Domingos de Jesus Rodrigues

We report the first documented case of albinism in Eira barbara within the Amazon biome. The individual was recorded in Cristalino State Park (Mato Grosso, Brazil) through direct observation and camera traps and showed diagnostic traits of albinism, including yellowish-white fur, reddish eyes, and pinkish skin. This represents the only confirmed Amazonian record and the second known for the species, both in Brazil. Additionally, a leucistic individual was recorded in Tocantins. These records expand knowledge of phenotypic variation in E. barbara and highlight the value of long-term biodiversity monitoring.

Neutrophils play a central role in the innate immune response. However, in inflammatory and autoimmune diseases, the exacerbated activation of these cells can result in excessive release of reactive oxygen species (ROS), proteases, and inflammatory mediators, contributing to tissue damage. In this context, natural compounds derived from amphibian venoms have attracted interest due to their pharmacological and immunomodulatory potential. This study aimed to evaluate in vitro the effects of the crude methanolic extract (CME) of Rhinella marina on the effector functions of human neutrophils. For this purpose, peripheral blood neutrophils from healthy individuals were treated with CME (0.5, 5, and 50 µg/mL) or untreated controls. Cytotoxicity, total ROS production, superoxide anion production, myeloperoxidase (MPO) activity, elastase degranulation, NET (Neutrophil Extracellular Trap) formation, and parameters related to cellular redox status, including antioxidant enzymes and markers of oxidative damage, were evaluated. CME showed concentration-dependent cytotoxicity. There were no changes in ROS production by luminol-dependent chemiluminescence after stimulation with myristoylphorbol acetate (PMA). However, it reduced superoxide anion production in neutrophils in both stimuli in the NBT assay. CME did not significantly modulate MPO activity or NET formation, but it reduced elastase release, suggesting modulation of neutrophil degranulation. Additionally, it increased glutathione-S-transferase (GST) activity and reduced glutathione (GSH) levels. It can be concluded that CME partially modulated neutrophil effector functions, such as superoxide anion production and degranulation, in addition to exhibiting partial protective effects on cellular redox state parameters. These findings suggest the extract’s immunomodulatory potential and reinforce the need for further studies to clarify its mechanisms of action and possible applicability in neutrophil-mediated inflammatory conditions.

Aim: We investigate the distribution of dispersal modes — endozoochory (via animal ingestion), synzoochory (via animal seed accumulation) and anemochory (via wind)—and seed mass of woody plants across Brazilian ecosystems, testing whether their relative abundance in local plant communities could be predicted by climate, edaphic factors and dispersal agents (e.g., the main vectors moving seeds). We expected climate to be the main predictor of dispersal strategy abundance. Location: Brazilian ecosystems (Amazon, Atlantic Forest, Cerrado and Caatinga). Time Period: 2004–2020. Major Taxa Studied: Woody angiosperms, trees and shrubs. Methods: We assigned seed mass to 1984 species and dispersal mode to 2203 species within 300 old‐growth and non‐flooded plots. We employed Random Forest regressions to assess the influence of water availability, temperature seasonality, soil fertility, wind and frugivorous primates on the community‐weighted means of seed mass and dispersal modes. We mapped predictions and estimated the area of applicability to identify regions where predictions were reliable. Results: Climate was the main factor predicting tree dispersal strategies, followed by dispersal agents or soil properties. Endozoochory was prevalent in wetter regions with high water availability and greater diurnal temperature range. Anemochory was more common in drier regions with low water availability, stronger winds and greater diurnal temperature range, whereas synzoochory was more abundant in areas with low temperature seasonality. Heavier seeds were more prevalent in regions with less seasonal temperatures, smaller diurnal temperature ranges and weaker winds. Main Conclusions: Climate is a key predictor of the distribution and prevalence of plants with contrasting dispersal modes and seed masses. We thus expect functional responses to environmental change associated with shifts in the relative abundance of dispersal strategies, with implications for ecosystem services. Our results also highlight the critical role of plot‐based datasets in improving our understanding of how environmental factors influence seed dispersal strategies across tropical ecosystems.

We investigated the effects of environmental temporality (temporary and permanent aquatic systems) and vegetation type on the beta diversity of aquatic macrophytes across major river basins in southern Amazonia. We analyzed aquatic macrophyte diversity across hierarchical basin scales, partitioning beta diversity into turnover and nestedness components, and related community composition to environmental temporality, vegetation type, and spatial structure. A regional checklist was compiled and classified by vegetation type and hydrographic level across the Tapajós, Xingu, Madeira, Araguaia, and Upper Paraguai basins. Floristic similarity was highest between the Tapajós and Xingu basins (48%) and lowest between Araguaia and all other basins (< 10%). Beta diversity increased with spatial scales, mainly driven by species turnover in Tapajós, Xingu, and Madeira basins. Temporary aquatic environments exhibited lower species similarity within and among basins, reflecting their dynamic and heterogeneous nature. These patterns were consistent across different vegetation types, indicating that hydroperiod has a stronger influence on species composition than surrounding terrestrial vegetation. Overall, aquatic macrophyte assemblages in southern Amazonian basins are compositionally distinct and strongly structured by the permanence of aquatic environments. Temporary systems emerge as key determinants of regional beta diversity of macrophytes, underscoring their ecological importance and vulnerability to hydrological changes.

Indigenous peoples play a central role in biodiversity knowledge and conservation, yet their participation in scientific research remains underrepresented. Understanding how Indigenous peoples, traditional knowledge, and Indigenous territories are portrayed in the scientific literature is essential for developing more equitable and culturally grounded conservation strategies. We conducted a bibliometric analysis of 94 articles on biodiversity conservation in the Amazon, published between 1997 and 2025, indexed in Scopus and Web of Science. We examined temporal trends, geographic distribution, institutional leadership, Indigenous co-authorship, focal ecosystems and taxa, and the main contributions attributed to Indigenous peoples. Indigenous perspectives were integrated into this analysis through a participatory approach. Scientific production increased after 2010. Research leadership remains concentrated in institutions from the Global North, even though Brazil, Ecuador, and Peru were the most frequently studied countries. Indigenous co-authorship was identified in only 6.4 % of the studies. Most studies focused on plants, mammals, and birds, whereas aquatic environments and groups such as insects, amphibians, and reptiles received comparatively less attention. The main contributions attributed to Indigenous peoples were related to community-based monitoring and management (41.48%) and cultural practices and traditional ecological knowledge (38.19%). These findings show that Indigenous peoples are widely recognized as knowledge holders and conservation actors, but are still rarely included as authors or research partners. Our study highlights persistent geographic, epistemic, and collaborative asymmetries in Amazonian biodiversity research. Conservation science and policy will be stronger, fairer, and more effective when they move beyond documenting Indigenous knowledge towards supporting Indigenous leadership, equitable partnerships, and inclusive co-production of knowledge.

Skin secretions from toads of the Bufonidae family contain immunomodulatory and antioxidant substances and have pharmaceutical potential for treating cancer, degenerative diseases, and cardiovascular conditions. Previous studies have demonstrated that the methanolic extracts of Rhinella marina and Rhaebo guttatus have an immunomodulatory effect on murine macrophages, stimulating the production of pro-inflammatory cytokines and hydrogen peroxide. However, little is known about its effect on human monocytes. Therefore, the aim of this study was to evaluate the in vitro effect of these extracts on the function of human peripheral blood monocytes by assessing cytotoxicity and the production of nitric oxide and hydrogen peroxide. The amphibians were collected in Mato Grosso, Brazil. In the laboratory, their paratoid glands were compressed to extract the venom. Voucher specimens were deposited in the Biological Collection of the Southern Amazon (Sinop/MT). To obtain monocytes, peripheral blood samples were collected from 16 healthy individuals (aged 30 – 45 years) who had not used any class of medication for the previous 15 days. The monocytes were cultured (5% CO2 at 37°C) with different extract concentrations for 18 h (for cytotoxicity assessment) or 24 h (for activity assessment). For R. marina venom, the most toxic concentration was 1000 µL mL-1, whereas non-toxic concentrations were 62.5 µL mL-1, 15.63 µL mL-1, and 7.8 µL mL-1. For R. guttatus, concentrations ranging from 1000 µL mL-1 to 31.25 µL mL-1 were the most toxic, and the non-toxic concentrations were 15.63 µL mL-1 and 7.8 µL mL-1. The cells did not produce nitric oxide or hydrogen peroxide in response to stimulation with the extracts. We conclude that extracts from the skin secretions of R. marina and R. guttatus exhibit a concentration-dependent cytotoxic effect on human monocytes but do not modulate the cells’ in vitro ability to produce nitric oxide and hydrogen peroxide.

This review raises awareness of the Cerrado’s value to society and serves as an informative guide for ecology professionals, policymakers, and anyone interested in biodiversity conservation. Herein, we comprehensively and critically address the ongoing degradation process of the Cerrado, highlighting its ecological complexity, biological diversity, and strategic importance for environmental sustainability and climate change mitigation in Brazil. We examine the diversity of ecosystems in the Cerrado, highlighting their specific vulnerabilities and the inadequacy of current legal instruments to guarantee their protection. Our analysis covers the main vectors of pressure on the territory, such as the advance of the agricultural frontier, the predatory use of fire, the silent water crisis, and threats to Indigenous peoples, highlighting how these factors operate in an interconnected manner to disrupt the region’s ecosystem services. The limitations of current conservation policies and the invisibility of species and ecosystems in the face of the dominant legal and economic systems are also discussed. Our review proposes ways to mitigate or even reverse this scenario, including increasing the number of Conservation Units and Indigenous lands, valuing regenerative economies, expanding protected areas, and strengthening territorial and climate governance. The defense of the Cerrado is presented here not only as an ecological imperative but as an agenda for environmental justice, water security, and intergenerational responsibility. By integrating data, references, conceptual reflections, and action strategies, we hope to contribute to repositioning the Cerrado at the center of discussions on conservation, climate, and sustainable development.