Likely Protoperidinium pentagonum, copyright Proyecto Agua.

Belongs within: Congruentidiaceae.

Protoperidinium grande
Published 31 August 2010
Protoperidinium grande, from Steidinger & Williams (1970).

Many references describe dinoflagellates as photosynthetic; this is wrong, in the same way as describing mosquitoes as feeding on blood is wrong. In terms of number of species, there are probably more non-photosynthetic than photosynthetic dinoflagellates. Protoperidinium is a genus of more than 200 species of mostly non-photosynthetic marine dinoflagellates, many of which possess a single apical horn and two antapical horns as seen in the photo above. Features distinguishing P. grande include the reticulate theca and the compressed cingular area (the cingulum is the groove around the midline; one of the dinoflagellate’s two flagella wraps around the cingulum). Unlike some other Protoperidinium species, P. grande does not produce resting cysts; as a result, it is found only in warmer waters around the world. As non-photosynthetic heterotrophs, Protoperidinium species obtain their nutrition by feeding on other micro-organisms such as diatoms, cyanobacteria or other dinoflagellates. Rather than directly engulfing their prey in the way of an amoeba, Protoperidinium extend a large pseudopodial extension called a pallium from their theca’s antapical pole to envelop it. The food organism is digested by the pallium, which is then withdrawn back into the dinoflagellate theca carrying a load of nutrients with it. This feeding behaviour was first ‘discovered’ in the late 1990s, but ironically it had actually been illustrated as long ago as 1895 with later researchers failing to recognise earlier records for what they were (Jacobson 1999*).

*Jacobson’s comment on this re-discovery are worth repeating: “the brilliant, detailed observations of Kofoid and Swezy, Schütt, and Biecheler remain a humbling reminder to those of us working in a highly capitalized, high-tech environment that important work can arise from a simple light microscope, coupled with patience, luck and the appropriate search image“.

Protoperidinium depressum feeding on diatoms, from Jacobson (1999).

Until relatively recently, Protoperidinium species were included in the genus Peridinium along with a number of freshwater dinoflagellates. The taxonomy of Recent dinoflagellates* has traditionally been dominated by a small number of what might be termed ‘super-genera’ of hundreds of species that between them encompass the great majority of living taxa. It is probably not surprising that phylogenetic analyses have suggested that many of these super-genera are polyphyletic, but most of those analyses have tended to return very poorly supported results and attempts to subdivide the super-genera have not been entirely successful. The division of Peridinium is one of the more successful examples, based on ecology (Peridinium sensu stricto is freshwater, Protoperidinium is marine), fine details of the arrangement of plates in the theca (Peridinium has five plates around the cingulum; Protoperidinium has four) and the features of cysts produced in some species (Dale 1978). Molecular analyses have supported the monophyly of Protoperidinium (Yamaguchi & Horiguchi 2005). The division on ecological grounds has been a common pattern in studies on protists; molecular analyses of a number of other micro-eukaryotic groups such as myxozoans have also produced results that contradict traditional morphological classifications but correlate strongly with ecological features.

*The taxonomy of fossil dinoflagellates is an entirely separate pot of evil.

Systematics of Protoperidinium
Protoperidinium Bergh 1881FT93 [incl. IslandiniumMS02]
|--*P. pellucidum Bergh ex Loeblich & Loeblich 1966SW70, FT93
|--P. adelienseTP87
|--P. americanumMS02
|--P. antarcticumTP87
|--P. applanatumTP87
|--P. avellanum (Meunier 1919) Balech 1974FT93 [incl. Brigantedinium cariacoenseMS02]
|--P. bipesOSS10
|--P. brochiiNMR-H99
|--P. bulbosumTP87
|--P. claudicans (Paulsen 1907) Balech 1974FT93 [incl. Votadinium spinosumMS02]
|--P. conicoides (Paulsen 1905) Balech 1974FT93 [incl. Brigantedinium simplexMS02]
|--P. conicum (Gran 1900) Balech 1974FT93 [incl. Selenopemphix quantaMS02]
|--P. crassipesNMR-H99
|--P. curtipesNMR-H99
|--P. defectumTP87
|--P. denticulatum (Gran & Braarud 1935) Balech 1974FT93
|--P. depressum (Bailey 1850) Balech 1974FT93
|--P. divaricatum (Meunier) Parke & Dodge 1976EB93 [incl. Xandarodinium xanthumMS02]
|--P. divergensNMR-H99
|--P. elegansT87
|--P. globulusGE87
|--P. grande (Kofoid 1907) Balech 1974FT93
|--P. graniiS87
|--P. islandicumTP87
|--P. latissimum (Kofoid 1907) Balech 1974FT93
|--P. leone (Pavillard 1916) Balech 1974FT93 [incl. Lejeunecysta sabrinaMS02, Quinquecuspis concretaMS02]
|--P. limbatum (Stokes) Lemmermann 1900EB93
|--P. mediocreTP87
|--P. minusculumTP87
|--P. minutum (Kofoid) Loeblich 1970S73 [=Peridinium minutumS73; incl. Pe. monospinum Paulsen 1907PA87]
|--‘Islandinium’ minutumMS02
|--P. nudum (Meunier 1919) Balech 1974FT93
|--P. oblongum (Aurivillius 1898) Balech 1974FT93 [incl. Votadinium calvumMS02]
|--P. obtusumTP87
|--P. oceanicumS87
|--P. ovatum Pouchet 1883PA87
|--P. pallidumGE87
|--P. pentagonum (Gran 1902) Balech 1974FT93 [incl. Brigantedinium majusculumMS02, Trinovantedinium applanatumMS02]
|--P. punctulatum (Paulsen 1907) Balech 1974FT93
|--P. quinquecorneLK87
|--P. saltansTP87
|--P. steidingeraeT87
|--P. steiniiS87
|--P. stellatumMS02
|--P. subinerme (Paulsen 1904) Loeblich 1970FT93 (see below for synonymy)
| |--P. s. f. subinermeS73
| |--‘Peridinium’ s. f. asymmetricum Matzenauer 1933S73
| `--‘Peridinium’ s. f. excavatum Gaarder 1954S73
`--P. thulenseTP87

Protoperidinium subinerme (Paulsen 1904) Loeblich 1970FT93 [=Peridinium subinermeS73; incl. Selenopemphix nephroides Benedek 1972EB93]

*Type species of generic name indicated


Dale, B. 1978. Acritarchous cysts of Peridinium faeroense Paulsen: implications for dinoflagellate systematics. Palynology 2: 187–193.

[EB93] Edwards, D., J. G. Baldauf, P. R. Brown, K. J. Dorning, M. Feist, L. T. Gallagher, N. Grambast-Fessard, M. B. Hart, A. J. Powell & R. Riding. 1993. ‘Algae’. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 15–40. Chapman & Hall: London.

[FT93] Fensome, R. A., F. J. R. Taylor, G. Norris, W. A. S. Sarjeant, D. I. Wharton & G. L. Williams. 1993. A classification of living and fossil dinoflagellates. Micropaleontology Special Publication 7: i–viii, 1–351.

[GE87] Gaines, G., & M. Elbrächter. 1987. Heterotrophic nutrition. In: Taylor, F. J. R. (ed.) The Biology of Dinoflagellates pp. 224–268. Blackwell Scientific.

Jacobson, D. M. 1999. A brief history of dinoflagellate feeding research. Journal of Eukaryotic Microbiology 46 (4): 376–381.

[LK87] Levandowsky, M., & P. J. Kaneta 1987. Behaviour in dinoflagellates. In: Taylor, F. J. R. (ed.) The Biology of Dinoflagellates pp. 360–397. Blackwell Scientific.

[MS02] Marret, F., & J. Scourse. 2002. Control of modern dinoflagellate cyst distribution in the Irish and Celtic seas by seasonal stratification dynamics. Marine Micropaleontology 47: 101–116.

[NMR-H99] Norén, F., Ø. Moestrup & A.-S. Rehnstam-Holm. 1999. Parvilucifera infectans Norén et Moestrup gen. et sp. nov. (Perkinsozoa phylum nov.): a parasitic flagellate capable of killing toxic microalgae. European Journal of Protistology 35: 233–254.

[OSS10] Orlova, T. Yu., I. V. Stonik & M. S. Selina. 2010. The diversity of HABs causative organisms on the Russian Pacific coast. In: China-Russia Bilateral Symposium: Proceedings of the China-Russia Bilateral Symposium of “Comparison on Marine Biodiversity in the Northwest Pacific Ocean”, 10–11 October 2010, Qingdao (China) pp. 66–70. Institute of Oceanology, Chinese Academy of Sciences; A. V. Zhirmunsky Institute of Marine Biology, Far East Branch of the Russian Academy of Sciences.

[PA87] Pfiester, L. A., & D. M. Anderson. 1987. Dinoflagellate reproduction. In: Taylor, F. J. R. (ed.) The Biology of Dinoflagellates pp. 611–648. Blackwell Scientific.

[S73] Sournia, A. 1973. Catalogue des espèces et taxons infraspécifiques de Dinoflagellés marins actuels publiés depuis la révision de J. Schiller. I. Dinoflagellés libres. Beihefte zur Nova Hedwigia 48: 1–92.

[SW70] Steidinger, K. A., & J. Williams. 1970. Dinoflagellates. Memoirs of the Hourglass Cruises 2: 1–251.

[S87] Sweeney, B. M. 1987. Bioluminescence and circadian rhythms. In: Taylor, F. J. R. (ed.) The Biology of Dinoflagellates pp. 269–281. Blackwell Scientific.

[T87] Taylor, F. J. R. 1987. Dinoflagellate morphology. In: Taylor, F. J. R. (ed.) The Biology of Dinoflagellates pp. 24–91. Blackwell Scientific.

[TP87] Taylor, F. J. R., & U. Pollingher. 1987. Ecology of dinoflagellates. In: Taylor, F. J. R. (ed.) The Biology of Dinoflagellates pp. 398–529. Blackwell Scientific.

Yamaguchi, A., & T. Horiguchi. 2005. Molecular phylogenetic study of the heterotrophic dinoflagellate genus Protoperidinium (Dinophyceae) inferred from small subunit rRNA gene sequences. Phycological Research 53 (1): 30–42.

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