Heterocapsa F.Stein, 1883, nom. et typ. cons.
Original publication: Stein, F. (1883). Die naturgeschichte der arthrodelen Flagellaten. In: Der Organismus der Infusionstiere. III. Pt. 2. ( Eds), pp. 1-30. Leipzig:
Type designated in: Gottschling, M., Tillmann, U., Elbrächter, M., Kusber, W.-H. & Hopenrath, M. (2019). Glenodinium triquetrum Ehrenberg is a species not of Heterocapsa F.Stein but of Kryptoperidinium Er.Lindem (Kryptoperidiniaceae, Peridiniales). Phytotaxa 391(2): 155-158, 2 figs.
Description: Medium-sized (20-40 µm) biflagellated thecate dinoflagellates irregularly spindle-shaped or ovoid with a medium and circular cingulum; sulcus restricted to the hypocone. The plate pattern is difficult to establish and has been disputed. The formula published by Balech (1988a) is: Po, 4, 2a, 7", 6c, 4s, 5'",2"". As in Cachonina, body scales are present in a single layer on the cell surface external to the thecal plates. Numerous chloroplasts and an ovoid nucleus. Cell division takes place in the flagellated stage, with the theca of the mother cell shared by both daughter cells. Sexual reproduction not observed. The lipid fraction contains 24-methylcholesterol, 4,24-dimethylcholestanol, dihydrodinosterol besides cholesterol, the latter present in all dinoflagellates. H. triquetra may form dense blooms with several million cells per liter, causing discoloration in coastal waters. Fish kills related to Heterocapsa blooms apparently are not due to toxicity but rather to oversaturation of the water with oxygen during day time or oxygen deficiency during the decomposition phase. Heterocapsa shows vertical migration over 10 m and more during day-night cycle. Swimming velocity is about 100 _m S-1. Growth rates are up to about 0.7 divisions per day. Marine plankton, worldwide distribution mainly in coastal waters.
Information contributed by: M. Elbrächter. The most recent alteration to this page was made on 2023-05-26 by E.A. Molinari Novoa.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Gender: This genus name is currently treated as feminine.
Most recent taxonomic treatment adopted: Gottschling, M., Tillmann, U., Elbrächter, M., Kusber, W.-H. & Hopenrath, M. (2019). Glenodinium triquetrum Ehrenberg is a species not of Heterocapsa F.Stein but of Kryptoperidinium Er.Lindem (Kryptoperidiniaceae, Peridiniales). Phytotaxa 391(2): 155-158, 2 figs.
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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=43347
Cite this record as:
E.A. Molinari Novoa in Guiry, M.D. & Guiry, G.M. 26 May 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 30 November 2023