The application of X‐radiography in feeding and growth studies with fish: A summary of experiments conducted on arctic charr

The X‐radiographic method first described by Talbot and Higgins (1983) can, with suitable modifications and in combination with other simple techniques, have a wide range of applications in feeding and growth studies with fish. The method can be used for the accurate determination of feed intake, something that is required for the construction of feed tables for farmed fish. The method also may be used in studies designed for the investigation of feeding behavior and modes of feeding. The most useful application may, however, be related to the study of feed‐growth relationships because the method enables the monitoring of feeding and growth performances of individual fish within groups. The application of the method to the study of feed‐growth relationships is described using the effects of different levels of sustained exercise on these relationships as an example. The data show that exposure of fish to moderate water currents for prolonged periods leads to both higher rates of weight gain and improved feed conversion when compared to fish reared in standing water.