Nutrient Balancing and Regulation

Nutrient Balancing

Researchers: Fiona Clissold, Fleur Ponton, Alison Gosby, Shawn Wilder, Mathieu Lihoreau, James Gilbert, Ximonie Clark, Tamara Pulpitel, Lindsey Gray, Samantha Solon, Kate Mcshea, Stephen Simpson

Deficits and excesses of particular macronutrients can have negative effects on the growth, reproduction and longevity of animals. As a consequence, there is strong selection for animals to regulate their intake of nutrients to a particular intake target. We are interested in examining the rules that animals use to regulate their intake of macronutrients. This can be relatively straightforward when animals have access to complementary foods that they can mix to reach their optimal intake of macronutrients. We have shown that a wide range of animals can regulate their nutrient intake including: acellular slime moulds, ants, locusts, spiders, beetles, fish, mice and mink. However, if foods are imbalanced or no choice is available, then animals may need to over-ingest or under-ingest one type of macronutrient to meet their intake target for another macronutrient. The macronutrient that is regulated versus over- or under-ingested and the degree of over- or under-ingestion can vary among animals and may depend on whether consumers are specialist vs. generalists, or herbivores vs. carnivores. Animals can also regulate their diet through postingestive processes by altering their absorbtion, assimilation or storage of nutrients. Studies of nutrient balancing regulation form the foundation of much of our other research on nutrition.

Key Publications:

  • Jensen K, Mayntz D, Toft S, Raubenheimer D, and Simpson SJ. 2011. Nutrient regulation in a predator, the wolf spider Pardosa prativaga. Animal Behaviour 81:993-999.
  • Clissold FJ, Tedder BJ, Conigrave AD, and Simpson SJ. 2010. The gastrointestinal tract as a nutrient balancing organ. Proceedings of the Royal Society B 277:1751-1759.
  • Dussutour A, Latty T, Beekman M, and Simpson SJ. 2010. Amoeboid organism solves complex nutritional challenges. Proceedings of the National Academy of Sciences, USA 107:4607-4611.
  • Dussutour A and Simpson SJ. 2009. Communal nutrition in ants. Current Biology 19:740-744.

Thermal Ecology

Researchers: Ximonie Clark, Fiona Clissold, Stephen Simpson

Temperature and nutrition interact to affect the life histories of ectotherms. Ectotherms thermoregulate to buffer the effects of environmental heterogeneity; however, as key nutritional processes differ in their thermal optima, ectotherms are often forced to prioritize the function of one process at the expense of others by varying their body temperatures. Recent research has demonstrated that when ingesting plant leaves, herbivore temperature choice, rather than altering nutritional outcomes via differences in metabolic rate, changed the rate and ratio at which protein and carbohydrate were digested and absorbed. Current research aims to gain an integrated understanding of plant–herbivore dynamics by linking the affect of herbivore body size, thermal choice and host plant use.

Key Publications:

  • Coggan N, Clissold FJ, and Simpson SJ. 2011. Locusts use dynamic thermoregulatory behaviour to optimize nutritional outcomes. Proceedings of the Royal Society B-Biological Sciences 278:2745-2752.
  • Miller GA, Clissold FJ, Mayntz D, and Simpson SJ. 2009. Speed over efficiency: locusts select body temperatures that favour growth rate over efficient nutrient utilization. Proceedings of the Royal Society B 276:3581-3589.