Lake Sanabria is a glacial lake located at 1000 m a.s.l. in NW Spain. Its water is characterised by a low content of mineral salts, rather low pH, and oligotrophic status, which are all currently viewed as being favorable for Chrysophyte growth and proliferation. The study of the phytoplankton at different depths of the water column for three years showed that Chrysophytes were one of the groups of algae less well-represented in the phytoplankton (1% and 8%, respectively, for numbers of cells and biovolume).
Ochromonas, Pseudopedinella, Mallomonas and Dinobryon were the more representative chrysophyte genera. D. cylindricum, D. divergens and D. crenulatum were some of the Dinobryon species observed. M. akrokomos, M. crassisquama and M. costata were among the most frequent Mallomonas species. Observations on the Chrysophyte cysts from samples of the lake sediment suggest that variability of representation is higher than in planktonic samples.
The maximum values of Chrysophyte biovolume were found in the nutrient-exhausted epilimnion of summer and autumn which could be related to the mixotrophic capabilities of several species.