A novel 1 liter flow-through calorimeter for heat production measurements on aquatic animals without stress

Abstract

A special custom-made 1 liter differential flow-through calorimeter (Sétaram GF108) has been adapted for flow-through heat flux measurements of aquatic animals. The lower limit of detection in a 1 liter vessel is 0.1 mW, whereas the sensitivity shows a linear correlation with the flow velocity up to at least 60 ml min −1. By carefully choosing the conditions and allowing enough time for adaptation, it appears to be possible to obtain data from stress-free animals. In this way the heat production of aquatic animals as a measure of total metabolic activity can be determined under aerobic or anaerobic conditions. During anoxia the heat production in goldfish falls to 30% of the nonnoxic level. This apparatus is a major breakthrough in direct calorimetry of animals, owing to the constant conditions and to its advanced electronics.