Herrera Castillo, Lisbeth CarolinaVallejo Palma, GermánSaiz Aparicio, NuriaSánchez Jiménez, AbelIsorna Alonso, EstherRuiz-Jarabo De La Rocha, IgnacioPedro Ormeño, Nuria De2024-10-182024-10-182024-10Herrera-Castillo, L.; Vallejo-Palma, G.; Saiz, N.; Sánchez-Jiménez, A.; Isorna, E.; Ruiz-Jarabo, I.; de Pedro, N. Metabolic Rate of Goldfish (Carassius auratus) in the Face of Common Aquaculture Challenges. Biology 2024, 13, 804. https://doi.org/10.3390/ biology1310080410.3390/ biology13100804https://hdl.handle.net/20.500.14352/109116This study examined the metabolic rate (MO2, oxygen consumption) of goldfish (Carassius auratus) under normal management conditions in aquaculture. Using an intermittent respirometry system, we assessed daily variations and the effects of feeding, handling, temperature increase, and anesthetics. MO2 exhibited a daily rhythm, with higher values during day. Feeding to satiety produced a 35% increase in MO2 compared to fasted animals, with a maximum peak after 3 h and returning to baseline after 7 h. Handling stress (5 min) produced a 140% MO2 peak (from 180 to 252 mg O2 kg−1 h−1), returning to the routine MO2 after 2.5 h. An increase in water temperature (+0.1 °C min−1) up to 30 °C caused MO2 to peak at 200% after 2.5 h from the start of the temperature increase. The use of common anesthetics in aquaculture (MS-222, 2-phenoxyethanol and clove oil in deep anesthesia concentration) affects MO2 during the first few minutes after anesthetic recovery, but also during the following 4 h. It can be concluded that the metabolic rate is a good indicator of the goldfish’s response to aquaculture practices involving energy expenditure and stress. Thus, intermittent respirometry is a valuable non-invasive tool for understanding and improving fish welfare in aquaculture.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article2079-7737https://doi.org/10.3390/biology13100804https://www.mdpi.com/2079-7737/13/10/804open access591.5597.2/.5639.32-PhenoxyethanolClove oilFishMS-222Oxygen consumptionRespirometryStressTemperatureWelfareFisiología animal (Biología)Comportamiento animalPeces2401.13 Fisiología Animal2401.02 Comportamiento Animal2401.14-4 Taxonomía Animal. Peces