Description from NSF award abstract:
Species of the dinoflagellate genus Alexandrium occur around the globe, and some species, because of their toxin production, have been hypothesized to be keystone species. Alexandrium produces chemical compounds that appear to target different consumers. Neurotoxins such as PST target metazoan grazers. In preliminary experiments in their laboratory, the investigators also verified the presence of reactive oxygen species that target, at a minimum, protistan grazers. Such compounds reduce grazer fitness, and, at least in the case of PST, have been shown to have profound evolutionary effects on grazers. Grazer adaptation, in turn, can affect Alexandrium population dynamics. A common assumption is that production of toxic compounds in phytoplankton represents an adaptive defense. However, unequivocal experimental evidence in support of this hypothesis is scarce. This project will be a rigorous experimental test of the chemical defense hypothesis. The project's investigators will investigate a series of experimentally falsifiable hypotheses with both metazoan and protistan grazers challenged with Alexandrium. This project will provide novel understanding of, and insight into, the factors that determine grazer-induced toxin production, the relationship between degree of chemical defense and susceptibility to grazing, and the costs and tradeoffs of the purported mechanisms of chemical defense in Alexandrium. Verification or refutation of the chemical defense hypothesis is essential to conceptual models of the formation, control and persistence of toxic algal blooms, and chemically-mediated predator-prey interactions.
Dataset | Latest Version Date | Current State |
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Toxin content of Alexandrium catenella in response of nitrogen sources, algal alarm cues, and grazer exposure | 2021-06-16 | Final no updates expected |
Cell-growth gene expression reveals a direct fitness cost of grazer-induced toxin production in red tide dinoflagellate prey | 2021-06-16 | Final no updates expected |
A multi-phylum study of grazer-induced paralytic shellfish toxin production in the dinoflagellate Alexandrium fundyense: A new perspective on control of algal toxicity | 2021-06-16 | Final no updates expected |
Reactive oxygen species are linked to the toxicity of the dinoflagellate Alexandrium spp. to protists | 2021-06-15 | Final no updates expected |
Influence of predator-prey evolutionary history, chemical alarm-cues and feeding selection on induction of toxin production in a marine dinoflagellate | 2021-06-15 | Final no updates expected |
Principal Investigator: Hans G. Dam
University of Connecticut (UConn)
Co-Principal Investigator: David Avery
University of Connecticut (UConn)
Contact: Hans G. Dam
University of Connecticut (UConn)
Data Management Plan received by BCO-DMO on 26 June 2015. (9.62 KB)
06/29/2015