Rates of oxygen consumption at rest (MO2) were measured in intermittent flow Perspex respirometric chambers (customized by JEMITEC Technische Komponenten, Garlstor, Germany; 500-ml volume) keeping 24 animals at normoxia and 24 at hyperoxia. MO2 was measured using an oxygen sensor spot (Sensor Type PSt3 PreSens, Regensburg, Germany), glued to the inside wall of the chamber and connected to a single-channel oxygen transmitter Fibox (Microx) 4 (PreSens, Regensburg, Germany) through an optical fiber. No spontaneous activity was noticed during the measurements. For each oxygen treatment, we increased temperature at 1°C steps (obtained with the control of the water bath; GP 200, Grant Instruments, Cambridge, UK) every 30 min and measured MO2 at seawater temperatures of 20°, 30°, 38°, 40°, 42°C. Each measurement was carried out during the final 5 min of the 30-min step by closing the respiratory chambers, and the oxygen saturation never decreased by more than 5% of the value of the corresponding treatment.

Following the procedure used by Fusi et al. (32), for each measurement, we kept two chambers empty as controls to assess the microbial oxygen consumption at the temperatures tested. Prior to and after the measurements, all the hoses and tubes, as well as the connectors, were cleaned in alcohol 70% and in bleach 10% and carefully rinsed with sterile Milli-Q water. This treatment ensured the removal of microorganisms. In addition, prior to placing animals in the chambers, we gently cleaned the carapace with sterile seawater to minimize contamination of microbes carried by the animals. At lower temperatures (20° to 30°C), the microbial oxygen consumption was negligible, and at higher temperatures, it was less than 1% of crab consumption. The water used in the experiment was prefiltered seawater to minimize the contamination of microbes.

Note: The content above has been extracted from a research article, so it may not display correctly.

Please log in to submit your questions online.
Your question will be posted on the Bio-101 website. We will send your questions to the authors of this protocol and Bio-protocol community members who are experienced with this method. you will be informed using the email address associated with your Bio-protocol account.

We use cookies on this site to enhance your user experience. By using our website, you are agreeing to allow the storage of cookies on your computer.