The chlorarachniophytes are a small group of exclusively marine algae widely distributed in tropical and temperate waters.[3] They are typically mixotrophic, ingesting bacteria and smaller protists as well as conducting photosynthesis. Normally they have the form of small amoebae, with branching cytoplasmic extensions that capture prey and connect the cells together, forming a net. They may also form flagellatezoospores, which characteristically have a single subapical flagellum that spirals backwards around the cell body, and walled coccoid cells.
A cultured chlorarachniophyte, Lotharella globosa LEX01 strain [2]
The chloroplasts were presumably acquired by ingesting some green alga.[4] They are surrounded by four membranes, the outermost of which is continuous with the endoplasmic reticulum, and contain a small nucleomorph between the middle two, which is a remnant of the alga's nucleus. This contains a small amount of DNA and divides without forming a mitotic spindle. The origin of the chloroplasts from green algae is supported by their pigmentation, which includes chlorophyllsa and b, and by genetic similarities. The only other groups of algae that contain nucleomorphs are a few species of dinoflagellates, which also have plastids originating from green algae,[5] and the cryptomonads, which acquired their chloroplasts from a red alga.
The chlorarachniophytes only include five genera, which show some variation in their life-cycles and may lack one or two of the stages described above. Genetic studies place them among the Cercozoa, a diverse group of amoeboid and amoeboid-like[clarification needed] protozoa.
The chlorarachniophytes were placed before in the order Rhizochloridales, class Xanthophyceae (e.g., Smith, 1938), as algae, or in order Rhizochloridea, class Xanthomonadina (e.g., Deflandre, 1956), as protozoa.
So far sexual reproduction has only been reported in two species; Chlorarachnion reptans and Cryptochlora perforans.[3]
Species L. globosa (Ishida & Hara 1994) Ishida & Hara 1996 [Chlorarachnion globosum Ishida & Hara 1994]
Genus Norrisiella Ota, Ueda & Ishida 2007
Species Norrisiella sphaerica Ota, Ueda & Ishida 2007
Genus Partenskyella Ota et al. 2009
Species Partenskyella glossopodia Ota et al. 2009
Lotharella globosa extending a filopodium (Fp) through a pore of the cell wall (CW) from a walled amoeboid cell. Py: pyrenoid. Scale bar = 10µm
Binary and quaternary cell divisions of Lotharella globosa. Arrowheads indicate the parental cell wall. Scale bar = 10µm
Flagellate cell of Lotharella globosa with a single flagellum (Fl) and plastid (P) Scale bar = 10µm
Referencesedit
^Hibberd, David J.; Norris, Richard E. (1984). "Cytology and ultrastructure of Chlorarachnion reptans (Chlorarchniophyta Divisio nova, Chlorachniophyceae Classis nova)". Journal of Phycology. 20 (2): 310–330. doi:10.1111/j.0022-3646.1984.00310.x. S2CID 86059445.
^ abHirakawa; et al. (2011), "Morphological Diversity between Culture Strains of a Chlorarachniophyte, Lotharella globosa", PLOS ONE, 6 (8): e23193, Bibcode:2011PLoSO...623193H, doi:10.1371/journal.pone.0023193, PMC3156133, PMID 21858028
^ abBrodie, Juliet; Lewis, Jane (26 November 2007). Unravelling the algae: the past, present, and future of algal systematics. CRC Press. ISBN9780849379901.
^Keeling PJ (2009). "Chromalveolates and the evolution of plastids by secondary endosymbiosis". J. Eukaryot. Microbiol. 56 (1): 1–8. doi:10.1111/j.1550-7408.2008.00371.x. PMID 19335769. S2CID 34259721.
^Nakayama, Takuro; Takahashi, Kazuya; Kamikawa, Ryoma; Iwataki, Mitsunori; Inagaki, Yuji; Tanifuji, Goro (2020). "Putative genome features of relic green alga-derived nuclei in dinoflagellates and future perspectives as model organisms". Communicative and Integrative Biology. 13 (1): 84–88. doi:10.1080/19420889.2020.1776568. PMC7518460. PMID 33014260.
^M.D. Guiry (2016), "Chlorarachniophyceae [Chlorarachnea]", AlgaeBase, World-wide electronic publication, National University of Ireland, Galway, retrieved 25 October 2016
^Cavalier-Smith (2017), "Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences", Protoplasma, 255 (1): 297–357, doi:10.1007/s00709-017-1147-3, PMC5756292, PMID 28875267
External linksedit
AlgaeBase: Chlorarachniophyta
Systematic Biology: Cercozoa 2015-04-02 at the Wayback Machine
Tree of Life: Chlorarachniophyta
Wikispecies has information related to Chlorarachniophyta.
April 15, 2024
chlorarachniophyte, chlorarachniophytes, small, group, exclusively, marine, algae, widely, distributed, tropical, temperate, waters, they, typically, mixotrophic, ingesting, bacteria, smaller, protists, well, conducting, photosynthesis, normally, they, have, f. The chlorarachniophytes are a small group of exclusively marine algae widely distributed in tropical and temperate waters 3 They are typically mixotrophic ingesting bacteria and smaller protists as well as conducting photosynthesis Normally they have the form of small amoebae with branching cytoplasmic extensions that capture prey and connect the cells together forming a net They may also form flagellate zoospores which characteristically have a single subapical flagellum that spirals backwards around the cell body and walled coccoid cells ChlorarachniophytesChlorarachnion reptansScientific classificationDomain EukaryotaClade DiaphoretickesClade SARPhylum CercozoaSubphylum ReticulofilosaClass ChlorarachniophyceaeHibberd amp Norris 1984Orders amp FamiliesMinorisida Minorisidae Chlorarachniales ChlorarachniaceaeSynonymsChlorarachnea Cavalier Smith 1993 orth zool Chlorarachniophyta Hibberd amp Norris 1984 1 A cultured chlorarachniophyte Lotharella globosa LEX01 strain 2 The chloroplasts were presumably acquired by ingesting some green alga 4 They are surrounded by four membranes the outermost of which is continuous with the endoplasmic reticulum and contain a small nucleomorph between the middle two which is a remnant of the alga s nucleus This contains a small amount of DNA and divides without forming a mitotic spindle The origin of the chloroplasts from green algae is supported by their pigmentation which includes chlorophylls a and b and by genetic similarities The only other groups of algae that contain nucleomorphs are a few species of dinoflagellates which also have plastids originating from green algae 5 and the cryptomonads which acquired their chloroplasts from a red alga The chlorarachniophytes only include five genera which show some variation in their life cycles and may lack one or two of the stages described above Genetic studies place them among the Cercozoa a diverse group of amoeboid and amoeboid like clarification needed protozoa The chlorarachniophytes were placed before in the order Rhizochloridales class Xanthophyceae e g Smith 1938 as algae or in order Rhizochloridea class Xanthomonadina e g Deflandre 1956 as protozoa So far sexual reproduction has only been reported in two species Chlorarachnion reptans and Cryptochlora perforans 3 Contents 1 Phylogeny 2 Taxonomy 3 References 4 External linksPhylogeny editBased on the work of Hirakawa et al 2011 2 Chlorarachniaceae Partenskyella glossopodiaAmorphochlora amoebiformisGymnochlora stellataChlorarachnion reptansBigelowiella natansNorrisiella sphaericaLotharella L vacuolataL oceanicaL reticulosaL globosaTaxonomy editClass Chlorarachniophyceae Hibberd amp Norris 1984 6 Chlorarachnea Cavalier Smith 1998 Chlorarachniophyta Hibberd amp Norris 1984 Chlorarachnia Cavalier Smith 1993 Order Minorisida Cavalier Smith 2017 7 Family Minorisidae Cavalier Smith 2017 Genus Minorisa Del Campo 2013 Species Minorisa minuta Del Campo 2013 Order Chlorarachniales Ishida amp Hara 1996 Chlorarachniida Hibberd amp Norris 1984 Family Chlorarachniaceae Pascher 1939 Ishida amp Hara 1996 Genus Amorphochlora Ishida Yabuki amp Ota 2011 Species Amorphochlora amoebiformis Ishida amp Hara 1996 Ishida Yabuki amp Ota 2011 Lotharella amoeboformis Ishida amp Hara 1996 Genus Bigelowiella Moestrup 2001 Species B longifila Shuhei Kunihiko amp Kenichiro 2007 Species B natans Moestrup 2001 Genus Chlorarachnion Geitler 1930 Species Chlorarachnion reptans Geitler 1930 Genus Cryptochlora Calderon Saenz amp Schnetter 1987 Species Cryptochlora perforans Calderon Saenz amp Schnetter 1987 Genus Gymnochlora Ishida Nakayama amp Hara 1996 Species G dimorpha Ota 2011 Species G stellata Ishida Nakayama amp Hara 1996 Genus Lotharella Ishida amp Hara 1996 Species L scrobicolata Ishida amp Hara Species L polymorpha Dietz et al 2003 Species L vacuolata Ota amp Ishida 2005 Species L oceanica Ota 2009 Species L reticulosa Ohta 2012 Species L globosa Ishida amp Hara 1994 Ishida amp Hara 1996 Chlorarachnion globosum Ishida amp Hara 1994 Genus Norrisiella Ota Ueda amp Ishida 2007 Species Norrisiella sphaerica Ota Ueda amp Ishida 2007 Genus Partenskyella Ota et al 2009 Species Partenskyella glossopodia Ota et al 2009 nbsp Lotharella globosa extending a filopodium Fp through a pore of the cell wall CW from a walled amoeboid cell Py pyrenoid Scale bar 10µm nbsp Binary and quaternary cell divisions of Lotharella globosa Arrowheads indicate the parental cell wall Scale bar 10µm nbsp Flagellate cell of Lotharella globosa with a single flagellum Fl and plastid P Scale bar 10µmReferences edit Hibberd David J Norris Richard E 1984 Cytology and ultrastructure of Chlorarachnion reptans Chlorarchniophyta Divisio nova Chlorachniophyceae Classis nova Journal of Phycology 20 2 310 330 doi 10 1111 j 0022 3646 1984 00310 x S2CID 86059445 a b Hirakawa et al 2011 Morphological Diversity between Culture Strains of a Chlorarachniophyte Lotharella globosa PLOS ONE 6 8 e23193 Bibcode 2011PLoSO 623193H doi 10 1371 journal pone 0023193 PMC 3156133 PMID 21858028 a b Brodie Juliet Lewis Jane 26 November 2007 Unravelling the algae the past present and future of algal systematics CRC Press ISBN 9780849379901 Keeling PJ 2009 Chromalveolates and the evolution of plastids by secondary endosymbiosis J Eukaryot Microbiol 56 1 1 8 doi 10 1111 j 1550 7408 2008 00371 x PMID 19335769 S2CID 34259721 Nakayama Takuro Takahashi Kazuya Kamikawa Ryoma Iwataki Mitsunori Inagaki Yuji Tanifuji Goro 2020 Putative genome features of relic green alga derived nuclei in dinoflagellates and future perspectives as model organisms Communicative and Integrative Biology 13 1 84 88 doi 10 1080 19420889 2020 1776568 PMC 7518460 PMID 33014260 M D Guiry 2016 Chlorarachniophyceae Chlorarachnea AlgaeBase World wide electronic publication National University of Ireland Galway retrieved 25 October 2016 Cavalier Smith 2017 Kingdom Chromista and its eight phyla a new synthesis emphasising periplastid protein targeting cytoskeletal and periplastid evolution and ancient divergences Protoplasma 255 1 297 357 doi 10 1007 s00709 017 1147 3 PMC 5756292 PMID 28875267External links editAlgaeBase Chlorarachniophyta Systematic Biology Chlorarachniophyta Systematic Biology Cercozoa Archived 2015 04 02 at the Wayback Machine Tree of Life Chlorarachniophyta nbsp Wikispecies has information related to Chlorarachniophyta Retrieved from https en wikipedia org w index php title Chlorarachniophyte amp oldid 1178644964, wikipedia, wiki, book, books, library,
