Abstract
In this study, we address the question of how the food value of cyanobacterial carbon might be upgraded during the decay process in order to support the growth and reproduction of Daphnia. We undertook an experimental study simulating the natural decay of the cyanobacterium Microcystis over periods of 0, 2, 3, 6, and 9 days, and assessed the effects on utilization as a food source by Daphnia similoides. The results showed that the population growth rate of D. similoides increased with extent of decay of Microcystis, peaking at 3 days of decomposition and decreasing thereafter. Analyses indicate that the cumulative reproduction rate of Daphina was positive correlated with concentrations of highly unsaturated fatty acids (HUFAs) in the decaying Microcystis which are, in turn, positively correlated with biovolumes of the heterotrophic flagellate Paraphysomonas sp. Our study suggests that cyanobacterial carbon can be trophically upgraded to provide a viable food source for zooplankton by microbial food web processes in which polyunsaturated fatty acids are synthesized. Energy that cannot be transferred efficiently at the cyanobacteria-zooplankton interface may thus be channeled from decaying cyanobacterial blooms to zooplankton via microbial food webs.
| Original language | English |
|---|---|
| Pages (from-to) | 211-220 |
| Number of pages | 10 |
| Journal | Hydrobiologia |
| Volume | 743 |
| Issue number | 1 |
| Early online date | 18 Oct 2014 |
| DOIs | |
| Publication status | Published - 2015 |
Keywords
- Cyanobacterial carbon
- Zooplankton
- Microbial food webs
- Trophic upgrade
- Carbon flow
- international