Acclimation to constant and fluctuating temperatures promotes distinct metabolic responses in Arctic char (Salvelinus alpinus).

The Arctic is warming three times faster than the global average, imposing challenges to cold-adapted fish, such as Arctic char (Salvelinus alpinus). We evaluated stress and metabolic responses of Arctic char to different thermal acclimation scenarios to determine whether responses to thermal variation differed from those to stable exposures. Fish were exposed for 7 days to one of four treatments: (1) control (12°C); (2) mean (16°C), corresponding to the mean temperature of the diel thermal cycle; (3) constant high temperature (20°C); and (4) diel thermal cycling (12 to 20°C every 24 h).

The biotic ligand model as a promising tool to predict Cu toxicity in amazon blackwaters.

The Rio Negro basin of Amazonia (Brazil) is a hotspot of fish biodiversity that is under threat from copper (Cu) pollution. The very ion-poor blackwaters have a high dissolved organic carbon (DOC) concentration. We investigated the Cu sensitivity of nine Amazonian fish species in their natural blackwaters (Rio Negro).

Malathion alters the transcription of target genes of the tumour suppressor tp53 and cancerous processes in Colossoma macropomum: Mechanisms of DNA damage response, oxidative stress and apoptosis.

Different classes of pesticides such as fungicides, herbicides, and insecticides, can induce differential expression of genes that are involved in tumorigenesis events in fish, including the expression of tumor suppressor tp53. The degree and duration of the stressful condition is decisive in defining which tp53-dependent pathway will be activated. Herein we evaluate the target genes expression that participates in the regulation pathway of the tumor suppressor tp53 and in the cancerous processes in tambaqui after exposure to malathion.

Vitellogenin Ab structure of the amazonian Arapaima gigas.

The vitellogenin is composed by polypeptides that are precursors of egg yolk proteins that provides embryo and larvae nutrition. The mRNA encoding for vitellogenin Ab (Vtg-Ab; 4,536 bp long and 1,512 amino acids) were obtained by RNA-Seq library sequencing of pirarucu gonads. The Vtg-Ab sequences had high homology with Vtgs of other three teleosts species of the order Osteoglossiformes.