title: Balancing of lipid, protein, and carbohydrate intake in a predatory beetle following hibernation, and consequences for lipid restoration.
abstract: Carnivorous animals are known to balance their consumption of lipid and protein, and recent studies indicate that some mammalian carnivores also regulate their intake of carbohydrate. We investigated macronutrient balancing and lipid restoration following hibernation in the ground beetle Anchomenus dorsalis, hypothesizing that carbohydrates might be important energy sources upon hibernation when predator lipid stores are exhausted and prey are equally lean. We recorded the consumption of lipid, protein, and carbohydrate over nine days following hibernation, as the beetles foraged to refill their lipid stores. Each beetle was given the opportunity to regulate consumption from two semi-artificial foods differing in the proportion of two of the three macronutrients, while the third macronutrient was kept constant. When analyzing consumption of the three macronutrients on an energetic basis, it became apparent that the beetles regulated lipid and carbohydrate energy interchangeably and balanced the combined energy intake from the two macronutrients against protein intake. Restoration of lipid stores was independent of the availability of any specific macronutrient. However, the energetic consumption required to refill lipid stores was higher when a low proportion of lipids was ingested, suggesting that lipids were readily converted into lipid stores while there were energetic costs associated with converting carbohydrate and protein into stored lipids. Our experiment demonstrates that carbohydrates are consumed and regulated as a non-protein energy source by A. dorsalis despite an expectedly low occurrence of carbohydrates in their natural diet. Perhaps carbohydrates are in fact an overlooked supplementary energy source in the diet of carnivorous arthropods.
authors: Department of Bioscience, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark; Department of Biosciences, University of Helsinki, PO Box 65, Viikinkaari 1, FI-00014 Helsinki, Finland.
authors: Norbertas
authors: N
authors: Noreika
authors: Department of Bioscience, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark; Department of Bioscience, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark.
authors: Natalia E L
authors: NE
authors: Madsen
authors: Department of Bioscience, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark; Department of Entomology, North Carolina State University, Gardner Hall, Raleigh, NC 27695-7613, USA.
authors: Kim
authors: K
authors: Jensen
authors: Department of Bioscience, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark. Electronic address: soeren.toft@bios.au.dk.
authors: Søren
authors: S
authors: Toft
mesh_terms: D000821:Animal Feed; D000818:Animals; D001823:Body Composition; D001517:Coleoptera / Q000254:growth & development / Q000502:physiology*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D004435:Eating; D002149:Energy Intake; D005260:Female; D006605:Hibernation; D008055:Lipids / Q000008:administration & dosage*; D008297:Male; D015999:Multivariate Analysis; D012737:Sex Factors
chemical_list: D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D008055:Lipids
keywords: Carabidae; Carnivore diet; Energetic requirements; Geometric Framework; Non-protein energy; Nutrient balancing; Nutrient utilization; Post-hibernation recovery; Predator diet; Specific nutrients