Journal of Applied Phycology

, Volume 25, Issue 6, pp 1763–1776 | Cite as

On the description of Tisochrysis lutea gen. nov. sp. nov. and Isochrysis nuda sp. nov. in the Isochrysidales, and the transfer of Dicrateria to the Prymnesiales (Haptophyta)

  • El Mahdi Bendif
  • Ian Probert
  • Declan C. Schroeder
  • Colomban de Vargas


The Isochrysidaceae is a family of non-calcifying organisms within the haptophyte order Isochrysidales. Isochrysis galbana, a species widely used as a food source in aquaculture, is the best-known representative of this family that contains three genera but only six described species. We sequenced partial nuclear small subunit (SSU) and large subunit rDNA and mitochondrial cytochrome oxidase 1 genes of 34 isochrysidacean culture strains (including authentic strains when available) and compared molecular phylogenetic inferences with cytological and ultrastructural observations. The isochrysidaceaen culture strain Isochrysis affinis galbana (Tahiti isolate), widely used in aquaculture and commonly known as T-Iso, is clearly genetically distinct from Isochrysis galbana, despite seemingly being morphologically identical. A strain with a similar ultrastructure to that of Isochrysis galbana except for the lack of body scales had sequences that were more similar to but still distinct from those of Isochrysis galbana. Dicrateria inornata, a species that lacks body scales, is classified within the Isochrysidaceae, but the SSU rDNA sequence of the authentic strain of this species matches that of Imantonia rotunda within another haptophye order, the Prymnesiales. D. inornata and Imantonia rotunda have similar ultrastructure except for the respective absence/presence of scales. These results lead us to propose the erection of one new genus (Tisochrysis gen. nov.) and two new species (Tisochrysis lutea sp. nov. and Isochrysis nuda sp. nov.). D. inornata is reclassified within the Prymnesiales, and Imantonia rotunda is transferred to this genus (Dicrateria rotunda comb. nov.).


Dicrateria Imantonia Isochrysidaceae Isochrysis galbana Phylogeny Taxonomy Ultrastructure 



We thank Richard Pipe and Maria Jutson from the Plymouth Culture Collection and Benoit Véron and Bertrand Le Roy from the Algobank Culture Collection for providing Isochrysidales strains. From the Station Biologique de Roscoff, we thank Morgan Perennou and Gwen Tanguy from the GENOMER platform and Sophie Le Panse from the microscopy platform for technical assistance. We are also grateful to Bruno de Reviers for helpful discussions on taxonomic details and the three anonymous reviewers who helped in improving this study. This work was supported by a Ph.D. grant from the Region Bretagne (EMB) and by the following research programs: the EC FP7–“European Project on Ocean Acidification” (EPOCA, grant agreement 211384; EMB, DCS, CdV), the EU FP7 I3 program ASSEMBLE (grant 227799), the Interreg IV program MARINEXUS (IP) and the EU EraNet BiodivERsA program “Biodiversity of Marine euKaryotes” (BioMarKs; CdV).


  1. Anand PL (1936) Seven new Chrysophyceae from the south-east of England. Proceedings of the Tweny Third Indian Science Congress, Indore, pp 282–283Google Scholar
  2. Anand PL (1937) A taxonomic study of the algae of British chalk-cliffs. J Bot 7:289–297Google Scholar
  3. Bendif EM, Probert I, Hervé A, Billard C, Goux D, Lelong C, Cadoret JP, Véron B (2011) A taxonomic reassessment of the Pavlovophyceae (Haptophyta). Protist 162:738–761CrossRefGoogle Scholar
  4. Billard C, Gayral P (1972) Two new species of Isochrysis with remarks on the genus Ruttnera. Br Phycol J:289–297Google Scholar
  5. Billard C, Inouye I (2004) What is new in coccolithophore biology? In: Thierstein HR, Young JR (eds) Coccolithophores: From Molecular Processes to Global Impact. Springer, Berlin, pp 1–31Google Scholar
  6. Bougaran G, Le Déan L, Lukomska E, Kaas R, Baron R (2003) Transient initial phase in continuous culture of Isochrysis galbana affinis Tahiti. Aquat Living Resour 16:389–394CrossRefGoogle Scholar
  7. Brassell SC, Dumitrescu M (2004) Recognition of alkenones in a lower Aptian porcellanite from the west-central Pacific. Org Geochem 35:181–188CrossRefGoogle Scholar
  8. Brassell SC, Eglinton G, Marlowe IT, Plaufmann U, Sarnthein M (1986) Molecular stratigraphy: a new tool for climatic assessment. Nature 320:129–133CrossRefGoogle Scholar
  9. Brown MR, Garland CD, Jeffrey SW, Jameson ID, Leroi JM (1993) The gross and amino acid compositions of batch and semi-continuous cultures of Isochrysis sp. (clone T.ISO), Pavlova lutheri and Nannochloropsis oculata. J Appl Phycol 5:285–296CrossRefGoogle Scholar
  10. Chisti Y (2007) Biodiesel frome microalgae. Biotech Adv 25:294–306CrossRefGoogle Scholar
  11. Conte MH, Volkman JK, Eglington G (1994) Lipid biomarkers of the Haptophyta. In: Green JC, Leadbeater BSC (eds) The haptophyte algae. The Systematics Association special volume 51. Oxford University Press, Oxford, pp 265–85Google Scholar
  12. Coolen MJL, Muyzer G, Rijpstra WIC, Schouten S, Volkman JK, Damste JSS (2004) Combined DNA and lipid analyses of sediments reveal changes in Holocene haptophyte and diatom populations in an Antarctic lake. Earth Planet Sci Lett 223:225–239CrossRefGoogle Scholar
  13. de Vargas C, Aubry MP, Probert I, Young J (2007) Origin and evolution of coccolithophores: from coastal hunters to oceanic farmers. In: Falkowski PG, Knoll A (eds) Evolution of primary producers in the sea. Academic Press, NY, pp 251–285CrossRefGoogle Scholar
  14. Edvardsen B, Eikrem W, Green JC, Andersen RA, Moon-van der Staay SY, Medlin LK (2000) Phylogenetic reconstructions of the Haptophyta inferred from SSU ribosomal DNA sequences and available morphological data. Phycologia 39:19–35CrossRefGoogle Scholar
  15. Ewart JW, Pruder GD (1981) Comparative growth of Isochrysis galbana Parke and Isochrysis aff. galbana, clone T-ISO at four temperatures and three light intensities. J World Maricult Soc 12:333–339CrossRefGoogle Scholar
  16. Farmer C (1993) Steroidal-diols and long-chain ketones as biomarkers of Prymnesiophyte algae. Honours Thesis, University of Tasmania, Hobart, AustraliaGoogle Scholar
  17. Green JC, Parke M (1975) New observations upon members of the genus Chrysotila Anand, with remarks upon their relationships within the Haptophyceae. J Mar Biol Assoc UK 55:109–121CrossRefGoogle Scholar
  18. Green JC, Pienaar RN (1977) The taxonomy of the order Isochrysidales (Prymnesiophyceae) with special reference to the genera Isochrysis Parke, Dicrateria Parke and Imantonia Reynolds. J Mar Biol Assoc UK 57:7–17CrossRefGoogle Scholar
  19. Green JC, Course PA (1983) Extracellular calcification in Chrysotila lamellosa (Prymnesiophyceae). Br Phycol J 18:367–382CrossRefGoogle Scholar
  20. Green JC, Course PA, Tarran GA (1996) The life cycle of Emiliania huxleyi: a brief review and a study of relative ploidy levels analysed by flow cytometry. J Mar Syst 9:33–44CrossRefGoogle Scholar
  21. Hall TA (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symp 41:95–98Google Scholar
  22. Hayashi-Ishimaru Y, Ehara M, Inagaki Y, Ohama T (1997) A deviant genetic code in Prymnesiophytes (yellow-algae): UGA codon for tryptophan. Curr Genet 32:296–299PubMedCrossRefGoogle Scholar
  23. Houdan A, Billard C, Marie D, Not F, Saez A, Young G, Probert I (2004) Holococcolithophores–heterococcolithophores (Haptophyta) life cycles: flow cytometry analysis of relative ploidy levels. Syst Biodivers 1:453–465CrossRefGoogle Scholar
  24. Inouye I (1997) Systematics of haptophyte algae in Asia-Pacific waters. Algae 12:247–261Google Scholar
  25. Jeffrey SW, Wright SW (1994) Photosynthetic pigments in the Haptophyta. In: Green JC, Leadbeater BSC (eds) The haptophyte algae. The Systematics Association special volume 51. Oxford University Press, Oxford, pp 113–132Google Scholar
  26. Jeffrey SW, Brown MR, Volkman JK (1994) Haptophytes as feedstocks in mariculture. In: Green JC, Leadbeater BSC (eds) The haptophyte algae. The Systematics Association special volume 51. Oxford University Press, Oxford, pp 265–285Google Scholar
  27. Jerkovic L (1970) Noelaerhabdus nov. gen. Type d’une nouvelle famille de coccolithophoridés fossiles: Noëlaerhabdaceae du Miocène supérieur de Yougoslavie. C R Acad Sci Paris 270:468–470Google Scholar
  28. Jobb G, von Haeseler A, Strimmer K (2004) TREEFINDER: a powerful graphical analysis environment for molecular phylogenetics. BMC Evol Biol 28:4–18Google Scholar
  29. Jordan RW, Cros L, Young JR (2005) A revised classification scheme for living haptophytes. Micropaleontology 50(suppl 1):55–79Google Scholar
  30. Katoh K, Kuma K, Toh H, Miyata T (2007) MAFFT version 5: improvement in accuracy of multiple sequence alignment. Nucleic Acids Res 33:511–518CrossRefGoogle Scholar
  31. Keller MD, Selvin RC, Claus W, Guillard RRL (1987) Media for the culture of oceanic ultraphytoplankton. J Phycol 23:633–638CrossRefGoogle Scholar
  32. Liu CP, Lin LP (2001) Ultrastructural study and lipid formation of Isochrysis sp. CCMP1324. Bot Bull Acad Sin 42:207–214Google Scholar
  33. Liu H, Aris-Brosou S, Probert I, de Vargas C (2010) A timeline of the environmental genetics of the haptophytes. Mol Biol Evol 27:171–176Google Scholar
  34. Manton I (1966) Further observations on the fine structure of Chrysochromulina chiton, with special reference to the pyrenoid. J Cell Sci 1:187–192Google Scholar
  35. Manton I (1967) Further observations on the fine structure of Chrysochromulina chiton with special reference to the haptonema, “peculiar” Golgi structure and scale production. J Cell Sci 2:265–272PubMedGoogle Scholar
  36. Marlowe IT, Green JC, Neal AC, Brassell SC, Eglington G, Course PA (1984) Long chain (n-C37-C39) alkenones in the Prymnesiophyceae. Distribution of alkenones and other lipids and their taxonomic significance. Br Phycol J 19:203–216CrossRefGoogle Scholar
  37. Medlin LK, Sàez AG, Young JR (2008) A molecular clock for coccolithophores and implications for selectivity of phytoplankton extinctions across the K T boundary. Mar Micropaleontol 67:69–86CrossRefGoogle Scholar
  38. Müller PJ, Kirst G, Ruhland G, von Storch I, Rosell-Mele A (1998) Calibration of the alkenone paleotemperature index UK'37 based on core-tops from the eastern South Atlantic and the global ocean (60°N–60°S). Geochim Cosmochim Acta 62:1757–1772CrossRefGoogle Scholar
  39. O'Shea SK, Holland F, Bilodeau A (2010) Modeling the effects of salinity and pH on the cadmium bioabsorptive properties of the microalgae Isochrysis galbana (T-Iso) in coastal waters. J Coast Res 26:56–66Google Scholar
  40. Parke M (1949) Studies on marine flagellates. J Mar Biol Assoc UK 28:255–286CrossRefGoogle Scholar
  41. Pascher A (1910) Chrysomonaden aus dem Hirschberger Grossteiche. Int Rev Ges Hydrobiol Hydrogr 1:1–66Google Scholar
  42. Patterson GW, Tsitsa-Tsardis E, Wikfors GH, Gladu PK, Chitwood DJ, Harrison D (1994) Sterols and alkenones of Isochrysis. Phytochemistry 35:1233–1236CrossRefGoogle Scholar
  43. Pennick NC (1977) Studies on the external morphology of Pyramimonas. 4. Pyramimonas virginica sp. Arch Protistenkd 119:239–246Google Scholar
  44. Quast C, Pruesse E, Yilmaz P, Gerken J, Schweer T, Yarza P, Peplies J, Glöckner FO (2013) The SILVA ribosomal RNA gene database project: improved data processing and web-based tools. Nucl Acids Res 41:590–596CrossRefGoogle Scholar
  45. Reynolds ES (1963) The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol 17:208–212PubMedCentralPubMedCrossRefGoogle Scholar
  46. Reynolds N (1974) Imantonia rotunda gen. et sp. nov., a new member of the Haptophyceae. Br Phycol J 9:429–434CrossRefGoogle Scholar
  47. Ronquist F, Huelsenbeck JP (2003) MRBAYES 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 19:1572–1574PubMedCrossRefGoogle Scholar
  48. Sáez AG, Probert I, Young J, Edvardsen B, Eikrem W, Medlin LK (2004) A review of the phylogeny of the Haptophyta. In: Thierstein HR, Young JR (eds) Coccolithophores—from molecular processes to global impact. Springer, Berlin, pp 251–269Google Scholar
  49. Sogin ML (1990) Amplification of ribosomal RNA genes for molecular evolution studies. In: Innes MA, Gelfand DH, Sninsky JJ, White TJ (eds) PCR protocols. Academic, San Diego, pp 307–320Google Scholar
  50. Van der Wal P, Leunissen-Buvelt JJM, Verkleijs AJ (1985) Ultrastructure of the membranous layers enveloping the cell of the coccolithophorid Emiliania huxleyi. J Ultrastruct Res 91:24–29CrossRefGoogle Scholar
  51. Zapata M, Jeffrey SW, Wright SW, Rodriguez F, Garrido JL, Clementson L (2004) Photosynthetic pigments in 37 species (65 strains) of Haptophyta: implications for oceanography and chemotaxonomy. Mar Ecol Prog Ser 270:83–102CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • El Mahdi Bendif
    • 1
  • Ian Probert
    • 2
  • Declan C. Schroeder
    • 3
  • Colomban de Vargas
    • 1
  1. 1.Groupe Plancton, Station Biologique de RoscoffCNRS-UPMC (Université Paris-06), UMR 7144Roscoff CedexFrance
  2. 2.Station Biologique de RoscoffCNRS-UPMC (Université Paris-06), FR2424Roscoff CedexFrance
  3. 3.Marine Biological Association of the United KingdomPlymouthUK

Personalised recommendations