Carnivorous alga

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Acute pfiesteriosis in tilapia: top = unaffected fish; bottom = fish preyed upon by the carnivorous alga Pfiesteria shumwayae
Acute pfiesteriosis in tilapia: top = unaffected fish; bottom = fish preyed upon by the carnivorous alga Pfiesteria shumwayae

Carnivorous algae are predatory or mixotrophic protists that derive nutrients from digesting animal flesh. The term has been used mainly in the news and popular media and has no scientific usage.

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[edit] Media use

The media has applied the term carnivorous or predatory algae mainly to Pfiesteria piscicida, Pfiesteria shumwayae and other Pfiesteria-like dinoflagellates implicated in harmful algal blooms and fish kills.[1][2] Pfiesteria as an "ambush predator" utilizes a "hit and run" feeding strategy by releasing a toxin that paralyzes the respiratory systems of susceptible fish, such as menhaden, thus causing death by suffocation. It then consumes the tissue sloughed off its dead prey.[3] Pfiesteria piscicida (Latin: fish killer) has been blamed for killing more than one billion fish in the Neuse and Pamlico river estuaries in North Carolina and causing skin lesions in humans in the 1990s.[2] It has been described as "skinning fish alive to feed on their flesh"[2] or chemically sensing fish and producing lethal toxins to kill their prey and feed off the decaying remains.[1] Its deadly nature has led to Pfiesteria being referred to as "killer algae"[4][5] and has earned the organism the reputation as the "T. rex of the dinoflagellate world"[6] or "the Cell from Hell."[7]

[edit] "Pfiesteria hysteria"

The prominent and exaggerating media coverage of Pfiesteria as carnivorous algae attacking fish and humans has been implicated in causing "Pfiesteria hysteria" in the Chesapeake Bay in 1997 resulting in an apparent outbreak of human illness in the Pocomoke region in Maryland.[8] However, a study published the following year concluded the symptoms were unlikely to be caused by mass hysteria.[9]

[edit] Pfiesteria as super villain

During the media coverage in the 1990s, Pfiesteria has been referred to as "super villain"[5] and subsequently has been used as such in several fictional works. A Pfiesteria subspecies killing humans featured in James Powlik's 1999 environmental thriller Sea Change. In Frank Schätzing's 2004 science fiction novel The Swarm, lobsters and crabs spread the killer alga Pfiesteria homicida to humans.

In the 2005 National Geographic TV show Extraterrestrial, the alien organism termed Hysteria combines characteristics of Pfiesteria with those of cellular slime molds. Like Pfiesteria, Hysteria is a unicellular, microscopic predator capable of producing a paralytic toxin. Like cellular slime molds, it can release chemical stress signals that cause the cells to aggregate into a swarm which allows the newly formed superorganism to feed on much larger animals and produce a fruiting body that releases spores for reproduction.[10]

[edit] Other uses

In Yann Martel's 2001 novel Life of Pi, the protagonist encounters a floating island of carnivorous algae inhabited by meerkats while shipwrecked in the Pacific Ocean. At a book reading in Calgary, Canada, Martel explained that the carnivorous algae island had the purpose of representing the more fantastical of two competing stories in his novel and challenge the reader to a "leap of faith."[11]

[edit] See also

[edit] References

  1. ^ a b AAAS Atlas of Population and Environment. Retrieved on 2008-01-05.
  2. ^ a b c Michael Greger. Bird Flu: A Virus of Our Own Hatching. Lantern Books. ISBN 1-59056-098-1. 
  3. ^ Eichhorn, Susan E.; Raven, Peter H.; Evert, Ray Franklin (2005). Biology of plants. New York: W.H. Freeman and Company, 205. ISBN 0-7167-1007-2. 
  4. ^ Cyber Diver News Network: Cell from Hell - Killer Algae Eating Fish. Retrieved on 2008-02-09.
  5. ^ a b Killer Algae. Retrieved on 2008-02-09.
  6. ^ The Fuss Over Pfiesteria. Retrieved on 2008-01-05.
  7. ^ Morris JG (1999). "Pfiesteria, "the cell from hell," and other toxic algal nightmares". Clin. Infect. Dis. 28 (6): 1191–6; quiz 1197–8. PMID 10451151. 
  8. ^ Terlizzi DE (2006). "Pfiesteria Hysteria, Agriculture, and Water Quality in the Chesapeake Bay: The Extension Bridge over Troubled Waters". Journal of Extension 44 (5): 5FEA3. 
  9. ^ Greenberg DR, Tracy JK, Grattan LM (1998). "A critical review of the Pfiesteria hysteria hypothesis". Md Med J 47 (3): 133–6. PMID 9601200. 
  10. ^ National Geographic Channel: EXTRATERRESTRIAL. Retrieved on 2008-01-05.
  11. ^ FFWD Weekly - November 20, 2003. Retrieved on 2008-01-05.