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Onkonema

Generic name: ONKONEMA Geitler, 1933. Arch. Hydrobiol., Suppl. 12: 627.
Synonyms:
Diagnosis:
Type species: Onkonema compactum Geitler 1933
Descriptions:
Komárek & Anagnostidis (1998): Cells in pseudofilamentous colonies; thallus microscopic, irregular, periphytic, creeping over the substrate, with cells arranged into flat or three-dimensional groups (chroococcacean stages) or in short, irregular rows, enveloped by thin, firm, but confluent sheaths, or into pseudofilaments with irregular divarications; rows of cells uni- to two- or multiseriate, mainly with apical growth (e.g., with prevailing division of «terminal» cells). Cells irregular, polygonal-rounded in rows and especially at their ends elongate or more or less cylindrical, slight narrowed and rounded.
Komárek (1992): Unicellular - colonial - pseudofilamentous; thallus microscopic,irregular, periphytic, creeping on the substrate, with cells arranged into flat or three - dimensional groups (chroococcacean stages), short, irregular rows, enveloped by thin, firm, but confluent sheaths, up into pseudofilaments with irregular branching; rows of cells uni- up to two- or multiseriate, mainly with the apical growth (= prevailing division of "terminal" cells). Cells irregular, in rows and especially at their ends elongated or more or less cylindrical, slight narrowed and rounded.
Genotype differences, molecular data:
Reproduction strategies, life cycles, cell division:
Komárek & Anagnostidis (1998): Cells divide irregularly in different planes, in rows mostly perpendicular to the growth direction; sometimes successive division in several smaller cells (monocytes ?, nanocytes ?), which are liberated from thallus and serve to the reproduction. Monotypic genus.
Komárek (1992): Cells divide irregularly in different planes, in rows mostly perpendicularly to the growth direction; sometimes successive division in several smaller cells (nanocytes), which liberate from thallus and serve to the reproduction.
Ultrastructure:
Taxonomic position, higher hierarchy:
Cyanophyceae, Chroococcales, Hydrococcaceae
Notes to taxonomy, misinterpretations:
Ecology, ecophysiology, ecological significance:
Komárek (1992): The type species grows periphytic (epiphytic on other algae and cyanophytes) in warm and thermal springs in tropical countries (Indonesia - Java, Zambia).
Physiology and biochemistry:
Distribution, endemism, problematic citations:
Reference strain:
Infrageneric scheme, species concept:
List of species:
Onkonema compactum Geitler 1933
Onkonema paludosum Komárek et Komárková-Legnerová 2007
Keys:
List of stains:
Drawings:
Komárek 1992
Application technology:
Literature:
  2.1 taxonomy: Geitler 1933, Geitler & Ruttner 1935, Geitler 1942, Komárek 1992, Komárek & Anagnostidis
1998, Komárek & Komárková-Legnerová 2007
  2.2 cytomorphology:
  2.3 16S rRNA sequencing:
  2.4 biology and life cycles:
  2.5 ecology: