Prorocentrum gracile

General Dinoflagellate
Shape Elongated strawberry
Size Length 45 - 55 μm, width 25 - 30 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.

Two Close


The front. The part of the cell in the direction of movement. Opposite of posterior (HPP 2003).



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

Lifestyle Close


The chemical process by which light energy, water and carbon dioxide are combined to produce oxygen and organic compounds. Photoautotrophic organisms (plants and algae) use this reaction to produce their own food.

. 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 sheltered waters.
Harmful effects Not known to produce toxins.
Habitat 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).

and Close


Of or relating to estuaries.

Geographic Close


Widely distributed; occurring in many parts in the world.

in cold temperate and tropical waters
Seasonal Later 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).

< 27 (optimal)
Temperature 23 - 28 °C (optimal)


Prorocentrum diamantinae Wood 1963
Prorocentrum hentschelii Schiller 1933
Prorocentrum macrurus Athanassapaulos 1931
Prorocentrum sigmoides Bohm 1933
(Brandt 2011, Guiry and Guiry 2011)


Empire Eukaryota
Kingdom Protozoa
Subkingdom Biciliata
Infrakingdom Alveolata
Phylum Dinoflagellata
Class Dinophyceae
Order Prorocentrales
Family Prorocentraceae
Genus Prorocentrum
Species P. gracile Schutt 1895

(Guiry and Guiry 2012)


Prorocentrum gracile is a photosynthetic marine 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
(Guiry and Guiry 2012).


The Close


The back end of a cell. Opposite of anterior.

of the cell is pointed while the anterior is round (Montagnes 2006). Prorocentrum gracile has a long and strong winged Close


(axis, spine) The region of the apex or point. Refers to the most anterior point or region of the cell (HPP 2003).



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

anteriorly (Montagnes 2006, Dodge 1982). It has a kidney-shaped Close


(plural: nuclei) In eukaryotic cells, a membrane-bound organelle that contains the cell's genetic information; the nucleus controls the activities of the cell by controlling gene expression.

located posteriorly (MSIP 2012).


Length: 45 - 55 μm
Width: 25 - 30 μm
(MSIP 2012)

Similar species

Prorocentrum gracile is similar to P. micans, but P. gracile has a much longer and stronger apical spine (MSIP 2012). P. micans also has a broader body than P. gracile (LUMCON 2012).

Harmful effects

Prorocentrum gracile is not a known toxin producer. It might deplete Close


Various chemical substances that an organism needs for metabolism (i.e., to live and grow). These are usually taken up from the environment. Some examples include nitrate, phosphate, silica (for diatoms), iron, copper, etc. Some nutrients, like copper, are required for growth, but can also be toxic at high levels.

during blooms and cause Close


Describing a condition where there is no available oxygen for primary production. Oxygen may be present in complexed forms that are not available for phytoplankton. A related term is hypoxia, where oxygen is present at very low concentrations.

(Montagnes 2006).


Mainly neritic and estuarine (MSIP 2012).


Prorocentrum gracile is cosmopolitan in cold temperate to tropical waters (MSIP 2012). It has been observed in Atlantic and Pacific Ocean as well as in the Mediterranean (Dodge 1982).
Often abundant in late summer (MSIP 2012).

Growth conditions

Favoured by low salinity (< 27) and warm temperature (23 - 28 °C; Red-Tide 2012).

Environmental Ranges

Depth range (m): 0 - 50
Temperature range (°C): 10.864 - 24.625
Nitrate (μmol L-1): 1.248 - 8.908
Salinity: 31.845 - 35.145
Oxygen (mL L-1): 4.709 - 6.447
Phosphate (μmol L-1): 0.179 - 1.452

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): 3.075 - 13.782
(EOL 2012)

Bloom characteristics

Blooms in sheltered waters.


Brandt, S. 2011. Prorocentrum gracile Schutt 1895. Accessed 09 Jan 2012.

Dodge, J. D. 1982. Marine Dinoflagellates of the British Isles. Her Majesty's Stationery Office, London, UK. 303.

Encyclopedia of Life (EOL). 2012. Prorocentrum micans Ehrenberg 1883. Accessed 09 Jan 2012.

Guiry, M. D. and Guiry, G. M. 2012. Prorocentrum gracile Schutt 1895. Accessed 11 Jan 2012.

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

Louisiana University Marine Consortium (LUMCON). 2012. Prorocentrum gracile Schutt 1895. Accessed 19 Jan 2012.

Marine Species Identification Portal (MSIP). 2012. Prorocentrum gracile Schutt 1895. Accessed 15 Jan 2012.

Montagnes, D. 2006. Guide to Harmful Phytoplankton. University Of Liverpool, UK. Accessed 02 Jan 2012.

Red-Tide. 2012. Prorocentrum gracile Schutt 1895. Accessed 17 Jan 2012.

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