Paulsenella Chatton (Dinophyta), ectoparasites of marine diatoms: development and taxonomy

Abstract

All members of the dinophyte Paulsenella are ectoparasites on marine planktonic diatoms. At present three species are known, two of which are described here for the first time. The taxonomy of the type species, P. chaetoceratis, is paid critical attention. The species are clearly distinguished by their host specificity and additionally by differences in morphology, especially of the trophonts. Using clonal cultures the life cycles of the three species are compared. The vegetative development may be interrupted by formation of temporary and resting cysts. In ageing cultures, stages with nuclear cyclosis occur, believed to indicate meiosis. In P. vonstoschii, the meiospores are capable of developing into resting cysts. As yet, knowledge on sexual reproduction is still incomplete.

Five new species of the nanoflagellatePirsonia in the German Bight, North Sea, feeding on planktic diatoms

“…This was observed for the dinoflagellate Paulsenella Chatton feeding on Streptotheca thamesis Shrubsole (Drebes & Schnepf, 1982, 1988. Up to 92 % of the populations of Coscinodiscus and Palmeria have been found to be infected by the oomycete Lagenisma coscinodisci Drebes (Drebes, 1968;Grahame, 1976;Wetsteyn & Peperzak, 1991).…”

Acquired phototrophy in aquatic protists

“…The heterotrophic parasite of diatoms Paulsenella cf. chaetoceratis harvests plastids from diatom cells using a feeding tube (Drebes & Schnepf 1988) but the stability or function of these plastids are unknown.…”

Parasitic infection of the diatom Guinardia delicatula, a recurrent and ecologically important phenomenon on the New England Shelf

“…KEY WORDS: Phytoplankton · Diatom · Parasite · Imaging flow cytometry · MVCO · Guinardia delicatula · Cryothecomonas aestivalis the biology of diatom parasites has come from investigation of isolates in culture (Drebes & Schnepf 1982, 1988, Schnepf et al 1990. In contrast to the view that diatoms are typically grazed by macrozooplankton, these studies identified and described organisms that consume diatoms but are just a fraction of the size of the diatoms themselves.…”