Colossoma macropomum (Characiformes: Serrasalmidae) adapted to new climate regime: Differential gene expression from farmed tambaqui juveniles raised in subtropical and tropical regions

Abstract

The Brazilian native fish species with the highest potential in fish farm is Colossoma macropomum. This work investigated whether two populations of farmed C. macropomum respond equally to their captive habitats. 20 tambaqui juveniles from the Brazilian fish farms Balbina and Brumado were selected. We examined genes of specific metabolic pathways: hsp70, hif-1α, per-1, cry-1, acly, mstn, ube3a, ras and ogt. Expression of ras (p = 0.041), cry-1 (p = 0.001), per-1 (p = 0.001), ogt (p = 0.001) and acly (p = 0.025) were significantly lower in Brumado fish. Heatmaps showed extreme relative expression differences for some genes. Integrated biomarker response values for Balbina and Brumado populations were 42.7 and 6.79, respectively. In general, the Brumado population presented lower gene expression than Balbina fish. The differential genetic structure of the populations is likely the most impacting factor, suggesting local adaptation.