Digestion of chlorophylls and carotenoids by the marine protozoan <i>Oxyrrhis marina</i> studied by h.p.l.c. analysis of algal pigments

Abstract

Algal pigments were measured, by reverse-phase h.p.l.c., during grazing experiments with the protozoan Oxyrrhis marina Dujardin on Rhodomonas sp. Chlorophylls and carotenoids were degraded to colourless residues; the rate of degradation of pigments was highest in the light. Very little chlorophyll a (5%) was degraded to phaeophytin and none to phaeophorbide during grazing. This suggests that phaeopigment concentrations cannot be used as a measure of algal mortality due to grazing when heterotrophic Protozoa are a component of the grazer community.