Haptophyte
| Haptophytes | |
|---|---|
| |
| Coccolithophore(Coccolithus pelagicus) | |
Scientific classification
| |
| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Phylum: | Haptista |
| Subphylum: | Haptophytina Hibberd, 1976stat. nov.Cavalier-Smith, 2015[1] |
| Classes & Orders | |
| Synonyms | |
| |
Thehaptophytes,classified either as theHaptophyta,HaptophytinaorPrymnesiophyta(named forPrymnesium), are acladeofalgae.
The namesHaptophyceaeorPrymnesiophyceaeare sometimes used instead.[2][3][4]This ending implies classification at theclassrankrather than as a division. Although thephylogeneticsof this group has become much better understood in recent years, there remains some dispute over which rank is most appropriate.
Characteristics[edit]
Thechloroplastsare pigmented similarly to those of theheterokonts,[5]but the structure of the rest of the cell is different, so it may be that they are a separate line whose chloroplasts are derived from similarred algalendosymbionts.
The cells typically have two slightly unequalflagella,both of which are smooth, and a unique organelle called ahaptonema,which is superficially similar to a flagellum but differs in the arrangement ofmicrotubulesand in its use. The name comes from theGreekhapsis,touch, andnema,round thread. Themitochondriahave tubularcristae.
Significance[edit]
The best-known haptophytes arecoccolithophores,which make up 673 of the 762 described haptophyte species,[6]and have an exoskeleton of calcareous plates calledcoccoliths.Coccolithophores are some of the most abundant marinephytoplankton,especially in the open ocean, and are extremely abundant as microfossils, formingchalkdeposits. Other planktonic haptophytes of note includeChrysochromulinaandPrymnesium,which periodically form toxic marinealgal blooms,andPhaeocystis,blooms of which can produce unpleasant foam which often accumulates on beaches.[7]
Haptophytes are economically important, as species such asPavlova lutheriandIsochrysissp.are widely used in theaquacultureindustry to feedoysterandshrimplarvae. They contain a large amount ofpolyunsaturated fatty acidssuch asdocosahexaenoic acid(DHA),stearidonic acidandAlpha -linolenic acid.[8]Tisochrysis luteacontains betain lipids andphospholipids.[9]
Classification[edit]
The haptophytes were first placed in the classChrysophyceae(golden algae), but ultrastructural data have provided evidence to classify them separately.[10]Both molecular and morphological evidence supports their division into five orders; coccolithophores make up the Isochrysidales and Coccolithales. Very small (2-3μm) uncultured pico-prymnesiophytes are ecologically important.[7]
Haptophytes was discussed to be closely related tocryptomonads.[11]
Haptophytes are closely related to theSARclade.[12]
Subphylum HaptophytinaCavalier-Smith 2015[HaptophytaHibberd 1976 sensu Ruggerio et al. 2015][13]
- CladeRappemonadaKim et al. 2011
- ClassRappephyceaeCavalier-Smith 2015
- OrderRappemonadales
- FamilyRappemonadaceae
- OrderRappemonadales
- ClassRappephyceaeCavalier-Smith 2015
- CladeHaptomonada(Margulis & Schwartz 1998)[Haptophyta Hibberd 1976 emend. Edvardsen & Eikrem 2000; PrymnesiophytaGreen & Jordan, 1994;Prymnesiomonada; Prymnesiida Hibberd 1976; Haptophyceae Christensen 1962 ex Silva 1980; Haptomonadida; Patelliferea Cavalier-Smith 1993]
- ClassPavlovophyceaeCavalier-Smith 1986[PavlovophycidaeCavalier-Smith 1986]
- OrderPavlovalesGreen 1976
- FamilyPavlovaceaeGreen 1976
- OrderPavlovalesGreen 1976
- ClassPrymnesiophyceaeChristensen 1962 emend. Cavalier-Smith 1996[Haptophyceae s.s.; PrymnesiophycidaeCavalier-Smith 1986;CoccolithophyceaeCasper 1972 ex Rothmaler 1951]
- Family †EoconusphaeraceaeKristan-Tollmann 1988[Conusphaeraceae]
- Family †GoniolithaceaeDeflandre 1957
- Family †LapideacassaceaeBlack, 1971
- Family †MicrorhabdulaceaeDeflandre 1963
- Family †NannoconaceaeDeflandre 1959
- Family †PolycyclolithaceaeForchheimer 1972 emend Varol, 1992
- Family †LithostromationaceaeDeflandre 1959
- Family †RhomboasteraceaeBown, 2005
- FamilyBraarudosphaeraceaeDeflandre 1947
- FamilyCeratolithaceaeNorris 1965 emend Young & Bown 2014[TriquetrorhabdulaceaeLipps 1969 - cf Young & Bown 2014]
- FamilyAlisphaeraceaeYoung et al., 2003
- FamilyPapposphaeraceaeJordan & Young 1990 emend Andruleit & Young 2010
- FamilyUmbellosphaeraceaeYoung et al., 2003[Umbellosphaeroideae]
- Order †DiscoasteralesHay 1977
- Family †DiscoasteraceaeTan 1927
- Family †HeliolithaceaeHay & Mohler 1967
- Family †SphenolithaceaeDeflandre 1952
- Family †FasciculithaceaeHay & Mohler 1967
- OrderPhaeocystalesMedlin 2000
- FamilyPhaeocystaceaeLagerheim 1896
- OrderPrymnesialesPapenfuss 1955 emend. Edvardsen and Eikrem 2000
- FamilyChrysochromulinaceaeEdvardsen, Eikrem & Medlin 2011
- FamilyPrymnesiaceaeConrad 1926 ex Schmidt 1931
- SubclassCalcihaptophycidae
- OrderIsochrysidalesPascher 1910[PrinsialesYoung & Bown 1997]
- Family †PrinsiaceaeHay & Mohler 1967 emend. Young & Bown, 1997
- FamilyIsochrysidaceaeParke 1949[Chrysotilaceae; MarthasteraceaeHay 1977]
- FamilyNoëlaerhabdaceaeJerkovic 1970 emend. Young & Bown, 1997[GephyrocapsaceaeBlack 1971]
- Order †EiffellithalesRood, Hay & Barnard 1971(loxolith; imbricating murolith)
- Family †ChiastozygaceaeRood, Hay & Barnard 1973[AhmuellerellaceaeReinhardt, 1965]
- Family †EiffellithaceaeReinhardt 1965
- Family †RhagodiscaceaeHay 1977
- OrderStephanolithialesBown & Young 1997(protolith; non-imbrication murolith)
- FamilyParhabdolithaceaeBown 1987
- Family †StephanolithiaceaeBlack 1968 emend. Black 1973
- OrderZygodiscalesYoung & Bown 1997[Crepidolithales]
- FamilyHelicosphaeraceaeBlack 1971
- FamilyPontosphaeraceaeLemmermann 1908
- Family †ZygodiscaceaeHay & Mohler 1967
- OrderSyracosphaeralesOstenfeld 1899 emend. Young et al., 2003[RhabdosphaeralesOstenfeld 1899]
- FamilyCalciosoleniaceaeKamptner 1927
- FamilySyracosphaeraceaeLohmann, 1902[HalopappiaceaeKamptner 1928] (caneolith & cyrtolith; murolith)
- FamilyRhabdosphaeraceaeHaeckel, 1894(planolith)
- Order †WatznauerialesBown 1987(imbricating placolith)
- Family †WatznaueriaceaeRood, Hay & Barnard 1971
- Order †ArkhangelskialesBown & Hampton 1997
- Family †ArkhangelskiellaceaeBukry 1969
- Family †KamptneriaceaeBown & Hampton 1997
- Order †PodorhabdalesRood 1971[BiscutalesAubry 2009;PrediscosphaeralesAubry 2009] (non-imbricating or radial placolith)
- Family †AxopodorhabdaceaeWind & Wise 1977[PodorhabdaceaeNoel 1965]
- Family †BiscutaceaeBlack, 1971
- Family †CalyculaceaeNoel 1973
- Family †CretarhabdaceaeThierstein 1973
- Family †MazaganellaceaeBown 1987
- Family †PrediscosphaeraceaeRood et al., 1971[DeflandriaceaeBlack 1968]
- Family †TubodiscaceaeBown & Rutledge 1997
- OrderCoccolithalesSchwartz 1932[Coccolithophorales]
- FamilyReticulosphaeraceaeCavalier-Smith 1996[Reticulosphaeridae]
- FamilyCalcidiscaceaeYoung & Bown 1997
- FamilyCoccolithaceaePoche 1913 emend. Young & Bown, 1997[Coccolithophoraceae]
- FamilyPleurochrysidaceaeFresnel & Billard 1991
- FamilyHymenomonadaceaeSenn 1900[OchrosphaeraceaeSchussnig 1930]
- OrderIsochrysidalesPascher 1910[PrinsialesYoung & Bown 1997]
- ClassPavlovophyceaeCavalier-Smith 1986[PavlovophycidaeCavalier-Smith 1986]
References[edit]
- ^Cavalier-Smith, Thomas (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.PMID28875267.S2CID19939172.
- ^"Haptophyta".NCBI taxonomy database.National Center for Biotechnology Information, U.S. National Library of Medicine.
- ^Satoh M, Iwamoto K, Suzuki I, Shiraiwa Y (2009)."Cold stress stimulates intracellular calcification by the coccolithophore, Emiliania huxleyi (Haptophyceae) under phosphate-deficient conditions".Marine Biotechnology.11(3): 327–33.doi:10.1007/s10126-008-9147-0.hdl:2241/104412.PMID18830665.S2CID18014503.
- ^"ITIS Standard Report".Retrieved19 July2014.
- ^Andersen RA (October 2004). "Biology and systematics of heterokont and haptophyte algae".American Journal of Botany.91(10): 1508–22.doi:10.3732/ajb.91.10.1508.PMID21652306.
- ^"Haptophyta".Algaebase.Archived fromthe originalon 2021-02-18.Retrieved2019-10-27.
- ^abCuvelier ML, Allen AE, Monier A, McCrow JP, Messié M, Tringe SG, et al. (August 2010)."Targeted metagenomics and ecology of globally important uncultured eukaryotic phytoplankton".Proceedings of the National Academy of Sciences of the United States of America.107(33): 14679–84.Bibcode:2010PNAS..10714679C.doi:10.1073/pnas.1001665107.PMC2930470.PMID20668244.
- ^Renaud SM, Zhou HC, Parry DL, Thinh LV, Woo KC (1995). "Effect of temperature on the growth, total lipid content and fatty acid composition of recently isolated tropical microalgae Isochrysis sp., Nitzschia closterium, Nitzschia paleacea, and commercial species Isochrysis sp. (clone T.ISO)".Journal of Applied Phycology.7(6): 595–602.doi:10.1007/BF00003948.S2CID206766536.
- ^Kato M, Sakai M, Adachi K, Ikemoto H, Sano H (1996). "Distribution of betaine lipids in marine algae".Phytochemistry.42(5): 1341–5.doi:10.1016/0031-9422(96)00115-X.
- ^Medlin LK (1997). "Phylogenetic relationships of the 'golden algae' (Haptophytes, heterokont chromophytes) and their plastids".Origins of Algae and their Plastids(PDF).Plant Systematics and Evolution. Vol. 11. pp. 187–219.doi:10.1007/978-3-7091-6542-3_11.ISBN978-3-211-83035-2.Archived(PDF)from the original on 2012-03-17.
- ^Reeb VC, Peglar MT, Yoon HS, Bai JR, Wu M, Shiu P, et al. (October 2009). "Interrelationships of chromalveolates within a broadly sampled tree of photosynthetic protists".Molecular Phylogenetics and Evolution.53(1): 202–11.doi:10.1016/j.ympev.2009.04.012.PMID19398025.
- ^Parfrey LW, Lahr DJ, Knoll AH, Katz LA (August 2011)."Estimating the timing of early eukaryotic diversification with multigene molecular clocks".Proceedings of the National Academy of Sciences of the United States of America.108(33): 13624–9.Bibcode:2011PNAS..10813624P.doi:10.1073/pnas.1110633108.PMC3158185.PMID21810989.
- ^Guiry MD (2016),AlgaeBase,World-wide electronic publication, National University of Ireland, Galway,retrieved25 October2016
External links[edit]
