Tydemania Weber Bosse, 1901

Holotype species: Tydemania expeditionis Weber Bosse

Original publication and holotype designation: Weber-van Bosse, A. (1901). Études sur les algues de l'Archipel Malaisien. (III). Annales du Jardin Botanique de Buitenzorg 17: 126-141, pls XVII-XIX.

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Description: Thallus large or minute, and calcified (aragonitic morph), the commoner species (or life form) consisting of a series of almost contiguous glomeruli arising in whorls from a single or branched monosiphonous main axis or stolon composed of a single large siphon. Axis to ca. 400-450 µm diameter. Glomeruli, to 3 cm. or more in diameter, are composed of relatively finer, di- to tetrachotomously branched tapering siphons. Small, monostromatic flabella, ca. 1-1.8 cm. long, of laterally connate dichotomous siphons sometimes replace basal glomeruli. Thalli of other species or morph composed solely of flabellae strung on the monosiphonous axis. Glomeruliferous thallus grows to at least 20 cm. in length, but probably to more than a meter, with growth continuous as in Halimeda and Caulerpa; flabellate form to ca. 5 cm. Fine rhizoidal siphons, produced at intervals along main axis, anchor both types of thalli. It seems likely that the flabellate species is an environmental form of glomeruli-bearing species. Elysia spp., a genus of opisthobranch mollusk graze Tydemania, presumably feeding on its plastids. Similar relationships have been established with other bryopsidalean algae such as Codium and Halimeda. Asexual reproduction is by fragmentation. Sexual reproduction involves holocarpy, i.e. essentially entire contents of siphons are released into gametangia during their formation, with thallus dying thereafter. Gametangia are unspecialized siphons; isogametes, concentrated in siphons of glomeruli, are released in early morning.

Information contributed by: L. Hillis. The most recent alteration to this page was made on 2022-02-28 by M.D. 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: Cremen, C.M., Leliaert, F., West, J.[A.], Lam, D.W., Shimada, S. Lopez-Bautista, J.M. & Verbruggen, H. (2019). Reassessment of the classification of Bryopsidales (Chlorophyta) based on chloroplast phylogenomic analyses. Molecular Phylogenetics and Evolution 130: 397-405, 2 figs.

Comments: Geographical distribution is Indo-Pacific, and essentially tropical. Glomeruliferous form commonly sprawls over and around coral rock in lagoons of coralgal reefs, where the genus may be the predominant alga of some communities. Although Tydemania has been considered a "deep water" species, its vertical range extends from about -1 m. to at least -65 m., with abundance, at some sites, increasing below about -8 m. In the lagoon of Enewetak Atoll, however, lush patches have been observed at -3 to -5 m., and extensive areas of pinnacles are festooned with it at about -8 m. At Enewetak Tydemania was not found on the outside of the atoll. Nonetheless, there, and probably elsewhere in the Marshall Islands, Tydemania ranks second to Halimeda as a carbonate producer. Flabellate forms develop as flattish caespitose patches; their known distribution is from sea level to -40m

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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=41060

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 28 February 2022. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024