Dysmorphococcus H.Takeda, 1916

Holotype species: Dysmorphococcus variabilis H.Takeda

Original publication and holotype designation: Takeda, H. (1916). Dysmorphococcus variabilis, gen. et sp. nov. Annals of Botany 30: 151-156.

Description: Unicellular,biflagellate and uninucleate algae with protoplast contained within a firm,globose to ellipsoid lorica. Lorica slightly compressed and brown to verydark brown resulting from iron deposits. Lorica with fine pores,appearing granulate and occasionally ornamented otherwise. Flagellaanterior emerging from separate openings in apical papilla. Protoplastglobose to pyriform, not completely filling the lorica. Contractilevacuoles either two at base of flagella or several, irregularly distributedthroughout cytoplasm.Asexualreproduction by division into 2 or 4 daughter cells released afterfragmentation of mother cell lorica. When released, daughter cells do not have distinct lorica. Aplanospores reported. Sexual reproduction unknown.Unicellular,biflagellate and uninucleate algae with protoplast contained within a firm,globose to ellipsoid lorica. Lorica slightly compressed and brown to verydark brown resulting from iron deposits. Lorica with fine pores,appearing granulate and occasionally ornamented otherwise. Flagellaanterior emerging from separate openings in apical papilla. Protoplastglobose to pyriform, not completely filling the lorica. Contractilevacuoles either two at base of flagella or several, irregularly distributedthroughout cytoplasm.Asexualreproduction by division into 2 or 4 daughter cells released afterfragmentation of mother cell lorica. When released, daughter cells do not have distinct lorica. Aplanospores reported. Sexual reproduction unknown.

Information contributed by: G.E. Dillard. The most recent alteration to this page was made on 2022-11-23 by M.D. Guiry.

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

Most recent taxonomic treatment adopted: Masjuk, N.P., Lilitska, G.G. & Kapustin, D.O. (2011). Chlamydomonadales. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, P.M., Wasser, S.P. & Nevo, E. Eds), pp. 157-218. Ruggell: A.R.A. Gantner Verlag K.-G..

Comments: Dysmorphococcus spp. cosmopolitan in distribution and frequentlyencountered in freshwater phytoplankton, although rarely observed inabundance. The eight well described species differentiated based onnumber of pyrenoids and cntractile vacuoles present, the shape of the lorica,and the nature of ornamentation of the lorica (see Ettl 1983a for descriptionsand figures. A number of Dysmorphococcus spp. previouslyconsidered as species of Chlamydomonas or Thorakomonas.Dysmorphococcus> spp. grow well under aerobic conditions in thelight. However, in axenic culture aerobic growth is inhibited in mediasupplemented with propionate, cysteine, glutamic acid (@ 5 x10-4 M), histidineand phenylalanine. Acetate supports only slight growth under aerobicconditions in the dark. No growth occurs in anaerobic conditions in thedark, though anaerobic growth in the light occurred in mdium supplementedwith -ketoglutarate, pyruvate, and acetate. Good rowthrecovery obtained in some carbon supplemented media after several weeks ofincubation in the dark. However, citrate, alanine, propionate,asparagine, cysteine, histidine, lysine and glutamic acid at some cncentration,inhibited the recovery of dark-incubated cultures. InDysmorphococcus globosus lorica formation results from the following 1)secretion of immature envelope consisting of outer fibrous layer and innergranular layer; 2) sequential precipitation of mineralized component in innerlayer, during which time pores form; 3) exudation of mucilaginous materialsthrough these pores; and 4) localized secretion and subsequent retention ofsecretory product giving rise to pebbled appearance of lorica surface.Acetolysis of aplanospores suggests presence of sporopollenin in D. globosus.

Verification of Data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.

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=43457

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 23 November 2022. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 02 December 2024