TY  - JOUR
A1  - Lukas, Marcus
A1  - Wacker, Alexander
T1  - Acclimation to dietary shifts impacts the carbon budgets of Daphnia magna
JF  - Journal of plankton research
N2  - Daphnia responds to low availability of carbon (food quantity) or limiting concentrations of nutrients relative to carbon (C) in excess (food quality) by respectively saving or discharging C via different pathways. We investigated which kind of food limitation leads to a faster regulation in Daphnia C budgets, and whether the pre-assimilative C pathways, ingestion and faeces egestion and the post-assimilative C pathways, excretion and respiration, are regulated concurrently. Daphnia magna were exposed to dietary shifts in different food quantities or qualities; food quality was varied in terms of the essential component, cholesterol. After acclimation to the new diet ranging from 0 to 96 h, C budgets were measured by a radiotracer technique. Dietary shifts in quantity and quality caused Daphnia to quickly adjust their C budgets within 6 h, but different C pathways were affected. A shift to low food quantity reduced Daphnia respiration indicating C retention. In contrast, sudden low quality food caused increased faeces egestion to discharge excess C. Furthermore, we observed a delayed increase in excretion but no change in respiration within the time frame studied. Such time-shifted responses appear to be an appropriate means to keep the costs of physiological adjustments relatively low, which in turn would benefit Daphnia performance.
KW  - carbon pathway
KW  - cholesterol
KW  - zooplankton
KW  - food quality
KW  - food quantity
Y1  - 2014
U6  - https://doi.org/10.1093/plankt/fbu018
SN  - 0142-7873
SN  - 1464-3774
VL  - 36
IS  - 3
SP  - 848
EP  - 858
PB  - Oxford Univ. Press
CY  - Oxford
ER  -