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Pfiesteria
 
 
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Pfiesteria is a genus of heterotroph
Heterotroph

A heterotroph is an organism that organic compound substrates to get its Energy#Chemical energy for its life cycle. This contrasts with autotrophs such as plants which are able to directly use sources of energy such as light to produce organic substrates from inorganic carbon dioxide....
ic dinoflagellate
Dinoflagellate

The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on sea surface temperature, salinity, or depth....
s that has been associated with harmful algal bloom
Harmful algal bloom

A harmful algal bloom is a dense aggregation of phytoplankton, algae or cyanobacteria in a marine or aquatic environment that causes negative impacts to other organisms via production of natural toxins, mechanical damage to other organisms, or by other means....
s and fish kills. Pfiesteria complex organisms (PCOs) were claimed to be responsible for large fish kills in the 1980s and 1990s on the coast of North Carolina
North Carolina

North Carolina is a U.S. state located on the Atlantic Seaboard in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north....
 and in tributaries of the Chesapeake Bay
Chesapeake Bay

The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West Virginia....
. In reaction to the toxic outbreaks, six states along the US east coast initiated a monitoring program to allow for rapid response in the case of new outbreaks and to better understand the factors involved in Pfiesteria toxicity
Toxicity

Toxicity is the degree to which a substance is able to damage an exposed organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver ....
 and outbreaks.






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Encyclopedia


Pfiesteria is a genus of heterotroph
Heterotroph

A heterotroph is an organism that organic compound substrates to get its Energy#Chemical energy for its life cycle. This contrasts with autotrophs such as plants which are able to directly use sources of energy such as light to produce organic substrates from inorganic carbon dioxide....
ic dinoflagellate
Dinoflagellate

The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on sea surface temperature, salinity, or depth....
s that has been associated with harmful algal bloom
Harmful algal bloom

A harmful algal bloom is a dense aggregation of phytoplankton, algae or cyanobacteria in a marine or aquatic environment that causes negative impacts to other organisms via production of natural toxins, mechanical damage to other organisms, or by other means....
s and fish kills. Pfiesteria complex organisms (PCOs) were claimed to be responsible for large fish kills in the 1980s and 1990s on the coast of North Carolina
North Carolina

North Carolina is a U.S. state located on the Atlantic Seaboard in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north....
 and in tributaries of the Chesapeake Bay
Chesapeake Bay

The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West Virginia....
. In reaction to the toxic outbreaks, six states along the US east coast initiated a monitoring program to allow for rapid response in the case of new outbreaks and to better understand the factors involved in Pfiesteria toxicity
Toxicity

Toxicity is the degree to which a substance is able to damage an exposed organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver ....
 and outbreaks. New molecular detection methods have revealed that Pfiesteria has a worldwide distribution.

Discovery and naming

Pfiesteria was discovered in 1988 by North Carolina State University
North Carolina State University

North Carolina State University at Raleigh is a public university, coeducational, extensive research university located in Raleigh, North Carolina, United States....
 researchers JoAnn Burkholder and Ed Noga. The genus was named after Lois Ann Pfiester (1936–1992), a biologist who did much of the early research on dinoflagellates. An in-depth story of the discovery can be found in And the Waters Turned to Blood by Rodney Barker.

Feeding strategy

Early research resulted in the hypothesis that Pfiesteria acts as an "ambush predator
Ambush predator

Ambush predators or sit-and-wait predators are carnivore that capture prey by stealth or cunning, not by speed or necessarily by strength....
" and utilizes a "hit and run
Hit and run

Hit and run typically refers to:*Hit and run , the crime of failing to stop and identify oneself after a vehicular collision*Hit and run , a baseball play in which runners are in motion before the ball is hit...
" feeding strategy by releasing a toxin that paralyzes the respiratory systems of susceptible fish, such as menhaden
Menhaden

Menhaden, also known as mossbunker and pogy, are fish of the genera Brevoortia and Ethmidium, two genera of marine fish in the family Clupeidae....
, thus causing death by suffocation
Suffocation

Suffocation is the process of being Asphyxia.It may also refer to:* Suffocation , a brutal death metal band.* Suffocate, a song by the post-grunge band Finger Eleven from their 2000 album The Greyest of Blue Skies....
. It then consumes the tissue sloughed off its dead prey.

Controversy

Pfiesteria biology and the role of PCOs in killing fish and causing health issues in humans have been subject to several controversies and conflicting research results over the last few years.

  • Life cycle: Early research suggested a complex lifecycle of Pfiesteria piscicida
    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....
    , which has become controversial over the past few years due to conflicting research results, especially regarding the question whether toxic amoeboid
    Amoeboid

    Amoeboids are unicellular life-forms characterized by their similarity to amoebas....
     forms exist or not.


  • Toxicity: The hypothesis of Pfiesteria killing fish via releasing a toxin
    Toxin

    A toxin is a poisonous substance produced by living cells or organisms. For a toxic substance not produced by living organisms, "toxicant" is the more appropriate term, and "toxics" is an acceptable plural....
     in the water has been questioned as no toxin could be isolated and no toxicity was observed in some experiments. Toxicity appears to depend on the strains and assays used. In early 2007, a highly unstable toxin produced by the toxic form of Pfiesteria piscicida was identified.


  • Skin lesions: The lesions observed on fish presumed killed by Pfiesteria have been attributed to water molds by some researchers. However, it has also been established that Pfiesteria shumwayae
    Pfiesteria shumwayae

    Pfiesteria shumwayae is a heterotrophic dinoflagellate species in the genus Pfiesteria. It was first characterized in North Carolina in 2000....
     kills fish by feeding on their skin through micropredation
    Myzocytosis

    Myzocytosis is a method of feeding found in some heterotrophic organisms. It is also called "cellular vampirism" as the predatory cell pierces the cell wall and/or cell membrane of the prey cell with a feeding tube, sucks out the cellular content and digests it....
    .


  • Impact on human health: The effects of PCOs on humans have been questioned, leading to the "Pfiesteria hysteria hypothesis." A critical review of this hypothesis in the late 1990s concluded that Pfiesteria-related illness was unlikely to be caused by mass hysteria. This was corroborated by a later evaluation concluding that PCOs can cause human illness. The controversy about the risk of Pfiesteria exposure to human health is still ongoing.


In fiction

  • A fictional Pfiesteria species dangerous to humans featured in James Powlik's 1999 environmental thriller Sea Change
    Sea Change (Powlik novel)

    Sea Change is a novel by oceanographer James Powlik published in 1999. It is an environmental thriller about a harmful algal bloom....
    .
  • The fictional species Pfiesteria homicida was one of the antagonists in Frank Schätzing
    Frank Schätzing

    Frank Sch?tzing , is a German literature writer, mostly known for his best-selling science fiction novel The Swarm ....
    's 2004 novel The Swarm
    The Swarm (novel)

    The Swarm is a techno-thriller novel by German author Frank Sch?tzing. It was first published in Germany and Austria in 2004 and soon became a bestseller....
    , planned as a Hollywood movie starring Uma Thurman
    The Swarm (novel)

    The Swarm is a techno-thriller novel by German author Frank Sch?tzing. It was first published in Germany and Austria in 2004 and soon became a bestseller....
     for release in 2010.


See also

  • Predatory dinoflagellate
    Predatory dinoflagellate

    Predatory dinoflagellates are predatory heterotrophic or mixotrophic Alveolata protists that derive some or most of their nutrients from digesting other organisms....
  • Harmful algal bloom
    Harmful algal bloom

    A harmful algal bloom is a dense aggregation of phytoplankton, algae or cyanobacteria in a marine or aquatic environment that causes negative impacts to other organisms via production of natural toxins, mechanical damage to other organisms, or by other means....