Effects of climate scenarios on the growth and physiology of the Amazonian fish tambaqui (Colossoma macropomum) (Characiformes: Serrasalmidae)

Abstract

This study evaluated the effects of three climate scenarios predicted by the Intergovernmental Panel on Climate Change for 2100, on the growth and physiology of the tambaqui (Colossoma macropomum). Juveniles of tambaqui were reared in four rooms (current conditions, and the climate scenarios B1, A1B and A2) for 150 days. Twelve fish were regularly collected for blood analyses and to have their weight and length measured. The amount of food consumed over the experimental period was recorded. Feed intake, weight gain and food conversion showed an increase in all climate scenarios (P < 0.05). Although these results were expected, the increases in weight gain in the more dramatic environmental situations were due to increases in feed intake. Increases in haematocrit, glucose, cortisol and triglycerides within the first 30 days of the experiment were observed. The present results indicate that climate changes can affect not only its feed intake, but also the growth of the tambaqui and that this fish species can recover blood parameters, suggesting an artificial acclimatization to the analysed environmental conditions after 30 days. Taken to nature, these characteristics of the tambaqui could cause ecological imbalances in the food web, in its frequency of occurrence and in its dominance.