Salin 2016 J Exp Biol
|Salin K, Auer SK, Anderson GJ, Selman C, Metcalfe NB (2016) Inadequate food intake at high temperatures is related to depressed mitochondrial respiratory capacity. J Exp Biol 219:1356-62.|
Abstract: Animals, especially ectotherms, are highly sensitive to the temperature of their surrounding environment. Extremely high temperature, for example, induces a decline of average performance of conspecifics within a population, but individual heterogeneity in the ability to cope with elevating temperatures has rarely been studied. In this study, we examined inter-individual variation in feeding ability and consequent growth rate of juvenile brown trout Salmo trutta acclimated to a high temperature (19°C), and investigated the relationship between these metrics of whole-animal performances and among-individual variation in mitochondrial respiration capacity. Food was provided ad libitum yet intake varied ten-fold amongst individuals, resulting in some fish losing weight whilst others continued to grow. Almost half of the variation in food intake was related to variability in mitochondrial capacity: low intake (and hence growth failure) was associated with high LEAK respiration rates within liver and muscle mitochondria, and a lower coupling of muscle mitochondria. These observations, combined with the inability of fish with low food consumption to increase their intake despite ad libitum food levels, suggest a possible insufficient capacity of the mitochondria for maintaining ATP homeostasis. Individual variation in thermal performance is likely to confer variation in the upper limit of an organism's thermal niche and in turn affect the structure of wild populations in warming environments.
© 2016. Published by The Company of Biologists Ltd. • Keywords: Ecophysiology, Food intake, Global warming, Proton leak, Respiratory control ratio, Respiration rate
Labels: MiParea: Respiration, Comparative MiP;environmental MiP, Exercise physiology;nutrition;life style
Stress:Temperature Organism: Fishes Tissue;cell: Skeletal muscle, Liver Preparation: Permeabilized tissue
Coupling state: LEAK, OXPHOS Pathway: N, S, CIV, NS, Other combinations, ROX HRR: Oxygraph-2k