T.A. Nerad
O.R. Anderson
P.M. Gillevet
M.T. Peglar
2004
<p><span>This study was undertaken to assess whether amoebae commonly found in mesohaline environments are in fact stages in the life cycles of </span><i>Pfiesteria</i><span> and </span><i>Pfiesteria-like</i><span> dinoflagellates. Primary isolations of amoebae and dinoflagellates were made from water and sediment samples from five tributaries of the Chesapeake Bay. Additional amoebae were also cloned from bioassay aquaria where fish mortality was attributed to </span><i>Pfiesteria</i><span>. Electron microscopy and small subunit (SSU) rRNA gene sequence analysis of these isolates clearly demonstrated that the commonly depicted amoeboid form of </span><i>Pfiesteria</i><span> is very likely a species of </span><i>Korotnevella</i><span> and is unrelated to </span><i>Pfiesteria</i><span> or </span><i>Pfiesteria</i><span>-like dinoflagellates. We have determined that the </span><i>Pfiesteria</i><span> and </span><i>Pfiesteria</i><span>-like dinoflagellates examined in this study undergo a typical homothallic life cycle without amoeboid stages. Furthermore, we have demonstrated that cloned amoebae sharing morphological characteristics described for stages in the life cycle of </span><i>Pfiesteria</i><span> do not transform into dinozoites. The strict clonal isolation and cultivation techniques used in this study substantially support the conclusion that the amoebae and some of the flagellates depicted in the life cycle of </span><i>Pfiesteria</i><span> are environmental contaminants of the </span><i>Pfiesteria</i><span> culture system and that the Ambush Predator Hypothesis needs to be rigorously reevaluated.</span></p>
application/pdf
10.1111/j.1550-7408.2004.tb00290.x
en
Wiley
Identification of amoebae implicated in the life cycle of Pfiesteria and Pfiesteria-like dinoflagellates
article