Open-top static respirometry is a reliable method to determine the routine metabolic rate of barramundi, Lates calcarifer

• Published in: Marine and freshwater behaviour and physiology Vol. 47; no. 1; pp. 19 - 28
• Main Authors: Gamble, S, Carton, A.G, Pirozzi, I
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 02-01-2014
• Subjects: aerobiosis; barramundi, Lates calcarifer; closed-top respirometry; fish; Freshwater; gas exchange; Lates calcarifer; Marine; metabolism; open-top respirometry; oxygen consumption; temperature
• ISSN: 1029-0362; 1023-6244; 1029-0362
• DOI: 10.1080/10236244.2013.874119

Closed-system respirometry is a standard technique used to determine aerobic metabolism of aquatic organisms. Open-top systems are rarely used due to concerns of gas exchange across the air–water interface. Here, we evaluated an open-top respirometry system by comparing the mass-specific routine metabolic rate (RMR) of the tropical diadromous finfish barramundi, Lates calcarifer , in both closed-top and open-top respirometers. The RMR of 190 g barramundi was determined across broad temperatures ranging from 18 to 38 °C. There was no significant difference in RMR between barramundi in either closed- or open-top respirometers at any temperature (p > 0.05). To ensure RMR measurements were not an artifact of the respirometry system, barramundi were reciprocally transplanted into either respective closed-top or open-top respirometer and oxygen consumption re-measured at each temperature treatment. The RMR of transplanted barramundi was found to be virtually identical in either respirometer. RMR increased linearly with increasing temperature; the relationship between RMR and temperature (T ; 18–38 °C) can be described as 3.658 T −36.294 mg O ₂ kg ⁻⁰.⁸ h ⁻¹. The daily energetic cost of RMR was 1.193 T −11.838 kJ kg ⁻⁰.⁸ day ⁻¹. Q ₁₀ for barramundi increased significantly with increasing temperature (p < 0.0001). Q ₁₀₍₁₈–₂₈₎ was the lowest at 1.7 and Q ₁₀₍₂₈–₃₈₎ the highest at 1.9, over the whole experiment temp range Q ₁₀₍₁₈–₂₈₎ was 1.8. The current study demonstrates that open-top respirometry is a reliable and practical alternative to closed-top respirometry for accurate determination of the aerobic metabolism of barramundi and has potential application for a number of different aquatic organisms.