Protoperidinium oceanicum

General Dinoflagellate
Shape One long slender cone on top and two in the bottom with a noticeable divergence
Size Length 220 - 300 μm, width 150 μm
Colour Varies dependent on food
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.

Lifestyle Close


An organism that cannot convert inorganic carbon into a usable energy source. Instead, it consumes other organisms to obtain organic carbon for growth.

. Sexual/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.

Information not available
Harmful effects Information not available
Habitat Coastal and oceanic
Geographic Warm temperate to tropical waters
Seasonal Information not available
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).

31 - 36 (optimal)
Temperature 5 - 23 °C (optimal)


Peridinium divergens var. oceanicum Ostenfeld
Peridinium oceanicum Vanhoffen 1987
Protoperidinium murray (Kofoid 1907) Hernandez Becerril 1991
(EOL 2012)


Empire Eukaryota
Kingdom Protozoa
Subkingdom Biciliata
Infrakingdom Alveolata
Phylum Myzozoa
Subphylum Dinoflagellata
Class Dinophyceae
Order Peridiniales
Family Protoperidiniaceae
Genus Protoperidinium
Species P. oceanicum (Vanhoffen) Balech 1974

(Guiry and Guiry 2012)


Protoperidinium oceanicum is a heterotrophic dinoflagellate. It reproduces sexually and asexually. Cells feed by extruding their Close


In a eukaryotic cell, a gel-like substance within the cell membrane that contains all the organelles except for the nucleus.

out of their theca in the form of a Close


A semi-permanent extension of the cytoplasm used for locomotion and feeding by some flagellate protozoans.

and engulfing the prey items. Once it has absorbed the contents of the prey, it retracts itself back into its theca. This is called Close


(feeding) A mode of feeding used by some heterotrophic dinoflagellates. The dinoflagellate extrudes its cytoplasm, engulfing its food (often a cell or chain of cells). The food is digested outside the dinoflagellate's cell. The dinoflagellate then pulls its cytoplasm and its newly digested meal back inside its theca. This method of feeding allows dinoflagellates to eat food that is bigger than itself.

feeding (Menden-Deuer et al. 2005, Kraberg et al. 2010).


Protoperidinium oceanicum cell is star-shaped with one long Close


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



The apical or antapical extensions found in some armoured dinoflagellates; they contain cytoplasm, are covered in thecal plates and can be hollow or partially solid (Horner 2002).

and two long Close


Referring to the most posterior point of a cell. The opposite of apical.

horns (Horner 2012). The centre of the cell theca is round with a protrusion on each side (Horner 2012). The cell Close


(dinoflagellates) "In dinokont dinoflagellates, a furrow encircling the cell one or many times" (Horner 2002). It is also known as the girdle or transverse groove and may be located at, above, or below the midpoint of the cell with the left and right ends meeting or displaced form one another (Horner 2002). In diatoms, this term describes the collective elements of a diatom girdle: "The cingulum is made up of delicate silica bands that join the two valves of a frustule. Most diatoms possess a cingulum, although some may not" (Spaulding et al. 2010).

is narrow and has wide lists. The two antapical horns are long, tubular, pointed and divergent. The left antapical horn is a bit shorter and thinner than the right. Cells have a deep Close


"In dinokont dinoflagellates, the longitudinal area on the ventral surface that forms a furrow or depression and houses the longitudinal (trailing) flagellum" (Horner 2002).

that forms a strong indentation between the horns. The theca is Close


Resembling a net or having a pattern that resembles a net.

with spiny junctions, making it look very ornate under Close


(scanning electron microscope) A microscope which applies "a focused beam of high-energy electrons to generate a variety of signals at the surface of solid specimens" (NSF 2011).

(Evagelopoulos 2002).


Length: 220 - 300 μm
Width: 150 μm
(Horner 2002)

Similar species

It is similar to Protoperidinium claudicans. P. oceanicum is larger than P. claudicans and has a longer, thinner apical horn and divergent antapical horns (Steidinger and Tangen 1997).

Harmful effects

Information not available.


Found in coastal and oceanic waters (Smithsonian 2012).


Protoperidinium oceanicum is found in most of the world's warm temperate to tropical waters. It is not commonly seen in colder waters (Smithsonian 2012).
Information not available.

Growth conditions

Information not available.

Environmental Ranges

Depth range (m): 0 - 470
Temperature range (°C): 5.276 - 23.867
Nitrate (μmol L-1): 0.478 - 9.600
Salinity: 31.144 - 35.667
Oxygen (mL L-1): 4.813 - 7.455
Phosphate (μmol L-1): 0.136 - 1.129

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): 1.030 - 19.032
(EOL 2012)

Bloom characteristics

Information not available.


Encyclopedia of Life (EOL). 2012. Protoperidinium oceanicum (Vanhoffen) Balech 1974. Accessed 14 Mar 2012.

Evagelopoulos, A. 2002. Taxonomic notes on Protoperidinium (Peridiniales, Dinophyceae) species in the Thermaikos Bay (North Aegean Sea, Greece). Mediterranean Marine Science. 3/2: 41-54.

Guiry, M. D. and Guiry, G. M. 2012. Protoperidinium oceanicum (Vanhoffen) Balech 1974. Accessed 14 Mar 2012.

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

Menden-Deuer, S., Lessard, E. J., Satterberg, J. and Grunbaum, D. 2005. Growth rates and starvation survival of three species of the pallium-feeding, thecate dinoflagellate genus Protoperidinium. Aquatic Microbial Ecology. 41: 145-152.

Smithsonian Institution. 2012. Protoperidinium oceanicum (Vanhoffen) Balech 1974. Accessed 14 Mar 2012.

Steidinger, K. A. and Tangen, K. 1997. Dinoflagellates. In: Tomas, C. R. (ed.) Identifying Marine Phytoplankton. Academic Press, Inc., San Diego. 429.

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