''Pseudopfiesteria shumwayae'' (formerly placed in the genus ''Pfiesteria''; see 'Taxonomy' section below) is a species of

heterotroph A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

ic dinoflagellates in the genus '' Pseudopfiesteria.'' It was first characterized in

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

in 2000. It can acquire the ability for

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

through eating

green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

e and retaining their

chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...

s. It can also turn

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

y and toxic. Strains of ''Pseudopfiesteria shumwayae'' have been implicated in

fish kills The term fish kill, known also as fish die-off, refers to a localized die-off of fish populations which may also be associated with more generalized mortality of aquatic life.University of Florida. Gainesville, FL (2005) ''Plant Management in Fl ...

around the US east coast. ''Pseudopfiesteria shumwayae'' has been described as having a less complex life cycle than ''

Pfiesteria piscicida ''Pfiesteria piscicida'' is a dinoflagellate species of the genus '' Pfiesteria'' that some researchers claim is responsible for many harmful algal blooms in the 1980s and 1990s on the coast of North Carolina and Maryland. North Carolinian media ...

''.

Toxicity

While toxic strains of ''Pseudopfiesteria shumwayae'' have been implicated in fish kills, its ability to secrete an exotoxin to kill its prey has been subject to controversy. A study published in 2002 has shown that it is capable of killing fish by direct contact and feeding on their skin through

micropredation Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

. Toxicity levels appear to depend on the strains and assays used in the laboratory. ''Pfiesteria shumwayae'' toxin present in filtered water can cause cognitive deficits in rats.

Taxonomy

Based on 2005 research, the organism previously known as ''Pfiesteria shumwayae'' should be reassigned its own genus, based on both morphological analysis and molecular evidence as supported by rDNA analysis. Although closely resembling ''

'', it differs in two important precingular plates 5" and 6", which historically, only one plate difference would be sufficient to place in a separate genus. The species ' ''shumwayae'' ' has thus been categorized in a more recently erected genus, ''Pseudopfiesteria''.

Occurrence

''Pfiesteria'' has a worldwide distribution and is typically found in estuaries and coastal habitats. It is usually benign unless it " blooms" to a high concentration. High concentrations of ''Pseudopfiesteria shumwayae'' have been found in the following locations: * Taskinas Creek, a tributary of the York River in

James City County James City County is a county located in the Commonwealth of Virginia. As of the 2020 census, the population was 78,254. Although politically separate from the county, the county seat is the adjacent independent city of Williamsburg. Located ...

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...

, in March 2005.

References

Dinophyceae {{Improve categories, date=April 2022