Date of Award
2016
Degree Type
Thesis
Degree Name
Master of Science in Oceanography
Specialization
Biological Oceanography
Department
Oceanography
First Advisor
Susanne Menden-Deuer
Abstract
We measured growth and grazing rates of three heterotrophic dinoflagellate species Oxyrrhis marina, Gyrodinium dominans and G. spirale exposed to starved versus continuously-fed prey conditions and assessed their starvation survival ability. All three dinoflagellate species survived long periods (>10 days) without prey, up to 118 days in the case of O. marina. After 1-3 weeks, starvation led to a 17-57% decrease in grazer cell volume and cells became more deformed and transparent over time. Starved grazers rapidly ingested new prey within 3 hours as evidenced by increased cell volumes of 4-17%. Grazer cultures that were starved had much lower maximum growth rates (-0.16-0.25 d-1) than continuously-fed cultures (0.18-0.55 d-1) at an equivalent prey concentration. This suggested a time lag >3 days for all heterotrophic dinoflagellate species to reach their maximum growth rate. Long survival ability coupled with immediate post-starvation ingestion may offer heterotrophic dinoflagellates an advantage over other grazers (e.g. ciliates) in the ability to exploit patchy prey. Delayed grazer population growth and ingestion after starvation has important implications on how we view predator dynamics in a prey-patchy ocean and especially at the onset of seasonal phytoplankton blooms.
Recommended Citation
Anderson, Sean, "Growth, Grazing and Starvation Survival in Three Heterotrophic Dinoflagellate Species" (2016). Open Access Master's Theses. Paper 861.
https://digitalcommons.uri.edu/theses/861
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