Fish mortality in the Amazonian drought of 2023: the role of experimental biology in our response to climate change.

Higher temperatures exacerbate drought conditions by increasing evaporation rates, reducing soil moisture and altering precipitation patterns. As global temperatures rise as a result of climate change, these effects intensify, leading to more frequent and severe droughts. This link between higher temperatures and drought is particularly evident in sensitive ecosystems like the Amazon rainforest, where reduced rainfall and higher evaporation rates result in significantly lower water levels, threatening biodiversity and human livelihoods.

Oil spill in an amazon blackwater environment: Biochemical and physiological responses of local fish species.

The accidental spill of petroleum asphalt cement (PAC) in São Raimundo (SR Harbor, located on the Rio Negro (Manaus, Amazonas, Brazil) was monitored through the analysis of polyciclic aromatic hydrocarbons (PAHs) in water and a set of biomarkers in fishes (exposure biomarkes: PAHs-type metabolites concentrations in bile; the activities of ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in liver. Effect biomarkers: lipid peroxidation concentration (LPO) in liver, acetylcholinesterase activity in brain, and genotoxic DNA damage in erythrocytes). Two fish species, Acarichthys heckelii and Satanoperca jurupari, were collected 10, 45, and 90 days after the PAC spill in São Raimundo.

Gut microbiota of an Amazonian fish in a heterogeneous riverscape: integrating genotype, environment, and parasitic infections.

A number of key factors can structure the gut microbiota of fish such as environment, diet, health state, and genotype. , an Amazonian cichlid, is a relevant model organism to study the relative contribution of these factors on the community structure of fish gut microbiota. has well-studied genetic populations and thrives in rivers with drastically divergent physicochemical characteristics.

Important role of endogenous microbial symbionts of fish gills in the challenging but highly biodiverse Amazonian blackwaters.

Amazonian blackwaters are extremely biodiverse systems containing some of Earth's most naturally acidic, dissolved organic carbon -rich and ion-poor waters. Physiological adaptations of fish facing these ionoregulatory challenges are unresolved but could involve microbially-mediated processes. Here, we characterize the physiological response of 964 fish-microbe systems from four blackwater Teleost species along a natural hydrochemical gradient, using dual RNA-Seq and 16 S rRNA of gill samples.

Genomic and Environmental Factors Shape the Active Gill Bacterial Community of an Amazonian Teleost Holobiont.

Fish bacterial communities provide functions critical for their host's survival in contrasting environments. These communities are sensitive to environmental-specific factors (i.e.

Genomics of Serrasalmidae teleosts through the lens of microbiome fingerprinting.

Associations between host genotype and host-associated microbiomes have been shown in a variety of animal clades, but studies on teleosts mostly show weak associations. Our study aimed to explore these relationships in four sympatric Serrasalmidae (i.e.

Global change and physiological challenges for fish of the Amazon today and in the near future.

Amazonia is home to 15% (>2700, in 18 orders) of all the freshwater fish species of the world, many endemic to the region, has 65 million years of evolutionary history and accounts for 20% of all freshwater discharge to the oceans. These characteristics make Amazonia a unique region in the world. We review the geological history of the environment, its current biogeochemistry and the evolutionary forces that led to the present endemic fish species that are distributed amongst three very different water types: black waters [acidic, ion-poor, rich in dissolved organic carbon (DOC)], white waters (circumneutral, particle-rich) and clear waters (circumneutral, ion-poor, DOC-poor).

Amazon fish bacterial communities show structural convergence along widespread hydrochemical gradients.

The world's richest freshwater fish community thrives in gradients of contrasting environments in Amazonia, ranging from ion-poor acidic black waters, to ion-rich circumneutral white waters. These hydrochemical gradients structure Amazonian fish assemblages via ecological speciation events. Fish bacterial communities contain an important genetic heritage essential for their hosts' survival and are also involved in adaptive divergence via niche adaptation processes, but the extent to which they evolve in response to hydrochemical gradients in Amazonia is unknown.

pH drop impacts differentially skin and gut microbiota of the Amazonian fish tambaqui (Colossoma macropomum).

Aquatic organisms are increasingly exposed to lowering of environmental pH due to anthropogenic pressure (e.g. acid rain, acid mine drainages).

Effects of Combined Resistance and Endurance Training Versus Resistance Training Alone on Strength, Exercise Capacity, and Quality of Life in Patients With COPD.

Purpose: To compare the effects of 12-week training periods (2 d·wk) involving resistance training only with the effects of 12-week training periods involving combined resistance (once weekly) and endurance (once weekly) training on strength, endurance performance, and quality of life.

Methods: Thirty-six patients with moderate-to-severe chronic obstructive pulmonary disease were randomized to combined training (REG), resistance training alone (RG), or control (CG) groups. Patients were tested for maximal strength of the upper and lower extremities, power output of the lower extremities, maximal (Wmax) and submaximal exercise capacity, performance on a 6-minute walk test (6MWT), and quality of life.

Health-related quality of life in patients with osteoarthritis after total knee replacement: factors influencing outcomes at 36 months of follow-up.

Objectives: (1) To evaluate health-related quality of life (HRQL) in patients with severe osteoarthritis (OA) undergoing total knee replacement (TKR) and (2) to identify the influence of sociodemographic, clinical, intra-operative and postoperative variables on HRQL at 36 months after TKR.

Design: Prospective study with a 36-month follow-up. Preoperative interviews were carried out with 90 in-patients.

Protection by natural blackwater against disturbances in ion fluxes caused by low pH exposure in freshwater stingrays endemic to the Rio Negro.

Stenohaline freshwater stingrays (Potamotrygon spp.) are endemic to the very dilute (Na(+), Cl(-), Ca2(+) View Article and Find Full Text PDF