Pedobesia MacRaild &, 1974
Holotype species: Pedobesia claviformis (J.Agardh) MacRaild & Womersley
Original publication and holotype designation: MacRaild, G.N. & Womersley, H.B.S. (1974). The morphology and reproduction of Derbesia clavaeformis (J. Agardh) DeToni (Chlorophyta). Phycologia 13: 83-93, 15 figs, 1 table.
Taxonomic status: currently recognized as a distinct genus.
Description: Thallus consists of 1) small calcified disk at least sometimes showing concentric rings, 2) uncalcified, branched, sprawling siphons and 3) clusters of uncalcified erect, clavate siphons which may appear as dense tufts. The two essentially prostrate states are interconvertible under certain conditions, and appear relatively persistent. The small disc form, which can measure to at least 1400 µm diam., has a surface ornamented with rows of numerous circular to obovate pores, and walls containing aragonitic calcium carbonate; secondary discs may overgrow older parts of thallus, forming a multi-layered encrusting structure. Fine siphons may develop from the margin of the disc. Both disc form, but more especially prostrate siphonous form produce dense clusters of erect siphons to about 6 cm. tall. The calcified phase distinguishes this genus from genera such as Derbesia and Bryopsis. Pedobesia is homoplastic; pyrenoids are absent. Reproduction by fragmentation, or by numerous stephanokontic zoospores produced in spherical to ovoid sporangia borne laterally on erect siphons, and separated from siphons by a thick refringent plug or gelatinous septum. Non-motile spores or other variations sometimes occur. Spores develop into one of the prostrate stages. Sexual reproduction is presently undiscovered; it has been suggested that the discs represent a gametophytic phase which has lost the capacity to form gametes.
Information contributed by: L. Hillis. The most recent alteration to this page was made on 29 Aug 2011 by M.D. Guiry.
Comments: Pedobesia has been reported with certainty from Australia, New Zealand, Japan, Galapagos Islands, Brazil, and the Mediterranean. Within habitat sites include shallow rocks, heavily shaded rock pools. Vertical range extends to at least -3 m on steeply sloping rock faces on exposed coasts. Distribution undoubtedly is much broader
Numbers of names and species: There are 7 species names in the database at present, of which 5 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
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Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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.
Created: 28 December 2000 by M.D. Guiry
Verified by: 29 August 2011 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=33445
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 15 November 2019.