“Will invertebrates require increasingly carbon-rich food in a warming world?”

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Thomas R. Anderson, Dag O. Hessen, Maarten Boersma, Jotaro Urabe, and Daniel J. Mayor

Invertebrate animals do not require increasingly carbon-rich food in a warming world

Calanus finmarchicus, one of the most common animals (copepods) found in the North Atlantic and northern North Sea. These tiny creatures (~2 mm) provide a crucial link in the food chain between microscopic algae and fish.
(Credit: Daniel Mayor)

Elevated temperature increases the energetic requirements (respiration) of invertebrates such as water fleas and grasshoppers. These animals should therefore require increasingly energy- (carbon-) rich food in a warming world. However, researchers challenge this idea using a mathematical model in a new study appearing in The American Naturalist. The new research shows that, because warming increases not only respiration but also the rate at which animals can collect food, optimal diet (the relative requirement for carbon versus nutrient elements) in order to prosper and grow may (contrary to expectations) change little, if at all, at higher temperatures. The carbon content of plant matter is expected to increase as the world warms, leading to a surplus of available energy. The study indicates that, during grazing, invertebrates will release some of this surplus as faeces or carbon dioxide, thereby changing the way in which these organisms interact with the global carbon cycle. Read the Article