Effects of Acute High-Temperature Stress on Physical Responses of Yellowfin Tuna (Thunnus albacares)

Abstract

To understand the physiological reactions of juvenile yellowfin tuna (Thunnus albacares) under acute high-temperature stress, this study measured the changes in biochemical indexes of serum, liver, gill, and muscle of yellowfin tuna under acute high-temperature stress (HT, 34 °C) and a control group (28 °C) for 0 h and 6 h, 24 h and 48 h. The rising speed of water temperature in the HT group was 2 °C/h and the timing started when the temperature reached 34 °C. In the HT group, there was no significant difference between the four adjacent times in cortisol and lactic acid concentration. Serum triglyceride, cholesterol, and alkaline phosphatase concentration were significantly different from the four adjacent times. The superoxide dismutase (SOD) activity in the liver and gills increased at 6 h and 24 h, and the gills and liver had antioxidant reactions in a short time. The malondialdehyde (MDA) concentration in the gills changed significantly at 6 h, while that in the liver did not change significantly. The gills were more sensitive to temperature stress than the liver and muscle. Acute high-temperature stress affected yellowfin tuna’s antioxidant enzymes and metabolic indexes, resulting negative trend in physiological indexes, indicating that yellowfin tuna juveniles are susceptible to elevated temperature.

Experiencing extremes: how Arapaima gigas (Schinz, 1822) deals with increasing water temperatures

“…In this study, plasma triglyceride levels decreased with the increase in temperature, while plasma cholesterol remained unchanged. Studies show that elevated temperatures can reduce plasma concentrations of cholesterol and triglycerides, thus indicating the occurrence of impaired lipid metabolism in acute exposure, or even during heat shock, as a consequence of stress (Li et al 2019;Liu et al 2022). We thought that the increase in temperature would produce an elevation of these metabolites as a result of the mobilization of substrates for energy generation and the maintenance of the homeoviscosity of cell membranes.…”

Exploring the Effects of Acute Stress Exposure on Lumpfish Plasma and Liver Biomarkers

“…Free fatty acids are relevant energy substrates for teleosts and are released due to stress-promoted lipolysis of triglycerides [34,35,69]. However, the relation between triglyceride levels and stress in teleosts is not always straightforward and varies between teleost species and type of stressor, with studies reporting different variations in triglycerides in plasma and liver upon stress challenges [39,[70][71][72][73]. This underscores the importance of understanding the species-specific effects and hypoxia tolerance.…”