Chlorokybus

Chlorokybus
	Chlorokybus atmophyticus
Scientific classification
Clade:	Viridiplantae
(unranked):	Charophyta
Class:	Chlorokybophyceae; Irisarri & al.
Order:	Chlorokybales; Irisarri & al.
Family:	Chlorokybaceae; Irisarri & al.
Genus:	Chlorokybus; Geitler
Species
	Chlorokybus atmophyticus Geitler ; Chlorokybus bremeri Irisarri et al. ; Chlorokybus cerffii Irisarri et al. ; Chlorokybus melkonianii Irisarri et al. ; Chlorokybus riethii Irisarri et al. ;

Chlorokybus is a multicellular (sarcinoid) genus of basal green algae or charophyte. It has been classified as the sole member of the family Chlorokybaceae,^[3] which is the sole member of the order Chlorokybales,^[4] in turn the sole member of the class Chlorokybophyceae.^[5]^[6] It grows on soil and rock surfaces,^[7] and is rare.^[8]

Description

Chlorokybus is a microalga forming sarcinoid, cubical packets of two to eight cells. Each cell contains a single chloroplast which contains a central pyrenoid surrounded by grains of starch, as well as another pyrenoid (called the pseudopyrenoid) near the edge of the chloroplast which lacks starch grains. Mature packets produce a layer of mucilage surrounding the cells.^[7]

Chlorokybus reproduces asexually by forming autospores. The autospores can also differentiate into zoospores, which have two flagella. Zoospores can form groups of up to 32 cells. Zoospores swim to a new location and then settle, retracting their flagella and creating a new vegetative cell.^[7]

Taxonomy

Chlorokybus atmophyticus was once thought to be the only species in the genus.^[8] In 2021, a study showed that there were at least four other species, morphologically indistinguishable, but with deep genomic differences, suggesting divergences possibly about 76 million years ago. Chlorokybus has been found in Eurasia, Central and South America.^[7]

Chlorokybus was placed in a new class, order and family. The new class Chlorokybophyceae was basal within the charophytes.^[7]

Mesostigmatophyceae

	Spirotaenia

	Chlorokybophyceae

Klebsormidiophyceae

Charophyceae

Coleochaetophyceae

	Zygnematophyceae

	Embryophyta

Within the genus, the species were related as shown in the cladogram:^[7]

Chlorokybus

C. cerffii

C. riethii

C. bremeri

	C. atmophyticus

	C. melkonianii

References

^ ^a ^b Guiry, M.D.; Guiry, G.M. "Chlorokybus". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.
^ Geitler, L. (1942). "Morphologie, Entwicklungsgeschichte und systematik neuer bemerkenswerter atmosphytischer Algen aus Wien". Flora NF. Vol. 136. pp. 1–29.
^ ^a ^b Guiry, M.D.; Guiry, G.M. "Chlorokybaceae". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.
^ ^a ^b Guiry, M.D.; Guiry, G.M. "Chlorokybales". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.
^ ^a ^b Guiry, M.D.; Guiry, G.M. "Chlorokybophyceae". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.
^ Leliaert, Frederik; Verbruggen, Heroen; Zechman, Frederick W. (2011). "Into the deep: New discoveries at the base of the green plant phylogeny". BioEssays. 33 (9): 683–692. doi:10.1002/bies.201100035. ISSN 0265-9247. PMID 21744372. S2CID 40459076.
^ ^a ^b ^c ^d ^e ^f Irisarri, Iker; Darienko, Tatyana; Pröschold, Thomas; Fürst-Jansen, Janine M. R.; Jamy, Mahwash & de Vries, Jan (2021). "Unexpected cryptic species among streptophyte algae most distant to land plants". Proceedings of the Royal Society B: Biological Sciences. 288 (1963): 20212168. doi:10.1098/rspb.2021.2168. PMC 8611356. PMID 34814752.
^ ^a ^b Rogers, Catherine E.; Mattox, Karl R.; Stewart, Kenneth D. (1980). "The Zoospore of Chlorokybus Atmophyticus, a Charophyte with Sarcinoid Growth Habit". American Journal of Botany. 67 (5): 774–783. doi:10.1002/j.1537-2197.1980.tb07706.x. JSTOR 2442669.

External links

The Delwiche Lab: Molecular Systematics

[AB_g44534-1] Guiry, M.D.; Guiry, G.M. "Chlorokybus". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.

[Geitler-2] Geitler, L. (1942). "Morphologie, Entwicklungsgeschichte und systematik neuer bemerkenswerter atmosphytischer Algen aus Wien". Flora NF. Vol. 136. pp. 1–29.

[AB_t117368-3] Guiry, M.D.; Guiry, G.M. "Chlorokybaceae". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.

[AB_t117367-4] Guiry, M.D.; Guiry, G.M. "Chlorokybales". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.

[AB_t17366-5] Guiry, M.D.; Guiry, G.M. "Chlorokybophyceae". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.

[LeliaertVerbruggen2011-6] Leliaert, Frederik; Verbruggen, Heroen; Zechman, Frederick W. (2011). "Into the deep: New discoveries at the base of the green plant phylogeny". BioEssays. 33 (9): 683–692. doi:10.1002/bies.201100035. ISSN 0265-9247. PMID 21744372. S2CID 40459076.

[IrisDariProsFurs21-7] ^ ^a ^b ^c ^d ^e ^f Irisarri, Iker; Darienko, Tatyana; Pröschold, Thomas; Fürst-Jansen, Janine M. R.; Jamy, Mahwash & de Vries, Jan (2021). "Unexpected cryptic species among streptophyte algae most distant to land plants". Proceedings of the Royal Society B: Biological Sciences. 288 (1963): 20212168. doi:10.1098/rspb.2021.2168. PMC 8611356. PMID 34814752.

[Rogers-8] Rogers, Catherine E.; Mattox, Karl R.; Stewart, Kenneth D. (1980). "The Zoospore of Chlorokybus Atmophyticus, a Charophyte with Sarcinoid Growth Habit". American Journal of Botany. 67 (5): 774–783. doi:10.1002/j.1537-2197.1980.tb07706.x. JSTOR 2442669.

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