Bacterivory by mixotrophic phytoflagellates

UNREIN, F.; GEREA, M.

Natal

Workshop; 18th WORKSHOP OF THE INTERNATIONAL ASSOCIATION OF PHYTOPLANKTON TAXONOMY AND ECOLOGY (IAP); 2017

INTERNATIONAL ASSOCIATION OF PHYTOPLANKTON TAXONOMY AND ECOLOGY (IAP)

Mixotrophy in algae, defined as the combination of phagotrophy and phototrophy in a single cell, is widespread among most algal groups containing flagellated species. However, mixotrophic flagellates vary widely in their ingestion capability and response to the abiotic conditions. Here, we used literature data to review the ecological strategy and impact on bacterioplankton of the different mixotrophic algal groups. We extracted information from about 50 articles, resulting in more than 500 measurements of grazing rates. The in situ cell-specific grazing rate (CSGR) of Chrysophyceae (mostly Dinobryon and Ochromonas-like species) averaged 9.5 bact./flag.h, about three times higher than any other algal class. Dictyochophyceae (Pseudopedinella), Haptophyceae (Prymnesium, Chrysochromulina) and Cryptophyceae (Cryptomonas, Plagioselmis) averaged 2-3 bact./flag.h, and dinoflagellates