Aquatic Sciences Meeting, Albuquerque 2001

SS20 Biological Control of Harmful Algal Blooms: Role of Grazers, Parasites, Viruses and Bacteria

Date: Monday, February 12, 2001, Time: 2:00:00 PM

Location: Cochiti/Taos

Coats, D, W, Smithsonian Environmental Research Center, Edgewater, USA, coats@serc.si.edu

Park, M, G, Smithsonian Environmental Research Center, Edgewater, USA, park@serc.si.edu

Cooney, S, K, Smithsonian Environmental Research Center, Edgewater, USA, cooney@serc.si.edu

PARASITISM OF BLOOM-FORMING DINOFLAGELLATES: HOST SPECIFICITY AND STRAIN VARIATION IN AMOEBOPHRYA

Top-down control of bloom-forming algae can arise from the action of eukaryotic parasites including fungi and certain flagellates. Recent work in marine systems has identified two groups of parasitic flagellates, the dinoflagellate genus Amoebophrya and the recently described species Pavilucifera infectans (Phylum Perkinsozoa), as playing important roles in the population dynamics of red-tide dinoflagellates. Both are obligate parasites and must kill their host to complete their life cycle. However, unlike P. infectans, Amoebophrya strains have a high degree of host specificity. Experiments using isolates of Amoebophrya from Gymnodinium sanguineum, Gyrodinium instriatum, and Gyrodinium galatheanum show that cross infection of parasite strains among these host is difficult to induce. Furthermore, when cross infection does occur, the parasite fails to reach maturity and does not propagate subsequent generations of parasites. Strain specific differences in infectivity, reproductive output, and survival of progeny suggest divergence in life history strategies used by Amoebophrya to contend with a parasitic life style.

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Aquatic Sciences Meeting, Albuquerque 2001

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