Major shifts in biogeographic regions of freshwater fishes as evidence of the Anthropocene epoch.

Animals and plants worldwide are structured in global biogeographic regions, which were shaped by major geologic forces during Earth history. Recently, humans have changed the course of events by multiplying global pathways of introduction for nonindigenous species and propagating local species extirpations. Here, we report on how introductions and extirpations have changed the distributions of freshwater fishes worldwide and how it affected their natural biogeographic regions.

Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna.

Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes-the most species-rich continental vertebrate fauna on Earth-to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades.

NEOTROPICAL FRESHWATER FISHES: A dataset of occurrence and abundance of freshwater fishes in the Neotropics.

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.

Large-scale Degradation of the Tocantins-Araguaia River Basin.

The Tocantins-Araguaia Basin is one of the largest river systems in South America, located entirely within Brazilian territory. In the last decades, capital-concentrating activities such as agribusiness, mining, and hydropower promoted extensive changes in land cover, hydrology, and environmental conditions. These changes are jeopardizing the basin's biodiversity and ecosystem services.

Trade-off between number and length of remote videos for rapid assessments of reef fish assemblages.

Remote underwater videos are widely employed to assess the structure and composition of reef fish assemblages but the sampling effort employed on each survey differs considerably, indicating that both the number of assessments and video length could be optimized. We searched for this optimal sampling effort in remote video samples to conduct rapid assessments of community composition and discussed the relation between number of replicates and video length, and how it impacts the method's efficiency to characterize species assemblages. Remote video recordings from tropical reefs in northeastern Brazil were used to investigate how fish species richness and composition builds across time and number of assays.

Historical distribution and current drivers of guppy occurrence in Brazil.

Humans introduce non-native species by means such as the deliberate release of fish into fresh waters and through commercial trade. The guppy Poecilia reticulata Peters, 1859, is commonly kept in aquaria and controls disease vectors, and now it occurs in many areas outside its natural distribution. Its initial habitat in Brazil was identified, and a study was performed to determine whether the density of guppies can be explained by the density of human population, per-capita gross domestic product, level of human impact on the areas where guppies have been found and fish-sampling effort.

Freshwater fish diversity hotspots for conservation priorities in the Amazon Basin.

Conserving freshwater habitats and their biodiversity in the Amazon Basin is a growing challenge in the face of rapid anthropogenic changes. We used the most comprehensive fish-occurrence database available (2355 valid species; 21,248 sampling points) and 3 ecological criteria (irreplaceability, representativeness, and vulnerability) to identify biodiversity hotspots based on 6 conservation templates (3 proactive, 1 reactive, 1 representative, and 1 balanced) to provide a set of alternative planning solutions for freshwater fish protection in the Amazon Basin. We identified empirically for each template the 17% of sub-basins that should be conserved and performed a prioritization analysis by identifying current and future (2050) threats (i.

Unexpected fish diversity gradients in the Amazon basin.

Using the most comprehensive fish occurrence database, we evaluated the importance of ecological and historical drivers in diversity patterns of subdrainage basins across the Amazon system. Linear models reveal the influence of climatic conditions, habitat size and sub-basin isolation on species diversity. Unexpectedly, the species richness model also highlighted a negative upriver-downriver gradient, contrary to predictions of increasing richness at more downriver locations along fluvial gradients.

Interleukin-17/interleukin-17 receptor axis elicits intestinal neutrophil migration, restrains gut dysbiosis and lipopolysaccharide translocation in high-fat diet-induced metabolic syndrome model.

Sound evidence supports a role for interleukin-17 (IL-17) -producing γδ T cells and IL-17-producing helper T (Th17) cells in intestinal homeostasis, especially in intestinal barrier integrity. In the present study, we aimed to evaluate the role of IL-17 cytokine in the regulation of intestinal immunity and obesity-induced metabolic syndrome (MetS) in an experimental murine model. C57BL/6 wild-type (WT) mice and mice lacking the IL-17 cytokine receptor (IL-17RA ) were fed either a control diet (CD) or a high-fat diet (HFD) for 9 weeks.

Interleukin-23 promotes intestinal T helper type17 immunity and ameliorates obesity-associated metabolic syndrome in a murine high-fat diet model.

We addressed the role of interleukin-23 (IL-23) in driving the intestinal T helper type 17 (Th17) response during obesity and metabolic syndrome progression induced by a high-fat diet (HFD). Diet-induced obese and lean mice received HFD or control diet (CTD), respectively, for 20 weeks. The nutritional, metabolic and immune parameters were examined at weeks 9 and 20.

A global database on freshwater fish species occurrence in drainage basins.

A growing interest is devoted to global-scale approaches in ecology and evolution that examine patterns and determinants of species diversity and the threats resulting from global change. These analyses obviously require global datasets of species distribution. Freshwater systems house a disproportionately high fraction of the global fish diversity considering the small proportion of the earth's surface that they occupy, and are one of the most threatened habitats on Earth.

Chronic Infection Exacerbates Secondary Polymicrobial Sepsis.

Sepsis is a severe syndrome that arises when the host response to an insult is exacerbated, leading to organ failure and frequently to death. How a chronic infection that causes a prolonged Th1 expansion affects the course of sepsis is unknown. In this study, we showed that mice chronically infected with were more susceptible to sepsis induced by cecal ligation and puncture (CLP).

Nucleotide-binding oligomerization domain-containing protein 2 prompts potent inflammatory stimuli during Neospora caninum infection.

Neospora caninum is an apicomplexan parasite responsible for major economic losses due to abortions in cattle. Innate immune responses are crucial for host resistance against the infection, however the molecules involved in parasite recognition are still poorly understood. Nod2 is a cytosolic receptor that recognizes several pathogens and its role during N.

Global imprint of historical connectivity on freshwater fish biodiversity.

The relative importance of contemporary and historical processes is central for understanding biodiversity patterns. While several studies show that past conditions can partly explain the current biodiversity patterns, the role of history remains elusive. We reconstructed palaeo-drainage basins under lower sea level conditions (Last Glacial Maximum) to test whether the historical connectivity between basins left an imprint on the global patterns of freshwater fish biodiversity.

Effects of reduced-impact logging on fish assemblages in central Amazonia.

In Amazonia reduced-impact logging, which is meant to reduce environmental disturbance by controlling stem-fall directions and minimizing construction of access roads, has been applied to large areas containing thousands of streams. We investigated the effects of reduced-impact logging on environmental variables and the composition of fish in forest streams in a commercial logging concession in central Amazonia, Amazonas State, Brazil. To evaluate short-term effects, we sampled 11 streams before and after logging in one harvest area.