Umezakia M.Watanabe, 1987

Holotype species: Umezakia natans M.Watanabe

Currently accepted name for the type species: Umezakia ovalisporum (Forti) McGregor, Sendall, Niiyama, Tuji & Willis

Original publication and holotype designation: Watanabe, M. (1987). Studies on the planktonic blue-green algae 2. Umezakia natans gen. et sp. nov. (Stigonemataceae) from the Mikata lakes, Fukui Prefecture. Bulletin of the National Science Museum Series B (Botany) 13: 81-88.

Description: Filamentous; filaments solitary, free floating, in young stages isopolar, later branched, without diversified basal parts, straight or slightly curved. Young trichomes uniseriate, isopolar, not branched, more or less constricted at crosswalls, continually attenuated to the ends, with terminal cells elongated, narrow, rounded (Raphidiopsis-like stage); later stages with developing solitary intercalary heterocytes and oval akinetes, sometimes with true branching (T-type); branches initiate by the longitudinal division of the parental cell. Sheaths fine, gelatinous, wide, hyaline, diffluent (staining !). Cells cylindrical or irregular barrel-shaped, usually longer than wide, only after intense division shorter than wide, cell content pale blue-green with gas vesicles (visible aerotopes). Heterocytes occur usually scarcely (common only in nitrogen deficient environment), spherical or oval, akinetes solitary or in short irregular rows, oval, thick-walled, widely oval to almost spherical. Cells divide crosswise to the trichome axis, or longitudinally before branching. Reproduction by trichome dissociation and by akinetes. The type species was isolated from plankton of a lake in central Japan (the planktonic populations with dominant not branched trichomes can be misinterpreted as Raphidiopsis). The type culture TAC l0l is kept in Japanese algal strain collections. Umezakia is the single planktonic member of Stigonematales. Emend. Mcgregor, Sendall, Niiyama, Tujii & Willis (2023: [12]; ex-type strain: TAC101 (discontinued), material: TNS-AL-52804 in TNS.

Information contributed by: J. Komárek. The most recent alteration to this page was made on 2023-07-31 by G.M. Guiry.

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: McGregor, G.B., Sendall, B.C., Niiyama, Y., Tuji, A. & Willis, A. (2023). Chrysosporum ovalisporum is synonymous with the true-branching cyanobacterium Umezakia natans (Nostocales/Aphanizomenaceae). Journal of Phycology 59(2): 326-341.

Comments: Emend. Mc Gregor, Sendall, Niiyama, Tuji & Willis (2023: 337).

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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=47378

Citing AlgaeBase
Cite this record as:
G.M. Guiry in Guiry, M.D. & Guiry, G.M. 31 July 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 23 December 2024