM), sediment, and fish (Andromakhe paris and Andromakhe saguazu) samples were collected from four streams with different degrees of protection of the YBR in two periods in order to assess the distribution of 18 organochlorine pesticides. Legacy and current-use pesticides were found in the different environmental matrices of the stream headwaters in non-anthropized areas within the buffer zone that drains the intangible area. A similar occurrence pattern of pesticides was found in all matrices. Levels of DDTs (<3.63 ng/L) and endosulfans (<21.8 ng/L) in surface water were above international guidelines for the protection of aquatic life in several streams for both sampling periods. HCHs, DDTs, endosulfans, and chlorpyrifos were detected in SPM and sediments from three streams, while γ-HCH (<60.3 ng/g lipid weight), chlorpyrifos (<698 ng/g lw), p,p´-DDD (<367 ng/g lw), and α-endosulfans (<209 ng/g lw) were detected in fish muscle in several streams. Chlorpyrifos and endosulfans were associated with current use, while DDx/DDT ratios suggested an old use. The concentration of pesticides found would not represent a risk to human health; however, it highlights the need to establish better regulation and action guidelines to reduce the anthropogenic effect on natural reserves.

Temporal and spatial segregation of top predators (Felidae) in a Mexican tropical Biosphere Reserve

Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771) are the largest felids in the neotropics. Both can overlap in niche axes (time, space and prey), and are therefore potentially competing species. Segregation mechanisms presented by a low overlap in one of these axes of niche can facilitate the coexistence. Our aim was to analyze jaguar and puma temporal and spatial overlap for understanding their segregation mechanisms. Between 2015 and 2017, twenty-six camera trap stations were located in five habitat types of El Cielo Biosphere Reserve (ECBR) in northeastern Mexico. Temporal activity was analyzed using circular statistics and time overlap analysis. Spatial overlap was calculated with the Pianka index and a selectivity habitat analysis. Our results showed that jaguars and pumas were nocturnal and that the temporal overlap was high (∆4 = 0.77). We found an intermediate spatial overlap (Pianka index = 0.61). Jaguars were more selective and preferred the deciduous forest. In comparison, pumas preferred oak-pine forest, but also used oak and deciduous forest. Our results indicate that spatial segregation best explains the coexistence of jaguars and pumas in our study area, probably due to both habitat diversity in the reserve and the generalist habits of the puma.(AU)

Temporal and spatial segregation of top predators (Felidae) in a Mexican tropical Biosphere Reserve

Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771) are the largest felids in the neotropics. Both can overlap in niche axes (time, space and prey), and are therefore potentially competing species. Segregation mechanisms presented by a low overlap in one of these axes of niche can facilitate the coexistence. Our aim was to analyze jaguar and puma temporal and spatial overlap for understanding their segregation mechanisms. Between 2015 and 2017, twenty-six camera trap stations were located in five habitat types of El Cielo Biosphere Reserve (ECBR) in northeastern Mexico. Temporal activity was analyzed using circular statistics and time overlap analysis. Spatial overlap was calculated with the Pianka index and a selectivity habitat analysis. Our results showed that jaguars and pumas were nocturnal and that the temporal overlap was high (∆4 = 0.77). We found an intermediate spatial overlap (Pianka index = 0.61). Jaguars were more selective and preferred the deciduous forest. In comparison, pumas preferred oak-pine forest, but also used oak and deciduous forest. Our results indicate that spatial segregation best explains the coexistence of jaguars and pumas in our study area, probably due to both habitat diversity in the reserve and the generalist habits of the puma.(AU)

Temporal and spatial segregation of top predators (Felidae) in a Mexican tropical Biosphere Reserve

ABSTRACT Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771) are the largest felids in the neotropics. Both can overlap in niche axes (time, space and prey), and are therefore potentially competing species. Segregation mechanisms presented by a low overlap in one of these axes of niche can facilitate the coexistence. Our aim was to analyze jaguar and puma temporal and spatial overlap for understanding their segregation mechanisms. Between 2015 and 2017, twenty-six camera trap stations were located in five habitat types of El Cielo Biosphere Reserve (ECBR) in northeastern Mexico. Temporal activity was analyzed using circular statistics and time overlap analysis. Spatial overlap was calculated with the Pianka index and a selectivity habitat analysis. Our results showed that jaguars and pumas were nocturnal and that the temporal overlap was high (4 = 0.77). We found an intermediate spatial overlap (Pianka index = 0.61). Jaguars were more selective and preferred the deciduous forest. In comparison, pumas preferred oak-pine forest, but also used oak and deciduous forest. Our results indicate that spatial segregation best explains the coexistence of jaguars and pumas in our study area, probably due to both habitat diversity in the reserve and the generalist habits of the puma.

Organochlorine Pesticides and Potentially Toxic Elements in Groundwater from a Protected Reserve in the Maya Region of Hopelchen, Mexico.

Water quality degradation by organochlorine pesticides and potentially toxic elements is of worldwide concern. This research explores groundwater conditions, regarding organochlorine pesticides and potentially toxic elements, in Hopelchen, Campeche, which is located in the buffer zone of the Calakmul Biosphere Reserve. Unfortunately, agriculture is allowed and agrochemical use is not monitored and sanctioned. Results show that Heptachlor, Endosulfan, and Dieldrin, all recognized carcinogens, had concentrations above the Mexican normative recommended values. Conversely, Cd and Ni concentrations were below recommended values. These results demonstrate that government intervention involving immediate control over agrochemical use is mandatory. Also, the results underscore the contamination of groundwater in several of the Calakmul Biosphere Reserve's buffer zones by organochlorine pesticides concentrations, posing a probable threat for local inhabitants who consume this water and use it for recreation.

Chiggers (Acariformes: Trombiculoidea) do not increase rates of infection by Batrachochytrium dendrobatidis fungus in the endemic Dwarf Mexican Treefrog Tlalocohyla smithii (Anura: Hylidae).

Amphibian populations are globally declining at an alarming rate, and infectious diseases are among the main causes of their decline. Two micro-parasites, the fungus Batrachochytrium dendrobatidis (Bd) and the virus Ranavirus (RV) have caused mass mortality of amphibians and population declines. Other, less understood epizootics are caused by macro-parasites, such as Trombiculoidea chiggers. Infection with chiggers can affect frog behavior and survival. Furthermore, synergistic effects of co-infection with both macro and micro-parasites may lead to higher morbidity. To better understand these potential synergies, we investigated the presence and co-infection by chiggers, Bd and RV in the endemic frog Tlalocohyla smithii (T. smithii). Co-infection of Bd, RV, and/or chiggers is expected in habitats that are suitable for their co-occurrence; and if infection with one parasite facilitates infection with the others. On the other hand, co-infection could decrease if these parasites were to differ in their micro-environmental requirements (i.e. niche apportionment). A total of 116 frogs of T. smithii were studied during 2014 and 2016 in three streams within the Chamela-Cuixmala Biosphere Reserve in Jalisco, Mexico. Our results show that 31% of the frogs were infected with Trombiculoidea chiggers (Hannemania sp. and Eutrombicula alfreddugesi); Hannemania prevalence increased with air temperature and decreased in sites with high canopies and with water pH values above 8.5 and below 6.7. Bd prevalence was 2.6%, RV prevalence was 0%, and none of the frogs infected with chiggers were co-infected with Bd. Together, this study suggests that chiggers do not facilitate infection with Bd, as these are apportioned in different micro-habitats. Nevertheless, the statistical power to assure this is low. We recommend further epidemiological monitoring of multiple parasites in different geographical locations in order to provide insight on the true hazards, risks and conservation options for amphibian populations.

Use and management of wild fauna by people of the Tehuacán-Cuicatlán Valley and surrounding areas, Mexico.

BACKGROUND: Interactions between humans and fauna lay in the heart of the history of human subsistence. In Mesoamerica, the Tehuacán-Cuicatlán Valley (TCV) harbours a high biodiversity with archaeological and ethnoecological evidence of its use by people inhabiting the area since at least 12,000 B.P. It is recognized as one of the most ancient areas of agriculture in the Americas, and a broad spectrum of management practices aimed to ensure the availability of desirable plants has been documented, but it has not been analysed for animals. This study aimed to investigate the use and management practices directed to wild animals along current settlements within the TCV and neighbouring areas. METHODS: We conducted an extensive search, review and analysis of documental sources for the period between 1967 and 2018. We found 38 documents providing information about the presence of animal species and 15 describing their use and/or management. We included our own observations from four case studies among the Ixcatec, Cuicatec, Nahua and Mestizo people, as well as from regional studies of biodiversity. We used unconstrained multivariate data analysis to describe the management typology of the animals in the region. RESULTS: Hitherto, 652 vertebrate species and 765 species of insects have been recorded in this area; and until present, 107 wild animal species have been reported to be used in 11 use-type categories, mostly for food (65.42%), ornamental (27.52%) and medicinal (21.10%) purposes by the Nahua, Cuicatec, Popolocan, Ixcatec, Mazatec and Mestizo people. Their extraction entails manual capture and gathering as well as hunting and trapping strategies, some of them involving planning in time or space and communitarian regulations; in addition, relocation actions and care in captivity were recorded. Nearly 178 of the species distributed in the region with no reports of local use are used in other localities of Mesoamerica. Ethnozoological information is still lacking for the Mixtec, Chinantec and Chocholtec people in the area. CONCLUSIONS: Wild fauna is still a valuable resource for the inhabitants of the TCV. Animals are obtained through extractive practices, which vary from one another in their qualitative attributes. With this work, we provide a context for further research priorities on fauna management in a region of high biocultural significance.

Diversity and seasonal variation of ground and understory spiders from a tropical mountain cloud forest.

We made intensive samplings to study the seasonal response of spiders across different forest strata (ground and understory) in a tropical mountain cloud forest from Mexico. We sampled spiders from ten plots in six sampling events during the dry and rainy season, to analyze their abundance, structure (distribution of abundance among species), diversity and the response of the five dominant species at each stratum. Results demonstrated that seasonal patterns of spider communities differed among strata, revealing a complex spatiotemporal dynamic. Abundance, structure, diversity of ground spiders, as well as the responses of four dominant species at this stratum, showed low seasonal variations. In contrast, a strong seasonal variation was observed for the understory assemblage, with lowest abundance and highest diversity in the rainy season, and different assemblage structures for each season. Seasonal patterns of each assemblage seem linked to the responses of their dominant species. We found high co-occurrence among most of the ground dominant species with similar habitat use and with multivoltine patterns, contrasting with low co-occurrence among most of the understory dominant species with similar habitat use and univoltine patterns. Our results showed that the spiders' assemblages of tropical mountain cloud forest (opposed to what is found in temperate and boreal forests) increase their species richness with the height, and that their responses to seasonal change differ between strata. Management programs of these habitats should consider the spatial and temporal variations found here, as a better understanding of their ecological dynamics is required to support their sustainable management.

A new species of Centruroides (Scorpiones, Buthidae) from Colima, Mexico.

As part of an ongoing survey of scorpion diversity in Colima, Mexico, the isolated mountain Cerro Grande, part of the Biosphere Reserve Sierra de Manantlán, was investigated. Centruroides possanii sp. nov., the fifth species of the genus from the state, was discovered during fieldwork in the massif and is described in the present paper. Physiographical and climatic features of Cerro Grande may restrict the range of this new species; thus, we hypothesized that it may be a microendemic species that requires priority conservation. The new species is not assigned to any Centruroides species group recognized because some of its morphological features do not fit the current diagnosis of any of these groups, and these different groups are non-monophyletic and consequently ill-diagnosed. The new species is profusely illustrated, particularly the hemispermatophore. A distribution map is presented along with the other two more common species distributed in Colima. Because only indirect data on the potency of its venom is available, the medical importance of this new species described here is yet to be known.

Origin and geochemistry of arsenic in surface and groundwaters of Los Pozuelos basin, Puna region, Central Andes, Argentina.

Los Pozuelos is a closed basin in the Puna region of NW Argentina, Central Andes. This is a semi-arid region where closed basins are the most important feature for the hydrologic systems. The center of the basin is occupied by a fluctuating playa lake called Los Pozuelos lagoon, which constitutes a UNESCO Biosphere Reserve. This is one of the most populated closed basins in the Argentinian Puna and residents use groundwater for drinking and cooking. Lowest concentrations of As and dissolved solids are in the headwaters of the rivers (1.46-27 µg/L) and the highest concentrations are in the lagoon (43.7-200.3 µg/L). In groundwater, arsenic concentrations increase from the outer ring aquifer (3.82-29.7 µg/L) composed of alluvial-alluvial fan sediments to the inner lacustrine aquifer (10-113 µg/L) that surround the playa lake. Moreover, high concentrations of As during the dry season (90.2 and 113 µg/L), Na/K mass ratios (0.2 and 0.3), and formation of Na-rich efflorescent salts suggest that high evaporation rates increases As concentration, while rainwater dilutes the concentration during the wet season. As(V) is the dominant species in all the water types, except for the lagoon, where As(III) occasionally dominates because of organic matter buildup. There are at least three potential sources for As in water i) oxidation of As sulfides in Pan de Azúcar mine wastes, and acid mine drainage discharging into the basin; ii) weathering and erosion of mineralized shales; iii) weathering of volcanic eruptive non-mineralized rocks. Because it is a closed basin, the arsenic released from the natural and anthropogenic sources is transported in solution and in fluvial sediments and finally accumulates in the center of the basin where the concentration in water increases by evaporation with occasional enhancement by organic matter interaction in the lagoon.