Haptophyte

From Wikipedia, the free encyclopedia

Haptophytes
Coccolithus pelagicus.jpg
Coccolithophore ()
Scientific classification
Domain:
Eukaryota
(unranked):
Diaphoretickes
(unranked):
Hacrobia
(unranked):
Haptophyta

Hibberd 1976 sensu Ruggerio et al. 2015
Classes & Orders
Synonyms
  • Prymnesiophyta Green & Jordan, 1994
  • Prymnesiophyceae s.l. Casper, 1972, ex Hibberd, 1976
  • Haptophyceae s.l. Christensen, 1962 ex Silva, 1980
  • Haptophytina Cavalier-Smith 2015

The haptophytes, classified either as the Haptophyta, Haptophytina or Prymnesiophyta (named for Prymnesium), are a clade of algae.

The names Haptophyceae or Prymnesiophyceae are sometimes used instead.[1][2][3] This ending implies classification at the class rank rather than as a division. Although the phylogenetics of this group has become much better understood in recent years, there remains some dispute over which rank is most appropriate.

Characteristics[]

Cell scheme. 1-haptonema, 2-flagella, 3-mitochondrion, 4-Golgi apparatus, 5-nucleus, 6-scales, 7-chrysolaminarin vacuole, 8-plastid, 9-ribosomes, 10-stigma, 11-endoplasmic reticulum, 12-chloroplast endoplasmic reticulum, 13-pyrenoid, 14-thylakoids.

The chloroplasts are pigmented similarly to those of the heterokonts,[4] 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 similar red algal endosymbionts.

The cells typically have two slightly unequal flagella, both of which are smooth, and a unique organelle called a haptonema, which is superficially similar to a flagellum but differs in the arrangement of microtubules and in its use. The name comes from the Greek hapsis, touch, and nema, thread. The mitochondria have tubular cristae.

Significance[]

The best-known haptophytes are coccolithophores, which make up 673 of the 762 described haptophyte species,[5] and have an exoskeleton of calcareous plates called coccoliths. Coccolithophores are some of the most abundant marine phytoplankton, especially in the open ocean, and are extremely abundant as microfossils, forming chalk deposits. Other planktonic haptophytes of note include Chrysochromulina and Prymnesium, which periodically form toxic marine algal blooms, and Phaeocystis, blooms of which can produce unpleasant foam which often accumulates on beaches.[6]

Haptophytes are economically important, as species such as and Isochrysis sp. are widely used in the aquaculture industry to feed oyster and shrimp larvae. They contain a large amount of polyunsaturated fatty acids such as docosahexaenoic acid (DHA), stearidonic acid and alpha-linolenic acid.[7] Tisochrysis lutea contains betain lipids and phospholipids.[8]

Classification[]

Further information: Wikispecies:Haptophyta

The haptophytes were first placed in the class Chrysophyceae (golden algae), but ultrastructural data have provided evidence to classify them separately.[9] 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.[6]

Haptophytes was discussed to be closely related to cryptomonads.[10]

Haptophytes are closely related to the SAR clade.[11]

Subphylum Haptophytina Cavalier-Smith 2015 [Haptophyta Hibberd 1976 sensu Ruggerio et al. 2015][12]

  • Clade Kim et al. 2011
    • Class Rappephyceae Cavalier-Smith 2015
      • Order
        • Family
  • Clade (Margulis & Schwartz 1998) [Haptophyta Hibberd 1976 emend. Edvardsen & Eikrem 2000; Prymnesiophyta Green & Jordan, 1994; Prymnesiomonada; Prymnesiida Hibberd 1976; Haptophyceae Christensen 1962 ex Silva 1980; Haptomonadida; Patelliferea Cavalier-Smith 1993]
    • Class Pavlovophyceae Cavalier-Smith 1986 [Pavlovophycidae Cavalier-Smith 1986]
      • Order Pavlovales Green 1976
        • Family Pavlovaceae Green 1976
    • Class Prymnesiophyceae Christensen 1962 emend. Cavalier-Smith 1996 [Haptophyceae s.s.; Prymnesiophycidae Cavalier-Smith 1986; Coccolithophyceae Casper 1972 ex Rothmaler 1951]
      • Family † Kristan-Tollmann 1988 [Conusphaeraceae]
      • Family † Deflandre 1957
      • Family †Lapideacassaceae Black, 1971
      • Family † Deflandre 1963
      • Family † Deflandre 1959
      • Family † Forchheimer 1972 emend Varol, 1992
      • Family † Deflandre 1959
      • Family † Bown, 2005
      • Family Deflandre 1947
      • Family Norris 1965 emend Young & Bown 2014 [Triquetrorhabdulaceae Lipps 1969 - cf Young & Bown 2014]
      • Family Young et al., 2003
      • Family Jordan & Young 1990 emend Andruleit & Young 2010
      • Family Young et al., 2003 [Umbellosphaeroideae]
      • Order † Hay 1977
        • Family † Tan 1927
        • Family † Hay & Mohler 1967
        • Family † Deflandre 1952
        • Family † Hay & Mohler 1967
      • Order Medlin 2000
        • Family Lagerheim 1896
      • Order Papenfuss 1955 emend. Edvardsen and Eikrem 2000
        • Family Edvardsen, Eikrem & Medlin 2011
        • Family Prymnesiaceae Conrad 1926 ex Schmidt 1931
      • Subclass
        • Order Isochrysidales Pascher 1910 [Prinsiales Young & Bown 1997]
          • Family † Hay & Mohler 1967 emend. Young & Bown, 1997
          • Family Isochrysidaceae Parke 1949 [Chrysotilaceae; Marthasteraceae Hay 1977]
          • Family Noëlaerhabdaceae Jerkovic 1970 emend. Young & Bown, 1997 [Gephyrocapsaceae Black 1971]
        • Order † Rood, Hay & Barnard 1971 (loxolith; imbricating murolith)
          • Family † Rood, Hay & Barnard 1973 [Ahmuellerellaceae Reinhardt, 1965]
          • Family † Reinhardt 1965
          • Family † Hay 1977
        • Order Bown & Young 1997 (protolith; non-imbrication murolith)
          • Family Bown 1987
          • Family † Black 1968 emend. Black 1973
        • Order Young & Bown 1997 [Crepidolithales]
          • Family Black 1971
          • Family Lemmermann 1908
          • Family † Hay & Mohler 1967
        • Order Syracosphaerales Ostenfeld 1899 emend. Young et al., 2003 [Rhabdosphaerales Ostenfeld 1899]
          • Family Kamptner 1927
          • Family Syracosphaeraceae Lohmann, 1902 [Halopappiaceae Kamptner 1928] (caneolith & cyrtolith; murolith)
          • Family Rhabdosphaeraceae Haeckel, 1894 (planolith)
        • Order † Bown 1987 (imbricating placolith)
          • Family † Rood, Hay & Barnard 1971
        • Order † Bown & Hampton 1997
          • Family † Bukry 1969
          • Family † Bown & Hampton 1997
        • Order † Rood 1971 [Biscutales Aubry 2009; Prediscosphaerales Aubry 2009] (non-imbricating or radial placolith)
          • Family † Wind & Wise 1977 [Podorhabdaceae Noel 1965]
          • Family † Black, 1971
          • Family † Noel 1973
          • Family † Thierstein 1973
          • Family † Bown 1987
          • Family † Rood et al., 1971 [Deflandriaceae Black 1968]
          • Family † Bown & Rutledge 1997
        • Order Coccolithales Schwartz 1932 [Coccolithophorales]
          • Family Cavalier-Smith 1996 [Reticulosphaeridae]
          • Family Young & Bown 1997
          • Family Poche 1913 emend. Young & Bown, 1997 [Coccolithophoraceae]
          • Family Fresnel & Billard 1991
          • Family Senn 1900 [Ochrosphaeraceae Schussnig 1930]

References[]

  1. ^ "Haptophyta". NCBI taxonomy database. National Center for Biotechnology Information, U.S. National Library of Medicine.
  2. ^ 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. PMID 18830665. S2CID 18014503.
  3. ^ "ITIS Standard Report". Retrieved 19 July 2014.
  4. ^ 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. PMID 21652306.
  5. ^ "Haptophyta". Algaebase.
  6. ^ a b Cuvelier 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. PMC 2930470. PMID 20668244.
  7. ^ 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. S2CID 206766536.
  8. ^ 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.
  9. ^ Medlin LK (1997). Phylogenetic relationships of the 'golden algae' (haptophytes, heterokont chromophytes) and their plastids (PDF). Plant Systematics and Evolution. Vol. 11. pp. 187–219. doi:10.1007/978-3-7091-6542-3_11. ISBN 978-3-211-83035-2.
  10. ^ 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. PMID 19398025.
  11. ^ 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. PMC 3158185. PMID 21810989.
  12. ^ Guiry MD (2016), AlgaeBase, World-wide electronic publication, National University of Ireland, Galway, retrieved 25 October 2016

External links[]

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