Control of Toxic Marine Dinoflagellate Blooms by Serial Parasitic Killers
Aurelie Chambouvet,
Pascal Morin,
Dominique Marie,
Laure Guillou*
The marine dinoflagellates commonly responsible for toxic red
tides are parasitized by other dinoflagellate species. Using
culture-independent environmental ribosomal RNA sequences and
fluorescence markers, we identified host-specific infections
among several species. Each parasitoid produces 60 to 400 offspring,
leading to extraordinarily rapid control of the host's population.
During 3 consecutive years of observation in a natural estuary,
all dinoflagellates observed were chronically infected, and
a given host species was infected by a single genetically distinct
parasite year after year. Our observations in natural ecosystems
suggest that although bloom-forming dinoflagellates may escape
control by grazing organisms, they eventually succumb to parasite
attack.
* To whom correspondence should be addressed. E-mail: lguillou{at}sb-roscoff.fr
