Integrated Oxygen Consumption Rate, Energy Metabolism, and Transcriptome Analysis Reveal the Heat Sensitivity of Wild Amur Grayling (Thymallus grubii) Under Acute Warming
Year: 2025
Type: article
Abstract: Cold-water fish, particularly stenothermal species, are increasingly affected by rising temperatures driven by global warming. To explore the hepatic metabolism mode of Amur grayling under warming, Thymallus grubii was selected as the experimental model. Here, we measured the oxygen consumption rate (MO2), energy metabolism enzymes, and transcription profiling in Thymallus grubii that was exposed to increased temperatures (9, 12, 15, 18, 21, and 24 °C) with the same flow velocity (34 cm/s). In this study, MO2 initially increased and then decreased with rising temperature, with peak sensitivity between 12 and 15 °C (Q10 = 5.30). Hemoglobin increased significantly at 12–18 °C but decreased in the 18–24 °C group (p < 0.05). Additionally, hepatic glycogen content (the amount of stored sugar in the liver, which serves as an energy reserve) also first increased and then decreased markedly (p < 0.05). Lactic acid in plasma and muscle contents increased, but creatine phosphate and glucose levels significantly decreased (p < 0.05). The result of transcriptome analysis showed that individuals in the 15 °C group could supply energy through glucose and amino acid metabolism. In contrast, individuals under 21 °C exposure could mainly supply energy through the lipid metabolism pathway. Our study underscores the vulnerability of Amur grayling to environmental temperature and identifies the instantaneous metabolic limit range, providing numerical limits (e.g., maximum river temperature) that managers can use to protect wild populations.
Source: Biology
Authors: Cunhua Zhai, Ziyang Wang, Luye Bai, Bo Ma
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,258
OpenAlex ID: W4416858634