Taxonomy of Pfiesteria (Dinophyceae)

Abstract

The dinoflagellate species originally described as Pfiesteria shumwayae Glasgow et Burkholder, recently transferred to a new genus, Pseudopfiesteria Litaker et al., is reclassified into the redefined genus Pfiesteria Steidinger et Burkholder, as Pfiesteria shumwayae within the order Peridiniales. This change is based upon consideration of a compilation of previous and new morphological analyses and molecular phylogenetic analyses. Morphological analysis with scanning and transmission electron microscopy supports previous findings except in the sulcal area. In the cells examined, the sulcus is partly concealed by the peduncle cover plate (p.c.), which originates at the right side of the sulcus along the left side of the 6c and 5 000 plates. The fine structure of the p.c. appears similar to that of other thecal plates. The 1 00 plate can also extend slightly over the sulcus. Transmission electron microscopy revealed that Pfiesteria shumwayae can have at least six sulcal plates; the number remains uncertain and may vary. The sulcal plates of this small, delicately thecate species have not been clearly discerned by scanning electron microscopy of membranestripped and/or suture-swollen cells. The Kofoidian thecal plate formula for the genus Pfiesteria is Po, cp, X, 4 0 , la, 5-6 00 , 6c, p.c., ?s, 5 000 , 0p, 2 0000 . The monophyletic grouping of ''pfiesteria-like'' taxa within the order Peridiniales, as well as the grouping of Pfiesteria piscicida and Pfiesteria shumwayae within the same genus, is also supported by the preponderance of previous molecular evidence, and by the phylogenetic trees contributed in the present analysis. Pfiesteria appears to be closely related to as-yet informally www.elsevier.com/locate/hal Harmful Algae 5 (2006) 481-496 described cryptoperidiniopsoids and calcareous dinoflagellates such as Thoracosphaera; thus, the family classification requires revision that is beyond the scope of this study. #

Development of a Real-Time PCR Probe for Quantification of the Heterotrophic Dinoflagellate Cryptoperidiniopsis brodyi (Dinophyceae) in Environmental Samples

“…3 could be a result of intraclonal variation between rDNA loci in single C. brodyi cells, because only one clone was sequenced and the sequences were not obtained by consensus sequencing. Phylogenetic analyses of C. brodyi and other related dinoflagellates using ITS-5.8S rDNA sequences were previously described (23). When the partial ITS-based phylogram from this study was compared with the entire ITS-5.8S-based phylogram, the order of divergences among this dinoflagellate grouping differed slightly.…”

Effects of the estuarine dinoflagellate Pfiesteria shumwayae (Dinophyceae) on survival and grazing activity of several shellfish species

“…also has been reported to produce a toxin that accumulates in shellfish (James et al, 2003). P. piscicida and a closely related species, Pfiesteria shumwayae Glasgow et Burkholder (Marshall et al, 2006), have toxic strains Gordon et al, 2002;Burkholder et al, 2004Burkholder et al, , 2005Gordon and Dyer, 2005) that have been linked to fish mortalities and epizootics in estuaries of the mid-Atlantic and southeastern U.S. (Magnien et al, 2000;Burkholder et al, 2001a;Glasgow et al, 2001;Magnien, 2001). Adverse affects on fish have been associated with predation (Burkholder and Glasgow, 1997;Burkholder et al, 2001a,b;Lovko et al, 2003) as well as toxin production (Burkholder et al, 2001a(Burkholder et al, ,b, 2005Melo et al, 2001;Moeller et al, 2001).…”

Feeding preferences and grazing rates of Pfiesteria piscicida and a cryptoperidiniopsoid preying on fish blood cells and algal prey

“…It does offer the possibility that fish may comprise some component of the cryptoperidiniopsoid diet. Several other as-yet-unnamed species of heterotrophic dinoflagellates are closely related to Pfiesteria and cryptoperidiniopsoids, based on their morphological and genetic similarities (Steidinger et al, 2001;Seaborn et al, 2006;Marshall et al, 2006). These results suggest that further studies are needed to investigate the behavioral traits of species similar to Pfiesteria and their potential predatory and/or toxic activity toward fish and other estuarine prey.…”