Acrochaete N.Pringsheim, 1862
Holotype species: Acrochaete repens Pringsheim
Currently accepted name for the type species: Ulvella repens (Pringsheim) R.Nielsen, C.J.O'Kelly & B.Wysor
Original publication and holotype designation: Pringsheim, N. (1862). Beiträge zur Morphologie der Meeres-Algen. Physikalische Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin 1862: 1-37, pls I-VIII.
Request PDFPrecise date of publication: None
Description: Plants of irregularly branched uniseriate filaments. Some species form open branched tufts, other pseudoparenchymatous, a few prostrate with a single cell layer while most are irregularly lumpy thalli. The principal feature of the genus is the formation of small hyaline cells from which a hair projects. Although not always present, they usually soon develop on actively growing plants in culture when transferred to medium low in nutrients. Vegetative cells uninucleate, containing a parietal chloroplast often with some perforations, and one to several bilenticular pyrenoids. Pigment composition typical for green algae; in addition some species have lutein or siphonaxanthin. Any vegetative cell may become a sporangium, sometimes becoming slightly larger and developing special exit papilla or exit tube. Swarmers produced after sequential division of protoplast and may be bi- or quadriflagellate zoospores or biflagellate anisogametes. Germination pattern unilateral, often leaving an evacuated spore wall; generations isomorphic. Ultrastructural studies of motile cells of an alga referred to Entocladia viridis showed the cell bodies and flagella to be without scales and wall material. The flagellar apparatus showed a counterclockwise absolute orientation. Special features were the absence of rhizoplast, and a stacked rootlet configuration. Acrochaete species very common in salt and brackish, temperate and tropical waters. as epi- and endophytes, and as part of the thin algal mat that occurs on hard substrata including animal shells, stones, and wood; a single species calcicolous. The number of species expected to increase when all species usually referred to Ectochaete, Entocladia, and Pseudodictyon have been critically studied.
Information kindly contributed by R. Nielsen but may now be outdated.
Taxonomic status: This name is currently regarded as a synonym of Ulvella.
Gender: This genus name is currently treated as feminine.
Most recent taxonomic treatment adopted: Nielsen, R., Petersen, G., Seberg, O., Daugbjerg, N., O'Kelly, C.J. & Wysor, B. (2013). Revision of the genus Ulvella (Ulvellaceae, Ulvophyceae) based on morphology and tufA gene sequences of species in culture, with Acrochaete and Pringsheimiella placed in synonymy. Phycologia 52(1): 37-56.
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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=32805
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 30 December 2015. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 21 November 2024
