Pycnococcus R.R.L.Guillard, 1991

Holotype species: Pycnococcus provasolii R.R.L.Guillard

Original publication: Guillard, R.R.L., Keller, M.D., Okelly, C.J. & Floyd, G.L. (1991). Pycnococcus provasolii gen. et sp. nov., a coccoid prasinoxanthin-containing phytoplankter from the western north Atlantic and Gulf of Mexico. Journal of Phycology 27(1): 39-47.

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Description: Unicellular picoplanktonic green cells surrounded by thin wall-like structure. Cells contain a single parietal chloroplast with one or two pyrenoids invaginated by channels from the mitochondrion. Flagella lacking. A single operculum-like region present in the wall. Cells spherical, 1.5-4 _m in diameter. A flagellate stage also known, but details of the flagellar apparatus are lacking. In swimming cells the single emergent flagellum emerges anteriorly but folds back along the cell and is directed backwards. Cell division apparently by fission. Sexual reproduction unknown. This tiny unicell is presently known from the western North Atlantic and the Gulf of Mexico. In pigmentation it shows resemblance to the primitive prasinophytes and was therefore included in this class as a separate family. The very unusual pyrenoid structure, with an invagination from the mitochondrion has a parallel in the scaly prasinophyte Pseudoscourfieldia. Unicellular picoplanktonic green cells surrounded by thin wall-like structure. Cells contain a single parietal chloroplast with one or two pyrenoids invaginated by channels from the mitochondrion. Flagella lacking. A single operculum-like region present in the wall. Cells spherical, 1.5-4 _m in diameter. A flagellate stage also known, but details of the flagellar apparatus are lacking. In swimming cells the single emergent flagellum emerges anteriorly but folds back along the cell and is directed backwards. Cell division apparently by fission. Sexual reproduction unknown. This tiny unicell is presently known from the western North Atlantic and the Gulf of Mexico. In pigmentation it shows resemblance to the primitive prasinophytes and was therefore included in this class as a separate family. The very unusual pyrenoid structure, with an invagination from the mitochondrion has a parallel in the scaly prasinophyte Pseudoscourfieldia.

Information contributed by: Ø. Moestrup. The most recent alteration to this page was made on 2012-02-24 by Wendy Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Most recent taxonomic treatment adopted: Throndsen, J. (1996). The planktonic marine flagellates. In: Identifying marine phytoplankton. (Tomas, C.R. Eds), pp. 591-730. San Diego: Academic Press.

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Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=44987

Citing AlgaeBase
Cite this record as:
Wendy Guiry in Guiry, M.D. & Guiry, G.M. 24 February 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 16 April 2024