THE RECLASSIFICATION OF PFIESTERIA SHUMWAYAE (DINOPHYCEAE): PSEUDOPFIESTERIA, GEN. NOV.¹

Abstract

Pfiesteria shumwayae Glasgow et Burkholder is assigned to a new genus Pseudopfiesteria gen. nov. Plate tabulation differences between Pfiesteria and Pseudopfiesteria gen. nov. as well as a maximum likelihood phylogenetic analysis based on rDNA sequence data warrant creation of this new genus. The Kofoidian thecal plate formula for the new genus is Po, cp, X, 4 0 , 1a, 6 0 0 , 6c, PC, 5 þ s, 5 0 0 0 , 0p, 2 0 0 0 0 . In addition to having six precingular plates, P. shumwayae comb. nov. also has a distinctive diamond or rectangular-shaped anterior intercalary plate. Both Pfiesteria and Pseudopfiesteria gen. nov. are reassigned to the order Peridiniales based on an apical pore complex (APC) with a canal (X) plate that contacts a symmetrical 1 0 , four to five sulcal plates, and the conservative hypothecal tabulation of 5 0 0 0 , 0p, and 2 0 0 0 0 . These morphological characters and the life histories of Pfiesteria and Pseudopfiesteria are consistent with placement of both genera in the Peridiniales. Based on the plate tabulations for P. shumwayae, P. piscicida, and the closely related ''cryptoperidiniopsoid'' and ''lucy'' groups, the family Pfiesteriaceae is amended to include species with the following tabulation: 4-5 0 , 0-2a, 5-6 0 0 , 6c, PC, 5 þ s, 5 0 0 0 , 0p, and 2 0 0 0 0 as well as an APC containing a pore plate (Po), a closing plate (cp), and an X plate; the tabulation is expanded to increase the number of sulcal plates and to include a new plate, the peduncle cover (PC) plate. Members of the family have typical dinoflagellate life cycles characterized by a biflagellated free-living motile stage, a varying number of cyst stages, and the absence of multiple amoeboid stages.Pfiesteria and Pfiesteria-like species are morphologically similar thinly armored dinoflagellates with flagellated stages characterized by their distinct Kofoidian thecal plate formulae or plate tabulations. Currently, the plate formula of the genus Pfiesteria is characterized 1

Feeding by heterotrophic dinoflagellates on the common marine heterotrophic nanoflagellate Cafeteria sp.

“…The data on the abundances of O. marina and HNFs (2 to 5 μm in size) used in this estimation were obtained from water samples collected from solar salterns near Shiwha, Korea (in 2006), while those for G. cf. guttula (plus G. dominans) and HNFs (2 to 5 μm in size) were obtained from the water samples taken in Masan Bay, Korea (in 2004 and2005). For this estimation, we assumed that the ingestion rates of O. marina and G. cf.…”

“…They have also been found to participate in reciprocal predator-prey interactions with mixotrophic dinoflagellates (Jeong et al 1997). Recently several HTD species such as Pfiesteria piscicida, Pseudopfiesteria shumwayae, Stoeckeria algicida, and Luciella masanensis (previously Lucy) have been newly discovered (Steidinger et al 1996, Litaker et al 2005, Jeong et al 2005b, Mason et al 2007). These heterotrophic dinoflagellates are harmful to finfish and shellfish due to their feeding on the blood cells and flesh of fish.…”

Feeding by protists and copepods on the heterotrophic dinoflagellates Pfiesteria piscicida, Stoeckeria algicida, and Luciella masanensis

“…However, recently, several new species in this family have been discovered (Jeong et al 2005b, Litaker et al 2005, Mason et al 2007). The present study suggests that species in this family may have a distinct ecological niches and may be differentiated from each other based on their prey species, differential growth and ingestion rates (Lin et al 2004, Jeong et al 2005a, 2007a as well as the differential mortality rate due to predation as shown in the present study.…”

“…Since the small heterotrophic dinoflagellate Pfiesteria piscicida (order Peridiniales and family Pfiesteriaceae) was first discovered in the early 1990s (Steidinger et al 1996), several more dinoflagellate species in the family Pfiesteriaceae, such as Cryptoperidiniopsis brodyi, Luciella atlantis, L. masanensis, Pseudopfiesteria shumwayae, and Stoeckeria algicida, have been discovered (Jeong et al 2005b, Litaker et al 2005, Steidinger et al 2006, Mason et al 2007). Both scientists and the public have paid attention to these dinoflagellates because some of the species are harmful to fish , Glasgow et al 2001, shellfish (Springer et al 2002, Shumway et al 2006, and humans (Schmechel & Koltai 2001).…”

Geographic distribution ofPfiesteriaspp. (Pfiesteriaceae) in Tasman Bay and Canterbury, New Zealand (2002–03)

“…Pfiesteria shumwayae Glasgow et Burkholder (Glasgow et al 2001a) (also Pseudopfiesteria shumwayae (Glasgow et Burkholder) Litaker Mason Shields et Tester) (Litaker et al 2005) and the closely related P. piscicida Steidinger et Burkholder (Steidinger et al 1996) have been detected in New Zealand sediment and seawater samples by species specific PCR-based DNA probes (targeted at ribosomal DNA). Pfiesteria shumwayae has been detected in water and sediment samples collected from Kaipara Harbour (Northland), Golden and Tasman Bays (Nelson), Havelock (Marlborough), Wairewa/Lake Forsyth, Te Waihora/Lake Ellesmere and Muriwai/Coopers Lagoon (Canterbury), and the New River Estuary (Southland); one strain isolated from Tasman Bay sediments was tested for ichthyotoxicity and proved positive .…”