Pterygophora Ruprecht, 1852

Holotype species: Pterygophora californica Ruprecht

Original publication and holotype designation: Ruprecht, F.J. (1852). Neue oder unvöllstandig bekannte Pflanzen aus dem nördlichen Theile des Stillen Oceans. Mémoires de l'Académie Impériale des Sciences de Saint-Pétersbourg, Sixième Série, Sciences Naturelles 7: 55-82, 8 pls.

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Description: Life history diplohaplontic with alternation of large sporophyte bearing unilocular meiosporangia with paraphyses (sori) and microscopic dioecious and oogamous, heteromorphous gametophytes (for detail, see Laminaria). Haploid chromosome number is 13 (McKay 1933). Sporophyte perennial (life-span ca. 12 years), composed of holdfast with stout, branched haptera and a long erect, cylindrical to flattened, woody stipe terminating in a single lanceolate and smooth blade with median thickening. 5-10 pinnately arranged lateral blades (sporophylls) of similar size as terminal blade are borne beneath terminal blade at the transition region. Meristematic region is situated at transition zone between stipe and blade. Structure of sporophyte as in Laminaria composed of photosynthetic meristoderm, parenchymatic cortex and central medulla. Stipes with concentric rings, suggesting annual formation. Age estimation, however, only valid in cohorts of plants, not individuals (Hymanson and others 1990). Sori develop on both sides of sporophylls, at times also on terminal blade, mainly in winter. Sporophylls shed after fruiting; new sporophylls and new blade develop the following year. Approximately 10⁸-10⁹ zoospores are produced per plant per year (De Wreede 1986). They are viable for at least 4-8 days without germinating (Amsler 1985). Dispersal of zoospores in the field generally declines rapidly with distance from the adult plants, but during times of turbulent water flow (winter storms) recruitment out to 4000 m may appear (Reed and others 1988). Zoospores are both positive and negative chemotactive to several chemical nutrients (Amsler and Neushul 1989). The rate of settlement of zoospores is, however, only effected by a nutrient mixture 20-24 h after sunrise (14-18 h after release) (Amsler & Neushul 1990). In the field a minimum density of 1 zoospore/mm² is needed for successful recruitment on bare rock (Reed 1990a). There is a marked influence of plant density on survival, growth, fecundity and recruitment in natural populations showing a highly seasonal pattern (Reed 1990b). Strong seasonality of growth is also expressed by an endogenous circannual growth rhythm in experimental constant longday conditions (Léng 1990).

Information contributed by: I. Bartsch & M.D. Guiry. The most recent alteration to this page was made on 2014-06-21 by M.D. Guiry.

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

Most recent taxonomic treatment adopted: Silberfeld, T., Rousseau, F. & Reviers, B. de (2014). An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie Algologie 35(2): 117-156, 1 fig., 1 table.

Comments: Genus endemic to northeastern Pacific, growing subtidally on rocks, often as understorey kelp. Distribution from Alaska to Baja California. Survival range of sporophytes is -1.5-18°C (Léng & Freshwater 1988), whereas gametophytes survive up to 24/25_ (tom Dieck 1993).

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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=42121

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 21 June 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 19 April 2024