A study of reproduction and other life cycle phenomena in planktonic protists using an acridine orange fluorescence technique

Abstract

The percentage of dividing individuals and temporal reproductive patterns were determined for natural populations of several planktonic protists including five species of tintinnids, a dinoflagellate, and a diatom. To obtain these data, a method was used in which the nuclei of planktonic ciliates and phytoplankters can be fluorescently stained with acridine orange at the time of collection and fixation. The technique is simple and can be used routinely in studies of reproduction or other life cycle phenomena of natural protistan populations. For the tintinnids, often more than half of the individuals were in some recognizable stage of fission; periodicity in the division process was only observed once and apparently followed a pulse of conjugation in the population. With the diatom Ditylum brightwellii the fluorescent staining technique yielded data on the extent and timing of division which were consistent with, but more complete than, previous enumerations of paired cells.

Effects of two strains of the parasitic dinoflagellate Amoebophrya on growth, photosynthesis, light absorption, and quantum yield of bloom-forming dinoflagellates

“…At each sampling period, a 7.5 ml aliquot from each flask was preserved with modified Bouin's solution (Coats & Heinbokel 1982) for estimating host abundance, and a set of 1 ml subsamples was preserved with CaCO 3 -buffered formalin (1% final conc.) for determining parasite prevalence.…”

Feeding in the mixotrophic dinoflagellate Ceratium furca is influenced by intracellular nutrient concentrations

“…C. furca was then added at a target prey:predator ratio of 1:1.5. The vials were incubated for 6 h under the same light and temperature conditions as experimental and stock cultures, and subsequently fixed with modified Bouin's solution (Coats & Heinbokel 1982). Ingestion rate was determined by placing each sample in a 5 ml Zeiss settling chamber.…”

Microphagous ciliates in mesohaline Chesapeake Bay waters: Estimates of growth rates and consumption by copepods

“…Briefly, a CTDFO2-Niskin bottle cast provided depth profiles of physical parameters and nine or ten Niskin bottles were tripped to given three or four samples each from surface, transition and bottom waters. Water was drawn from each Niskin bottle to provide samples for dissolved oxygen and chlorophyll a concentrations; whole water aliquots were preserved with glutaraldeyde for microflagellate counts and with Bouin's (Coats and Hienbokel 1982) for ciliate enumerations. The fixative, like most formalinbased solutions, likely results in cell shrinkage.…”