Lectotype species: Derbesia marina (Lyngbye) Solier
Original publication:Solier, A.J.J. (1846). Sur deux algues zoosporées formant le nouveau genre Derbesia. Revue Botanique, Duchartre 1: 452-454.
Type designated in Solier, A.-J.-J. (1847). Sur deux algues zoosporées devant former un genre distinct, le genre Derbesia. Annales des Sciences Naturelles, Botanique, Troisième Série 7: 157-166, pl. 9.
Taxonomic status: currently recognized as a distinct genus.
Named for August Alphonse Derbès (1818-1894), French phycologist and zoologist of Marseille. - (21 Jul 2017) - M.D. Guiry
Description: Thallus of two different forms, branched siphonous phase (diploid sporophyte) of sparse to dense erect siphons, the latter sometimes appearing brush like, to about 3 (-5) cm. tall, arising from rhizoidal siphons which are perennating in at least one species; and vesicular phase (gametophyte), previously assigned to the genus Halicystis, consisting of a spherical to pyriform vesicle to over 3 cm diam., with very short and slender anchoring stalk. Main component of siphon wall, at least for some species, appears to be mannan in the branched form, and xylan in vesicular form. Sexual cycle has been considered to involve alternation of the 2 heteromorphic phases the diploid filamentous form producing stephanokontan zoospores (i.e. with ring of apical flagella) in lateral specialized sporangia separated from vegetative portions by plugs or a "double septum" near their bases. and haploid vesicular form developing biflagellate anisogametes from gametangia appearing as a transverse band within the vesicle. Gametes released forcibly through papillae which appear as white dots on vesicle wall. However, cytological examinations have shown that at least in some species, e.g. D. tenuissima, there is a haplo-heterokaryotic life cycle, with haploid gametophyte alternating with heterokaryotic sporophyte, the latter characterized by the presence of haploid nuclei from the two parents. Under these circumstances, nuclear fusion occurs in young sporangia shortly before meiosis and cleavage of zoospores. Variations include macrogametes producing new sporophytes by parthenogenesis, development of vesicular phase directly from sporangia without production of zoospores, and growth of new sporophyte from zoospores. Asexual reproduction occurs by fragmentation, and subsequent proliferation of extruded protoplasts.
Information contributed by: L. Hillis. The most recent alteration to this page was made on 29 Aug 2011 by M.D. Guiry.
Comments: Geographical distribution is global; latitudinal range extends from tropics into arctic waters. Filamentous phase is known to grow on protected stones or walls near low-tide line, and on coarse algae, shells or sponges to at least -22 m.; vesicular phase grows to at least -18 m. and may be found singly or in clusters on shaded underwater rock cliffs, in caves, under ledges, and on lithothamnioid algae.
Numbers of names and species: There are 34 species names in the database at present, as well as 1 infraspecific names. Of the species names, 20 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):
Click here to also show infraspecific names in the list below.
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=32846
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 23 September 2019.