Rosenvingiella P.C.Silva, 1957

Holotype species: Rosenvingiella polyrhiza (Rosenvinge) P.C.Silva

Original publication: Silva, P.C. (1957). Notes on Pacific marine algae. Madroño 14: 41-51.

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Description: Plants dark green, unbranched thalli, 1-50 (-80) mm in height and to 100-175 µm diameter, growing alone in dense clumps or mixed with Prasiola spp. Thalli initially uniseriate, and either remaining so or becoming irregularly biseriate and multiseriate through parenchymatous divisions. Mature fronds often with numerous constrictions formed by one to many celled uniseriate regions. Rhizoids basal or scattered along filaments forming long projections from intercalary cells. Cells cylindrical, of varying length, appearing rectangular to quadrate to discoid in surface view, usually 10-15 µm or less in diameter. Cells uninucleate with single, axial stellate chloroplast and prominent pyrenoid. Asexual reproduction by aplanospores released from upper portions of filaments or by thallus fragmentation. Globular cysts known from some populations. In culture eggs may develop parthenogenetically into new filaments. Life history poorly understood, but sexual reproduction clearly oogamous and dioecious with meiosis supposedly occurring in the zygote. Eggs about 6 µm diameter, sperm 2-3 µm long with two apically inserted flagella. Gametes single in gametangia, these in dense clusters. Male gamete only flagellated cell; Sperm biflagellate with apically inserted flagella. Ultrastructurally, flagellar apparatus similar to Prasiola, and axonemes in both genera have 9 + 1 microtubule configuration. Male gametes in these genera indistinguishable. Chromosome numbers unknown.

Information contributed by: D.J. Garbary & M.D. Guiry. The most recent alteration to this page was made on 2012-03-05 by Wendy Guiry.

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

Comments: Rosenvingiella species are epilithic, and generally in mid to upper intertidal region or in terrestrial situations in arctic to temperate regions in both hemispheres, but absent in Antarctica; often co-occurring with Prasiola spp. or found in distinct zones above or below Prasiola in intertidal region. Prasiola and Rosenvingiella were synonymized by some authors who suggested that the latter was a developmental stage of the former. More definitive culture studies, however, confirmed their distinct status, but both genera are clearly related. Based on current understanding, life histories in the two genera differ Prasiola typically with diploid thallus and somatic meiosis, Rosenvingiella with haploid thallus and zygotic meiosis.

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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=32799

Citing AlgaeBase
Cite this record as:
Wendy Guiry in Guiry, M.D. & Guiry, G.M. 05 March 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 24 November 2024