Synechococcus
| Generic name: SYNECHOCOCCUS Nägeli, 1849. Neue Denkschr. Allg. Schweiz. Ges. Gesammten Naturwiss.(Gatt. einzell. Algen) 10(7): 56. | ||||||||||
| Synonyms: ANACYSTIS Meneghini, 1837. Consp. Algol. Eugan., p. 324.[Drouet & Daily, 1956; Meneghini, Consp. Algol. Eugan., p. 324. 1837. Microcystis Unterabtheilung Anacystis Kützing, Tab. Phyc. 1: 7. 1846. Polycystis Sectio Anacystis Hansgirg, Prodr. Algenfl. Bohmen 2: 144. 1892.] LAUTERBORNIA Pringsheim 1968 incl. |
||||||||||
| Diagnosis:
Etymology: Geitler (1942): Der Name leitet sich [from Greek] von zusammenhängen und "Kern" ab. |
||||||||||
| Type species:Synechococcus elongatus Nägeli 1849. - Almost 50 described species, from which are several uncertain or synonymous.[Drouet & Daily, 1956; Type species: Anacystis marginata Menegh.] | ||||||||||
| Descriptions: Komárek & Anagnostidis (1998): Cells solitary or grouped in microscopic or macroscopic, irregular clusters, but not forming mucilaginous colonies; cells sometimes in short series of pseudofilamentous formations with 2-4 (20) cells. Mucilage absent or very fine, colourless, homogeneous, diffluent, around single cells. Cells long oval or cylindrical, sometimes several times longer than wide, straight, arcuate or sigmoid, 1.5 up to more than 20 um long and 0.4-6 (11) um wide, with parietal thylakoids; fine subunit arrays with p4 symmetry were found in few Synechococcus strains. Particularly in cultures there can arise long filamentous involution forms. Komárek (1992): Unicellular; cells live solitary or agglomerated in groups, but without common mucilage, oval, widely oval or rod-like, sometimes curved or sigmoid, rounded at the ends, with homogeneous content or with several dispersed or solitary polar granules, usually pale blue-green, rarely olive green, bright blue-green or pinkish, immotile. Without chromatic adaptation. Thylakoids localized along cells walls. Filament-like involution cells. Photoautotroph. Geitler (1942): Zellen ellipsoidisch bis zylindrisch, gerade, selten leicht gebogen, an den Enden abgerundet, einzeln oder zu zweien, nur ausnahmsweise zu vieren aneinanderhängend, ohne oder mit kaum sichtbarer, dünner Gallerthülle. Teilung quer. Zellen manchmal aktiv beweglich (Planokokken - Stadium). Geitler (1932): Zellen ellipsoidisch bis zylindrisch, gerade, an den Enden abgerundet, einzeln oder zu zweien, nur ausnahmsweise zu vieren aneinanderhängend, ohne oder mit kaum sichtbarer sehr dünner Gallerthülle. Teilung quer. Zellen manchmal beweglich (Planococcen-Stadium). |
||||||||||
| Genotype differences, molecular data: | ||||||||||
| Reproduction strategies, life cycles, cell division: Komárek & Anagnostidis (1998): Cells divide by binary fission, transversely (always in one plane in successive generations, perpendicular to the longitudinal axis) into two isomorphic or different (after asymmetric binary fission) daughter cells, which occasionally remain joined for longer period in pairs (obligatory by cleavage ?). Reproduction by cell division; (fig. 127). Komárek (1992): Cell division (pinching or cleavage) always by binary fission, perpendicular to the longer axis of the cell, i.e., in the same plane in successive generations; daughter cells grow more or less in the original size before the next division. After division the cells separate or remain arranged in short rows (pseudofilaments) of several cells, freely connected with their ends. Under suboptimal conditions arise the elongated filamentous involution cells, which are able to divide asymmetrically. Reproduction by solitary cells. |
||||||||||
| Ultrastructure: | ||||||||||
| Taxonomic position, higher hierarchy: Cyanophyceae, Chroococcales, Synechococcaceae, Synechococcoideae Notes to taxonomy, misinterpretations: Synechococcus is important experimental model organism the strains of which grow well in different types of culture equipments. To this genus belong also different strains designated commonly as Anacystis nidulans and "Agmenellum quadruplicatum" (=Synechococcus nidulans). The solitary Synechococcus cells without mucilage grow well in homogeneous liquid solutions. Among Synechococcus species occur several interesting types from ecologically extreme conditions (e.g. thermophilic Synechococcus lividus, S. bigranulatus, etc.). |
||||||||||
| Ecology, ecophysiology, ecological significance: Komárek (1992): Several species grow within mats and colonies of other algae, or form fine colonies on wet substrates (mud, wood, stones, etc.). A group of species is known from the metaphyton and periphyton of thermal and mineral springs few are described from aerophytic sites. Interesting picoplanctic or planktic species were found in oceans as well as in freswater reservoirs (lakes) (S. rhodobactron and others). The genus is surely heterogeneous and its taxonomy must be solved by help of ultrastructural procedures and by methods of molecular taxonomy. The “Marine cluster A” (with motile cells, reddish cell content, with chromatic adaptation, photoautotroph; comp. Waterbury 1989) represents evidently a special, botanically not yet revised genus. |
||||||||||
| Physiology and biochemistry: |
||||||||||
| Distribution, endemism, problematic citations: |
||||||||||
| Reference strain: |
||||||||||
| Infrageneric scheme, species concept: |
||||||||||
| List of species: Synechococcus ambiguus Skuja 1937 Synechococcus bigranulatus Skuja 1933 Synechococcus brunneolus Rabenhorst 1863 Synechococcus capitatus Bailey-Watts et Komárek 1991 Synechococcus carcerarius Norris 1967 Synechococcus endogloeicus Hindák 1995 Synechococcus endophyticus (West et West) Joosten 2006 Synechococcus elongatus (Nägeli) Nägeli 1849 Synechococcus epigloeicus Hindák 1995 Synechococcus intermedius Gradner 1927 Synechococcus marinus Jao 1948 Synechococcus mucicolus Joosten 2006 Synechococcus mundulus Skuja 1964 Synechococcus nidulans (Pringsheim) Komárek in Bourrelly 1970 Synechococcus roseo-purpureus G.S. West 1899 Synechococcus rhodobaktron Komárek et Anagnostidis 1995 Synechococcus salinarum Komárek 1956 Synechococcus sciophilus Skuja 1964 Synechococcus sigmoideus (Moore et Carter) Komárek 1970 Synechococcus subsalsus Skuja 1939 Synechococcus violaceus Grunow in Rabenhorst 1868 Unclear taxa: Excludenda: |
||||||||||
| Keys: | ||||||||||
| List of stains: | ||||||||||
Drawings: Komárek 1992 |
||||||||||
| Application technology: |
||||||||||
Literature:
|
Back to list of valid genera