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  • D A Caron
  • 1983
A new method is described that uses the fluorochrome primulin and epifluorescence microscopy for the enumeration of heterotrophic and phototrophic nanoplankton (2 to 20 mum). Phototrophic microorganisms are distinguished from heterotrophs by the red autofluorescence of chlorophyll a. Separate filter sets are used which allow visualization of the(More)
Protistan diversity was characterized at three locations in the western North Atlantic (Sargasso Sea and Gulf Stream) by sequencing 18S rRNA genes in samples from euphotic (< or = 125 m) and bathypelagic depths (2500 m). A total of 923 partial-length protistan sequences were analysed, revealing 324 distinct operational taxonomic units (OTUs) determined by(More)
The diversity of protistan assemblages has traditionally been studied using microscopy and morphological characterization, but these methods are often inadequate for ecological studies of these communities because most small protists inherently lack adequate taxonomic characters to facilitate their identification at the species level and many protistan(More)
Microplankton abundances and phytoplankton mortality rates were determined at six stations during four cruises spanning three seasons in the Ross Sea polynya, Antarctica (early spring, Oct.}Nov. 1996; mid-late summer, Jan.}Feb. 1997; fall, Apr. 1997; mid-late spring, Nov.}Dec. 1997). Rates of microzooplankton herbivory were measured using a modi"ed dilution(More)
Ostreococcus is a genus of widely distributed marine phytoplankton which are picoplanktonic in size (<2 mum) and capable of rapid growth. Although Ostreococcus has been detected around the world, little quantitative information exists on its contribution to planktonic communities. We designed and implemented a genus-specific TaqMan-based quantitative PCR(More)
single-celled, microscopic forms nearly 4 billion years ago. These minute forms constituted all life on the planet for roughly half of Earth's biological history, and microbes have remained important determinants of organic matter production , trophic transfer, and degradation throughout Earth's entire history, although more attention and research tend to(More)
The biodiversity of protistan assemblages present in microhabitats of the Ross Sea, Antarctica, was examined using molecular biological methods to obtain a greater understanding of the genetic diversity present. Sequencing of 18S clone libraries indicated genetically diverse collections of organisms in the water column, ice, and meltwater layer (slush), but(More)
Recent analyses of the small subunit ribosomal DNA (srDNA) from dinoflagellate symbionts of cnidaria have confirmed historical descriptions of a diverse but well-defined clade, Symbiodinium, as well as several other independent symbiont lineages (Rowan 1991; Rowan and Powers 1992; Sadler et al. 1992; McNally et al 1994). Dinoflagellates also occur as(More)
The mixotrophic (bacterivorous), freshwater chrysophyte Dinobryon cylindricum was cultured under a variety of light regimes and in bacterized and axenic cultures to investigate the role of phototrophy and phagotrophy for the growth of this alga. D. cylindricum was found to be an obligate phototroph. The alga was unable to survive in continuous darkness even(More)