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Dinoflagellate Glossary



Dinoflagellates are usually combined in one class, Dinophyceae, with a variable number of orders and many families that have fluctuating constituents as new research using electron microscopy and molecular techniques expands our understanding.  Morphological terminology of dinoflagellate cells is complex and, to a great extent, specific to dinoflagellates.

Use your mouse to rollover the terms in purple for their definitions. If this feature is not supported by your browser, please refer to the accompanying glossary for terminology. For terms not defined here, consult one or more of the following texts: Dodge (1982); Hoppenrath et al. (2009); Steidinger & Tangen (1997); Throndsen et al. (2007). All photos and drawings by Paul Hargraves, unless otherwise indicated.

Species reported from the IRL system in this list are compiled from various publications and personal observations (PE Hargraves), and fall into the following five orders as currently (2011) envisioned:

Order Prorocentrales

Cell wall with two large cellulose plates and several smaller plates in the apical flagellar area, lacking a cingulum and sulcus.

Figure 1A. General morphology of dinoflagellates from the order Prorocentrales.   Figure 1B. Scanning electron microscope (SEM) image of Prorocentrum micans from the order Prorocentrales.

Order Dinophysiales

Cells are laterally flattened with a premedian cingulum, a sulcus often with lateral extensions or lists, and a total of 18 or 19 cellulose plates.

Figure 2A. General morphology of dinoflagellates from the order Dinophysiales.   Figure 2B. Scanning electron microscope (SEM) image of Phalacroma sp. from the order Dinophysiales

Order Gonyaulacales

Cells with cingulum and sulcus, and with a series of cellulose plates organized into the following regular pattern that define the genera morphologically: apical pore complex, which typically lacks a canal plate; apical; anterior intercalary; precingular; cingular; sulcal; postcingular; posterior intercalary; antapical plates. Distinguished from the Peridiniales mostly by the arrangement and number of the thecal plates. Tabulation follows or is derived from one or both of the following patterns:

a. The first apical plate is somewhat asymmetrical, its left lateral triple junction being more anterior than the right lateral triple junction and giving a very asymmetrical pore complex; or

b. There are 2-4 fundital plates, including the posterior intercalary and first antapical plates or their homologues.

Order Peridiniales

Cells with cingulum and sulcus, and with a series of cellulose plates organized into the following regular pattern that defines the genera: apical pore complex with a canal plate; apical; anterior intercalary; precingular; cingular; sulcal; postcingular; posterior intercalary; and antapical plates. The first apical plate is usually more symmetrical than that in the Gonyaulacales.

Figure 3A. General morphology of dinoflagellates from the orders Gonyaulacales and Peridiniales.
Figure 3B. Scanning electron microscope (SEM) image of Gonyaulax sp. from the order Gonyaulacales.   Figure 3C. SEM image of Protoperidinium sp. from the order Peridiniales. Photo courtesy of FWC.

Order Gymnodiniales

Cells lack cellulose plates, but have a distinct cingulum and sulcus. Note that generic and ordinal assignments are highly flexible.

Figure 4A. General morphology of dinoflagellates from the order Gymnodiniales.   Figure 4B. Scanning electron microscope (SEM) image of Karenia brevis from the order Gymnodiniales. Photo courtesy of FWC.

IRL Dinoflagellates

The list is composed of species that have been reported as present in the IRL system in refereed publications; some require further verification. For more information on the origin and validity of names, refer to The thecate dinoflagellates are sometimes all placed in the order Gonyaulacales, or all in the order Peridiniales, and sometimes both orders are recognized as separate. The differences between orders are rather subtle and usually involve the structure of the apical pore complex and the symmetry of the first precingular plate. There is some molecular genetic evidence for the separation of orders, hence the thecate dinoflagellates are here grouped into two orders, Peridiniales and Gonyaulacales. Parasitic dinoflagellates are not included.
Several of the organisms in the following table are linked to their species profiles on the Encyclopedia of Life website. To view these profiles, click on the EOL logo to the right of the scientific name.

Prorocentrales Prorocentrum arcuatum EOL
Prorocentrales Prorocentrum balticum EOL
Prorocentrales Prorocentrum dentatum EOL
Prorocentrales Prorocentrum emarginatum EOL
Prorocentrales Prorocentrum gracile EOL
Prorocentrales Prorocentrum hoffmannianum EOL
Prorocentrales Prorocentrum lima EOL
Prorocentrales Prorocentrum mexicanum EOL
Prorocentrales Prorocentrum micans EOL
Prorocentrales Prorocentrum minimum EOL
Prorocentrales Prorocentrum scutellum EOL
Prorocentrales Prorocentrum triestinum EOL
Dinophysiales Amphisolenia bidentata EOL
Dinophysiales Amphisolenia bifurcata EOL
Dinophysiales Dinophysis argus EOL
Dinophysiales Dinophysis caudata EOL
Dinophysiales Dinophysis caudata v. acutifrons
Dinophysiales Dinophysis micropterygia EOL
Dinophysiales Dinophysis parvulum
Dinophysiales Ornithocercus magnificus EOL
Dinophysiales Oxyphysis oxytoxoides EOL
Dinophysiales Phalacroma argus EOL
Gonyaulacales Alexandrium monilatum EOL
Gonyaulacales Ceratium buceros EOL
Gonyaulacales Ceratium candelabrum EOL
Gonyaulacales Ceratium carriense EOL
Gonyaulacales Ceratium concilians EOL
Gonyaulacales Ceratium contortum EOL
Gonyaulacales Ceratium contrarium EOL
Gonyaulacales Ceratium extensum EOL
Gonyaulacales Ceratium falcatum EOL
Gonyaulacales Ceratium furca EOL
Gonyaulacales Ceratium fusus EOL
Gonyaulacales Ceratium hexacanthum EOL
Gonyaulacales Ceratium hircus EOL
Gonyaulacales Ceratium horridum EOL
Gonyaulacales Ceratium incisum EOL
Gonyaulacales Ceratium inflatum EOL
Gonyaulacales Ceratium kofoidii EOL
Gonyaulacales Ceratium lineatum EOL
Gonyaulacales Ceratium longirostrum EOL
Gonyaulacales Ceratium longissimum EOL
Gonyaulacales Ceratium lunula EOL
Gonyaulacales Ceratium macroceros EOL
Gonyaulacales Ceratium massiliense EOL
Gonyaulacales Ceratium pentagonum EOL
Gonyaulacales Ceratium ranipes EOL
Gonyaulacales Ceratium teres EOL
Gonyaulacales Ceratium trichoceros EOL
Gonyaulacales Ceratium tripos EOL
Gonyaulacales Ceratium vultur EOL
Gonyaulacales Ceratocorys horrida EOL
Gonyaulacales Coolia monotis EOL
Gonyaulacales Corythodinium tesselatum EOL
Gonyaulacales Gambierdiscus toxicus EOL
Gonyaulacales Gonyaulax apiculata EOL
Gonyaulacales Gonyaulax birostris EOL
Gonyaulacales Gonyaulax diegensis EOL
Gonyaulacales Gonyaulax digitale EOL
Gonyaulacales Gonyaulax kofoidii EOL
Gonyaulacales Gonyaulax minima EOL
Gonyaulacales Gonyaulax polygramma EOL
Gonyaulacales Gonyaulax scrippsae EOL
Gonyaulacales Gonyaulax spinifera EOL
Gonyaulacales Gonyaulax unicornis EOL
Gonyaulacales Gonyaulax verior EOL
Gonyaulacales Neoceratium belone EOL
Gonyaulacales Neoceratium bigelowii EOL
Gonyaulacales Neoceratium breve EOL
Gonyaulacales Protoceratium reticulatum EOL
Gonyaulacales Pyrocystis fusiformis EOL
Gonyaulacales Pyrocystis hamulus EOL
Gonyaulacales Pyrocystis lanceolata EOL
Gonyaulacales Pyrocystis noctiluca EOL
Gonyaulacales Pyrodinium bahamense EOL
Gonyaulacales Pyrophacus horologicum EOL
Gonyaulacales Pyrophacus steinii EOL
Peridiniales Corythodinium tesselatum EOL
Peridiniales Heterocapsa niei EOL
Peridiniales Heterocapsa rotundatum EOL
Peridiniales Kryptoperidinium foliaceum EOL
Peridiniales Oxytoxum milneri EOL
Peridiniales Peridinium aciculiferum EOL
Peridiniales Peridinium quinquecorne EOL
Peridiniales Protoperidinium abei EOL
Peridiniales Protoperidinium breve EOL
Peridiniales Protoperidinium cerasus EOL
Peridiniales Protoperidinium claudicans EOL
Peridiniales Protoperidinium conicum EOL
Peridiniales Protoperidinium crassipes EOL
Peridiniales Protoperidinium depressum EOL
Peridiniales Protoperidinium divergens EOL
Peridiniales Protoperidinium globulus EOL
Peridiniales Protoperidinium grande EOL
Peridiniales Protoperidinium hirobis EOL
Peridiniales Protoperidinium leonis EOL
Peridiniales Protoperidinium nipponicum EOL
Peridiniales Protoperidinium oceanicum EOL
Peridiniales Protoperidinium pallidum EOL
Peridiniales Protoperidinium pellucidum EOL
Peridiniales Protoperidinium pendunculatum EOL
Peridiniales Protoperidinium pentagonum EOL
Peridiniales Protoperidinium punctulatum EOL
Peridiniales Protoperidinium solidicorne EOL
Peridiniales Protoperidinium subinerme EOL
Peridiniales Protoperidinium venustum EOL
Peridiniales Scrippsiella trochoidea EOL
Gymnodiniales Akashiwo sanguinea EOL
Gymnodiniales Amphidinium carterae EOL
Gymnodiniales Amphidinium operculatum EOL
Gymnodiniales Cochlodinium citron EOL
Gymnodiniales Gymnodinium fissum EOL
Gymnodiniales Gymnodinium helveticum v. apiculata
Gymnodiniales Gymnodinium instriatum EOL
Gymnodiniales Gymnodinium pulchellum EOL
Gymnodiniales Gyrodinium dominans EOL
Gymnodiniales Gyrodinium estuariale EOL
Gymnodiniales Gyrodinium impudicum EOL
Gymnodiniales Gyrodinium instriatum EOL
Gymnodiniales Gyrodinium spirale EOL
Gymnodiniales Karenia brevis EOL
Gymnodiniales Karenia mikimotoi EOL
Gymnodiniales Karlodinium veneficum EOL
Gymnodiniales Katodinium glaucum EOL
Gymnodiniales Pheopolykrikos hartmannii EOL
Gymnodiniales Polykrikos schwartzii EOL
Gymnodiniales Takayama tasmanica EOL
Gymnodiniales Torodinium teredo EOL


Dodge, JD. 1982. Marine Dinoflagellates of the British Isles. HMSO London. 303 pp. Hoppenrath, M, Elbrächter, M & G Drebes. 2009. Marine Phytoplankton. Kleine Senckenberg Reihe 49: 1-264.

Steidinger, K & K Tangen. 1997. Dinoflagellates. 387-584. In: C Tomas (Ed.) Identifying Marine Phytoplankton. Academic Press, NY.

Throndsen, J, Hasle, GR & K Tangen. 2007. Phytoplankton of Norwegian Coastal Waters. Almater Forlag AS, Oslo. 343 pp.

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