Karenia brevis

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Karenia brevis
Karenia brevis

Karenia brevis

Systematics
without rank: Sar
without rank: Alveolata
without rank: Dinoflagellates (Dinoflagellata)
without rank: Dinophyceae
Genre : Karenia
Type : Karenia brevis
Scientific name
Karenia brevis
( CC Davis ) Gert Hansen & Moestrup

Karenia brevis (synonym: Gymnodinium breve or Ptychodiscus brevis ) is a unicellular, unarmored, marine dinoflagellate with a size of 20 to 40 µm in diameter. The organism is common in the Gulf of Mexico, where itregularly causes plankton bloomsoff Florida , the so-called red tides . K. brevis produces a number of poisons that aregrouped togetheras brevetoxins . These toxins can cause mass deaths in fish, birds and mammals during plankton blooms. K. brevis is photosynthetic, but does not contain peridinin .

Ecology and diffusion

K. brevis is phototactic and negatively geotactic , which means the cells swim towards the light and against gravity. The cells can reach a speed of 1 m / h. The cells are phototrophic . In the coastal waters southwest of Florida there are regular masses of K. brevis , causing the water to turn reddish in color. The Spanish navigators in the 18th century reported such red tides in this region.

proof

In order to be able to predict and possibly combat the harmful plankton blooms, the K. brevis must be carefully observed. Traditional detection methods for K. brevis are based on microscopy and pigment analysis, but these are time-consuming and require an experienced scientist. In addition, the species can be propagated in enrichment cultures and thus detected, which is also complex and time-consuming. Therefore a molecular genetic detection method based on PCR was developed.

Individual evidence

  1. ↑ Geesey, ME, and PA tester. 1993. Gymnodinium breve: ubiquitous in Gulf of Mexico waters, p. 251-256. In TJS Smayda and Shimizu (ed.), Toxic phytoplankton blooms in the sea: Proceedings of the Fifth International Conference on Toxic Marine Phytoplankton. Elsevier Science Publishing, Inc., New York, NY
  2. ↑ Kamykowski, D., EJ Milligan, and RE Reed. 1998. Relationships between geotaxis / phototaxis and the vertical migration in autotrophic dinoflagellates. J. Plankton Res. 20: 1781-1796.
  3. ↑ Aldrich, DV 1962. Photoautotrophy in Gymnodinium breve. Science 137: 988-990.
  4. ↑ Millie, DF, OM Schofield, GJ Kirkpatrick, G. Hohnsen, PA Tester, and BT Vinyard. 1997. Detection of harmful algal blooms using photopigments and absorption signatures: a case study of the Florida red tide dinoflagellate, Gymnodinium breve, Gymnodinium breve. Limnol. Oceanogr. 42: 1240-1251.
  5. ^ Gray, M., B. Wawrik, E. Caspar and JH Paul (2003). Molecular Detection and Quantification of the Red Tide Dinoflagellate Karenia brevis in the Marine Environment , Applied and Environmental Microbiology, vol. 69, 5726-5730, doi = 10.1128 / AEM.69.9.5726-5730.2003

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