Prorocentrum minimum

General Dinoflagellate
Shape Heart or leaf-shaped
Size Length 14 - 22 μm, width 10 - 15 μm
Colour Golden-brown
Connection None (solitary)
Covering Cellulose Close


(plural: thecae) Cell wall. In dinoflagellates, it is composed of cellulose plates within vesicles (Horner 2002).



(plural: flagella) A tail-like projection that sticks out from the cell body and enables movement.



An organelle in the cell that contains the cell pigments (Horner 2002). This is where photosynthesis occurs. A chloroplast is a specialized chromatophore.

Many golden-brown chloroplasts
Lifestyle Close


An organism that is both autotrophic (photosynthesizes or chemosynthesizes) and heterotrophic. That is, it can gain energy both from light (or chemical) energy and also by consuming other organisms. This allows such organisms to take advantage of different environmental conditions.

. Asexual.


A rapid increase or accumulation of algal populations in an aquatic system. This will likely involve one or a few dominant phytoplankton species. This follows seasonal patterns (i.e., spring, summer or fall bloom) with dominant species being those that are best adapted to the environmental conditions of that time period. Discolouration of the water may be observed because of the algae's pigmentation. Blooms are often green but may be yellow-brown or red depending on the species present.

Blooms in Close


Of or relating to estuaries.

Harmful effects Venerupin shellfish poisoning (VSP) and diarrhetic shellfish poisoning Close

Diarrhetic Shellfish Poisoning

(DSP) Mainly caused by okadaic acid, a toxin produced by some diatoms. When shellfish consume phytoplankton, they can bioconcentrate the toxin leading to non-life threatening symptoms that may include diarrhea, nausea, vomiting and cramps (Yasumoto et al. 1985).

Habitat Estuarine and Close


Describing shallow, near-shore areas and the organisms that live there. Refers to shallow marine waters ranging from the low tide mark to the continental shelf. Varying amounts of sunlight penetrate the water, allowing photosynthesis by both phytoplankton and bottom-dwelling organisms. Close proximity to land favours high nutrient content and biological activity (Encyclopedia Britannica 2011).

Geographic Cold temperate brackish water to tropical regions
Seasonal Late summer
Growth Conditions


The dissolved ion content of a body of water. Can be measured in the following units: parts per thousand (PPT or ‰), practical salinity units (PSU), and absolute salinity (g/kg). PPT is measured by weight, denoting the number of parts salt per thousand total parts or a value of 10-3. PSU measures the conductivity of saltwater and compares it in a ratio to a standard KCl solution (because this is a ratio, salinity measured in this way can also be written without units). The newest unit of salinity is absolute salinity, which uses the mass fraction of salt in seawater (g salt per kg seawater) rather than its conductivity (TEOS-20 2010).

15 (optimal)
Temperature 20 °C (optimal)


Exuviaella minima Schiller 1933
Prorocentrum triangulatum Martin 1929
Exuviaella marie-lebouriae Parke and Ballantine 1957
Prorocentrum cordiformis Bursa 1959
Prorocentrum marie-lebouriae (Parke and Ballantine 1957) Loeblich III 1970
Exuviaella minima Pavillard 1916
(Smithsonian 2011, Horner 2002)


Empire Eukaryota
Kingdom Protozoa
Subkingdom Biciliata
Infrakingdom Alveolata
Phylum Dinoflagellata
Class Dinophyceae
Order Prorocentrales
Family Prorocentraceae
Genus Prorocentrum
Species P. minimum (Pavillard) J. Schiller 1933

(Guiry and Guiry 2011)


Prorocentrum minimum is a mixotrophic dinoflagellate. It reproduces asexually by Close

Binary fission

A form of asexual reproduction where one cell divides into two identical cells. All prokaryotes and some eukaryotes reproduce in this manner. Compare with mitosis, where the nucleus must also divide, adding an extra step to the process.

binary fission
(Smithsonian 2011).


Cell shape varies from triangular to heart-shaped (sometimes leaf-shaped). It is 14 - 22 μm long and 10 - 15 μm wide with a slight depression on the wider end. Its surface is covered with very small Close


In some diatoms, "closed or solid structures projecting from the cell wall;" in dinoflagellates, solid projections that usually taper to a point.

(difficult to see in Close


(light microscopy) "Using a microscope in which a beam of light passes through optical lenses to view an image of the specimen" (MCM LTER 2010).

; Kimor et al. 1985). It has many golden-brown chloroplasts and one large Close


Any of various protein granules that can be found in the chloroplast of some algae species. It is associated with the production of starch.

(Smithsonian 2011). It has two flagella with numerous pores on them (Red-Tide 2011). It moves quickly in the water (Kimor et al. 1985).


Length: 14 - 22 μm
Width: 10 - 15 μm

Similar species

It is similar to Prorocentrum balticum but P. minimum is larger and more angular (Smithsonian 2011, Kraberg et al. 2010).

Harmful effects

Prorocentrum minimum is a toxic dinoflagellate. It causes two kinds of shellfish poisoning: venerupin shellfish poisoning (VSP) and diarrhetic shellfish poisoning (DSP; Smithsonian 2011, Witek and Plinski 2000, Grzebyk et al. 1997). VSP causes liver damage and gastrointestinal illness in humans, which can lead to death (Grzebyk et al. 1997). During blooms, this dinoflagellate can turn the water brown (Witek and Plinski 2000).


Brackish, estuarine waters such as fjords, bays and other coastal waters in temperate and tropical regions (Kimor et al. 1985).


It is a Close


Widely distributed; occurring in many parts in the world.

species that is commonly found in brakish waters in temperate to tropical regions. It is generally found in shallow, estuarine environments (Red-Tide 2011), but has also been reported in neritic regions (Steidinger and Tangen 1996). It is widely distributed in the Baltic Sea (Witek and Plinski 2000). It has also been reported in bays and fjords near Oslo during August to September (Kimor et al. 1985).
Summer, especially August and September (Smithsonian 2011).

Growth conditions

It flourishes in estuarine conditions (Witek and Plinski 2000).

Environmental Ranges

Depth range (m): 0 - 270
Temperature range (°C): -1.856 - 25.489
Nitrate (μmol L-1): 0.213 - 28.160
Salinity: 32.443 - 35.667
Oxygen (mL L-1): 4.756 - 8.359
Phosphate (μmol L-1): 0.088 - 1.935

Silicic acid

A general term to describe chemical compounds containing silicon, oxygen and hydrogen with a general formula of [SiOx(OH)4-2x]n. Diatoms polymerize silicic acid into biogenic silica to form their frustules (Azam and Chisholm 1976).

(μmol L-1): 1.245 - 59.659
(Kimor et al. 1985)

Bloom characteristics

A bloom reported in Kiel Fjord, Oslo, Norway occurred when water temperature was 19 - 22 °C and salinity was 14 - 15 (Kimor et al. 1985). This bloom was initiated by a combination of high light intensity and moderate winds (3 - 5 m s-1; Kimor et al. 1985).


Encyclopedia of Life (EOL). 2012. Prorocentrum minimum (Pavillard) J. Schiller. Accessed 20 Jan 2012.

Grzebyk, D., Denardou, A., Berland, B. and Pouchus, Y. F. 1997. Evidence of a new toxin in the red-tide dinoflagellate Prorocentrum minimum. Journal of Plankton Research. 19(8): 1111-1124.

Guiry, M. D. and Guiry, G. M. 2011. Prorocentrum minimum (Pavillard) J. Schiller 1933. Accessed 27 Nov 2011.

Horner, R. A. 2002. A Taxonomic Guide To Some Common Phytoplankton. Biopress Limited, Dorset Press, Dorchester, UK. 200.

Kimor, B., Moigis, A. G., Dohms, V. and Stienem, C. 1985. A case of mass occurrence of Prorocentrum minimum in the Kiel Fjord. Marine Ecology- Progress Series. 27(14): 209-215.

Kraberg, A., Baumann, M. and Durselen, C. D. 2010. Coastal Phytoplankton Photo Guide for Northern European Seas. Verlag Dr. Friedrich Pfeil, Munchen, Germany. 203.

Red-Tide. 2011. Prorocentrum minimum (Pavillard) J. Schiller 1933. Accessed 27 Nov 2011.

Smithsonian Institution. 2011. Prorocentrum minimum (Pavillard) J. Schiller 1933. Accessed 28 Nov 2011.

Witek. B. and Plinski, M. 2000. The first recorded bloom of Prorocentrum minimum (Pavillard) Schiller in the coastal zone of the Gulf of Gdanńsk. Oceanologia. 42(1): 29-36.

a place of mind, The Univeristy of British Columbia

UBC Department of Earth, Ocean and Atmospheric Sciences,
2020 - 2207 Main Mall, Vancouver, BC Canada V6T 1Z4.
 |  Legal |  Valid XHTML 1.0 Transitional

Emergency Procedures  | Accessibility  | Contact UBC  | © Copyright The University of British Columbia