Tissue distribution of appetite regulation genes and their expression in the Amazon fish Colossoma macropomum exposed to climate change scenario.

Climate change leads to an increase in water acidification and temperature, two environmental factors that can change fish appetite and metabolism, affecting fish population in both wild and aquaculture facilities. Therefore, our study tested if climate change affects gene expression levels of two appetite-regulating peptides - Neuropeptide Y (NPY) and Cholecystokinin (CCK) - in the brain of tambaqui, Colossoma macropomum. Additionally, we show the distribution of these genes throughout the body.

Reactive oxygen species and other biochemical and morphological biomarkers in the gills and kidneys of the Neotropical freshwater fish, Prochilodus lineatus, exposed to titanium dioxide (TiO) nanoparticles.

This study investigated the action of titanium dioxide nanoparticles (TiO-NPs), on the gills and kidneys of Neotropical freshwater fish, Prochilodus lineatus, with emphasis on reactive oxygen species (ROS) production, antioxidant responses, and morphological changes. Fish were exposed to 1, 5, 10, and 50 mg L nominal TiO-NPs suspended into water for 2 or 14 days. In gills, ROS decreased and glutathione (GSH) increased after 2 days, while ROS and GSH increased and superoxide dismutase activity decreased after 14 days.