Endocrine disruption caused by the aquatic exposure to aluminum and manganese in Astyanax altiparanae (Teleostei: Characidae) females during the final ovarian maturation.

Aluminum (Al) and manganese (Mn) can be toxic to aquatic biota and cause endocrine disruption in fish, affecting reproduction. This study evaluates the physiological responses of the ray-finned teleost fish Astyanax altiparanae vitellogenic females after acute exposure (96 h) to Al and Mn (alone and combined) in acid pH followed by the same period of exposure to metal-free water in neutral pH. The aim of this second period of exposure was to assess the recovery capacity from the toxic effects these metals.

Aluminum bioconcentration in female Nile tilapia Oreochromis niloticus (Perciformes: Cichlidae) and the effects on pituitary gonadotropins.

In this study, we measured aluminum (Al) bioconcentration in the brain, ovaries, and liver of Oreochromis niloticus females, and analyzed the effects of exposure to Al and acidic pH on the gene expression of follicle-stimulating hormone (βfsh) and luteinizing hormone (βlh) in these animals. Mature females were divided into 4 groups, thus being maintained for 96 h in one of the following conditions: control at neutral pH (Ctr); Al at neutral pH (Al); acidic pH (Ac), and Al at acidic pH (Al-Ac). pH alone did not influence Al bioconcentration in the brain.

Water temperature and acid pH influence the cytotoxic and genotoxic effects of aluminum in the freshwater teleost Astyanax altiparanae (Teleostei: Characidae).

The toxicity of metals, including aluminum (Al), can be potentiated by temperature and acid pH, a concern in view of the current global warming scenario. The aim of this study was to evaluate the bioconcentration of Al in the testes and semen of Astyanax altiparanae and the potential of this metal, at different environmental temperatures and acid pH, to cause cytotoxicity and genotocixity in erythrocytes and spermatozoa. A.

Nickel toxicity to cardinal tetra (Paracheirodon axelrodi) differs seasonally and among the black, white and clear river waters of the Amazon basin.

This study investigated the acute toxicity of nickel (Ni) to cardinal tetra (Paracheirodon axelrodi), within the three main water types of the Amazon basin: black (Rio Negro), white (Rio Solimões) and clear (Rio Tapajós) during the wet and dry season at pH 7 (representative of white and clear rivers) and pH 4 (representative of black waters). The influence of dissolved organic carbon (DOC) quality on Ni toxicity within the three waters was also explored via the use of DOC isolates. Differences in water chemistry, DOC quality and ion concentrations were shown between waters and between seasons.

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).