Classification and Identification of Pfiesteria and Pfiesteria-Like Species

Abstract

Dinoflagellates can be classified both botanically and zoologically; however, they are typically put in the botanical division Pyrrhophyta. As a group they appear most related to the protistan ciliates and apicomplexans at the ultrastructure level. Within the Pyrrhophyta are both unarmored and armored forms of the dominant, motile flagellated stage. Unarmored dinoflagellates do not have thecal or wall plates arranged in specific series, whereas armored species have plates that vary in thickness but are specific in number and arrangement. In armored dinoflagellates, the plate pattern and tabulation is a diagnostic character at the family, subfamily, and even genus levels. In most cases, the molecular characterization of dinoflagellates confirms the taxonomy on the basis of external morphology; this has been demonstrated for several groups. Together, both genetic and morphological criteria are becoming increasingly important for the characterization, separation, and identification of dinoflagellates species. Pfiesteria and Pfiesteria-like species are thinly armored forms with motile dinospore stages characterized by their distinct plate formulae. Pfiesteria piscicida is the best-known member of the genus; however, there is at least one other species. Other genetically and morphologically related genera, now grouped under the common names of "Lucy," "Shepherd's crook," and cryptoperidiniopsoid, are being studied and described in separate works. All these other heterotrophic dinoflagellate groups, many of which are thought to be benign, co-occur in estuarine waters where Pfiesteria has been found.

Stoeckeria algicida n. gen., n. sp. (Dinophyceae) from the Coastal Waters off Southern Korea: Morphology and Small Subunit Ribosomal DNA Gene Sequence

“…The plate patterns of Pfiesteria spp. (Po, cp, X, 4′, 1a, 5″, 6c, 4s, 5′″, and 2″″) (Steidinger et al 1996), an unnamed group “Lucy” (Po, cp, X, 4′, 2a, 5″, 6c, 4s, 5′″, and 2″″) (Steidinger et al 2001), or Protoperidinium spp. Bergh (Po, 0 cp, X, 4′, 2–3a, 7″, 4c, 6s, 5′″, and 2″″) are most similar, but not identical, to that of S. algicida n. gen., n. sp.…”

Detection of the Dinozoans Pfiesteria piscicida and P. shumwayae: A Review of Detection Methods and Geographic Distribution1

“…Initial discovery and subsequent detection of P. piscicida relied on microscopic and culturing techniques (Burkholder, Glasgow, and Hobbs 1995). Definitive identification relied on SEM observation of the thecal plate structure (Glasgow et al 2001a; Steidinger et al 1996, 2001). For identification of Pfiesteria in environmental samples, a three‐step process started with light microscope observation of a water sample.…”

THE SEXUAL LIFE CYCLES OF PFIESTERIA PISCICIDA AND CRYPTOPERIDINIOPSOIDS (DINOPHYCEAE)1

“…Pfiesteria piscicida and the presently unclassified cryptoperidiniopsoids are relatively small, lightly armored, heterotrophic dinoflagellates found commonly inestuarine waters (Burkholder et al 1998, 2001a, Marshall 1999, Steidinger et al 2001, Parrow and Burkholder 2003a). Sexual stages of gamete fusion, planozygotes, and presumed zygotic cysts were reported for P. piscicida soon after its discovery (Burkholder et al 1992, Burkholder and Glasgow 1995, Steidinger et al 1996) and have also been described for cryptoperidiniopsoids (Parrow and Burkholder 2003a).…”