Chroococcus

Generic name: CHROOCOCCUS Nägeli,1849. Neue Denkschr. Allg. Schweiz. Ges. Gesammten Naturwiss. 10(7): 45.
Synonyms: RHODOCOCCUS Hansgirg in Wittrock et Nordstedt, 1884. Alg. Exsicc. 14: 697.
Diagnosis:
Type species: Chroococcus rufescens (Kützing) Nägeli 1849.
Descriptions:
Komárek (1992): Unicellular - colonial; colonies usually microscopic, only few-celled, more or less spherical, rarely many-celled, forming macroscopic, gelatinous mats; colonial slime fine, diffluent, homogeneous and colourless or lamellated, limited and (rarely) coloured; around gathered cells special own envelopes, usually copying the shape of cells, homogeneous or lamellated (up to rich lamellated) [subg. Chroococcus], or the old envelopes diffluent and the cells remain distant from one another [subg. Limnococcus]. Cells rarely spherical (young reproduction cells), usually hemispherical up to irregular (often in a form of a sector of a sphere), with homogeneous or granular content, sometimes with several prominent granules visible in light microscope, pale or bright blue-green, yellowish, pinkish or violett, rarely with aerotopes (in some planktic species); sometimes (particularly in species with larger cells) with visible chromatoplasma (thylakoids are concentrated on the periphery of cells).
Geitler (1932): Zellen kugelig, nach der Teilung halbkugelig bzw. quadranten-und oktantenförmig, selten einzeln, meist zu 2, 4, seltener bis zu 16 oder noch mehr in Kolonien beisammen, mit homogenen oder geschichteten, deutlich ineinander geschachtelten, aber nicht wie bei Gloeocapsa blasig aufgetrieben und sehr deutlich gegeneinander abgegrenzten Hüllen. Bei manchen Arten (Gruppe II la) liegen mehrere Zellen in einer gemeinsamen, homogenen Gallerte. Teilungen abwechselnd nach 2 oder 3 aufeinander senkrecht stehenden Raumrichtungen; spätere Teilungswände meist schief orientiert, wenn die Tochterzellen nicht früher auseinanderfallen. Tochterzellen normalerweise zu vieren quadratisch oder würfelig gestellt, in vielzelligen Kolonien in der Regel sekundär verschoben oder durch schiefe Teilungen von Anfang an anders gelagert. Meist deutlicher Rhythmus zwischen Wachstum ohne Teilung und Teilung ohne Wachstum. Nannocytenbildung anscheinend selten.
Genotype differences, molecular data:
Reproduction strategies, life cycles, cell division:
Komárek (1992):Division of cells in three directions perpendicular each to another in first successive generations, later more or less irregular (in other directions); daughter cells grow more or less into the original size before the next division, but not always into the original shape. Daughter cells form usually soon their own gelatinous envelopes. Multiplication by the disintegration of colonies, sometimes up to solitary cells.
Ultrastructure:
Taxonomic position, higher hierarchy:
Cyanophyceae, Chroococcales, Chroococcaceae
Notes to taxonomy, misinterpretations:Variable genus; about 60 definable species from more than 120 described.
Ecology, ecophysiology, ecological significance:
Komárek (1992):Widely distributed genus in freshwaters, less in salinic localities, mainly in metaphyton of waters of different kind, also in aerophytic, thermal and soil biotopes; a group of species lives in plankton of water reservoirs (few species facultatively with aerotopes). Many species were repeatedly incorrectly identified and misinterpreted (the ecology is important for the correct determination).
Physiology and biochemistry:
Distribution, endemism, problematic
citations:
Reference strain:
Infrageneric scheme, species concept:
List of species:
Subgenus Limnococcus
Chroococcus aphanocapsoides
Skuja ex Joosten 2006
Chrococcus batavus Joosten 2006
Chroococcus catenatus Komárek et Novelo 1994
Chroococcus cronbergae Komárek et Novelo 1994
Chroococcus cumulatus Bachmann 1921
Chroococcus dispersus (Keissler) Lemmermann 1904
Chroococcus distans (G.M. Smith) Komárková-Legnerová et Cronberg 1993
Chroococcus gomontii Nygaard 1926
Chroococcus irregularis Huber 1929
Chroococcus limneticus Lemmermann 1898
Chroococcus microscopicus Komárková-Legnerová et Cronberg 1994
Chroococcus minimus (Keissler) Lemmermann 1904
Chroococcus nanoplankticus Azevedo et al. 2003
Chroococcus planctonicus Bethge 1935
Chroococcus prescottii Drouet et Daily 1942
Chroococcus purpureus Snow 1903
Chroococcus sarcinoides Huber 1929
Chroococcus sonorensis Drouet et Daily 1942
Chroococcus vacuolatus Skuja 1939

Subgenus Chroococcus
Chroococcus aeruginosus Gardner 1927
Chroococcus bernardii Van Oye 1921
Chroococcus bituminosus (Bory) Hansgirg 1892
Chroococcus calcicola Anand 1937
Chroococcus cohaerens (Brébisson) Nägeli 1849
Chroococcus constrictus Gardner 1927
Chroococcus cubicus Gardner 1927
Chroococcus deltoides Komárek et Novelo 1994
Chroococcus endophyticus Copeland 1936
Chroococcus epiphyticus Jao 1964
Chroococcus ercegovicii Komárek et Anagnostidis 1994
Chroococcus giganteus W. West 1892
Chroococcus globosus (Elenkin) Hindák 1978
Chroococcus goetzei Schmidle 1902
Cherococcus heanogloios Gardner 1927
Chroococcus helveticus Nägeli 1849
Chroococcus indicus Zeller 1873
Chroococcus kerguelensis Wille 1928
Chroococcus lithophilus Ercegović 1925
Chroococcus major Komárek et Komárková-Legnerová 2007
Chroococcus mediocris Gardner 1927
Chroococcus membraninus (Meneghini) Nägeli 1849
Chroococcus minor (Kützing) Nägeli 1849
Chroococcus minutissimus Gardner 1927
Chroococcus minutus (Kützing) Nägeli 1849
Chroococcus mipitanensis (Woloszyńska) Geitler 1925
Chroococcus molischii Schiller 1956
Chroococcus montanus Hansgirg 1892
Chroococcus multicoloratus Wood 1872
Chroococcus muralis Gardner 1927
Chroococcus mutisii Gonzalez-Guerrero 1947
Chroococcus obliteratus Richter 1886
Chroococcus occidentalis (Gardner) Komárek et Komárková-Legnerová 2007
Chroococcus pallidus (Nägeli) Nägeli 1849
Chroococcus polyedriformis Schmidle 1902
Chroococcus pulcherrimus Welch 1965
Chroococcus quaternarius Zalessky 1926
Chroococcus refractus Wood 1872
Chroococcus reeuwijkanus Joosten 2006
Chroococcus rufescens (Kützing) Nägeli 1849
Chroococcus scherffelianus Kol 1928
Chroococcus schizodermaticus W. et G.S. West 1892
Chroococcus spelaeus Ercegović 1925
Chroococcus splendidus Jao 1944
Chroococcus submarinus (Hansgirg) Kováčik 1988
Chroococcus subnudus (Hansgirg) Cronberg et Komárek 1994
Chroococcus subsphaericus Gardner 1927
Chroococcus subtilissimus Skuja 1937
Chroococcus tenacoides Copeland 1936
Chroococcus tenax(Kirchner) Hieronymus 1892
Chroococcus thermalis (Meneghini) Nägeli 1849
Chroococcus turgidus (Kützing) Nägeli 1849
Chroococcus turicensis (Nägeli) Hansgirg 1892
Chroococcus varius A. Braun in Rabenhorst 1861
Chroococcus verrucosus Krieger 1931
Chroococcus westii Boye-Petersen 1923

Unclear taxa:
Chroococcus alpinus Schmidle 1900
Chroococcus atrochalybeus Hansgirg 1892
Chroococcus aurantio-fuscus (Kützing) Rabenhorst 1865
Chroococcus auratius (Agardh) Wille 1918
Chroococcus consociatus Hariot 1891
Chroococcus crassus (Kützing) Nägeli 1849
Chroococcus decoloratus Migula 1906
Chroococcus fuscoviolaceus Hansgirg 1890
Chroococcus glomeratus  (Meneghini) Forti 1907
Chroococcus macrococcus (Kützing) Rabenhorst 1865
Chroococcus smaragdinus Hauck 1888
Chroococcus solitarius Eichler 1896
Chrococccus violaceus  Rabenhorst 1865

Keys:
List of stains:
Drawings:
Komárek (1992)
Application technology:
Literature:
  2.1 taxonomy: Geitler 1932, Potts et al. 1983, Kováčik 1988, Komárek 1992, Joosten 2006
  2.2 cytomorphology:
  2.3 16S rRNA sequencing:
  2.4 biology and life cycles:
  2.5 ecology: