Presence of a conspecific causes divergent changes in resting metabolism, depending on its relative size

Millidine, K.J., Metcalfe, N.B. and Armstrong, J.D. (2009) Presence of a conspecific causes divergent changes in resting metabolism, depending on its relative size. Proceedings of the Royal Society of London Series B: Biological Sciences, 276(1675), pp. 3989-3993. (doi: 10.1098/rspb.2009.1219)

Abstract

It is well established that the average metabolism of many species of fish varies with group size. However, it is not clear whether all individuals respond in the same way. Here, we use a newly calibrated method of measuring the metabolic rate of fish from opercular (ventilatory) movements that allows for the first-time estimation of changes in resting metabolic rate (RMR) of each individual within different social groups and when alone. The presence of a conspecific had divergent effects on the RMR of juvenile Atlantic salmon Salmo salar, depending on its relative body size: the presence of a smaller fish caused a 40 per cent reduction, whereas the presence of a slightly larger fish approximately doubled RMR. These effects occurred in the absence of activity and were sustained at lower magnitude in the case of the relatively smaller conspecific even if a transparent barrier prevented any physical interactions between fish. Changes in RMR were mirrored by changes in eye colour that indicate they were linked to stress levels. These contrasting and strong responses show that even the nearby presence of a conspecific can have profound and variable effects on an individual's energy budget; they also highlight the complex trade-offs involved in social interactions

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Millidine, Mrs Karen and Armstrong, Mrs Jennifer and Metcalfe, Professor Neil
• Authors: Millidine, K.J., Metcalfe, N.B., and Armstrong, J.D.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Proceedings of the Royal Society of London Series B: Biological Sciences
• Publisher: The Royal Society
• ISSN: 0962-8452
• ISSN (Online): 1471-2954