Haptophyta

Colony of Phaeocystis, copyright Peter Countway.

Belongs within: Hacrobia.

The Haptophyta are a group of aquatic flagellates, many of which are photosynthetic. Most members of this group have a covering of scales that may or may not be mineralised.

Characters (from Adl et al. 2012): Autotrophic, mixotrophic or heterotrophic cells; some in colonies or filaments; motile cells often possessing a filiform appendage (haptonema) situated between cilia; characteristic cell covering of unmineralised and/or mineralised scales; motile cells with two cilia generally without appendages, inserted apically or sub-apically in papilla or groove, or emerging from papilla; 1–4 chloroplasts with thylakoids in groups of three; chloroplasts with immersed or bulging pyrenoid; nucleus usually posterior; outer membrane of nuclear envelope continuous with outer chloroplast membrane; major pigments chlorophylls a, c₁, and c₂ with c₃ in prymnesiophyceans, β-carotene, diadinoxanthin, and diatoxanthin; chrysolaminarin often the main storage product; eyespots recorded in some Pavlovophyceae; life cycles include either single phases or alternating stages; in those with alternating stages, palmelloid (colonial) or filamentous stages alternate with motile stages; sexual reproduction may be common in prymnesiophyceans; some species ichthyotoxic.

Haptophyta [Haptophytina]
    |  i. s.: Calcidiscus leptoporus QT03
    |--Rappephyceae C-SCL15
    `--+--Pavlovophyceae [Pavlovophycidae] C-SCL15
       |    |--Diacronema C-SC06
       |    |    |--D. lutheri C-SCL15
       |    |    `--D. vlkianum C-SC06
       |    |--Pavlova C-SC06 [Pavlovaceae, Pavlovales]
       |    |    |--P. gyrans MO08
       |    |    |--P. lutheri MO08
       |    |    `--P. salina C-SA96
       |    `--Exanthemachrysis AS12
       `--Coccolithophyceae (see below for synonymy) C-SCL15
            |  i. s.: Umbilicosphaera P98
            |           |--U. hulburtiana QT03
            |           `--U. sibogae P98
            |         Scyphosphaera P98
            |           |--S. apstenii P98
            |           `--S. recurvata P98
            |         Pontosphaera P98
            |           |--P. japonica P98
            |           `--P. syracusana P98
            |         Ahmuellerella octoradiata P98
            |         Arkhangelskiella cymbiformis P98
            |         Anoplosolenia brasiliensis P98
            |         Rhabdosphaera claviger P98
            |         Speetonia Black 1971 FT93
            |         Rhabdothorax Kamptner 1958 FT93
            |         Syracosphaera Lohmann 1902 FT93
            |         Ceratolithus P79 [Ceratolithaceae P98]
            |           `--C. tricorniculatus P79
            |         Braarudosphaera [Braarudosphaeraceae] P98
            |           `--B. bigelowii P98
            |         Discoaster [Discoasteraceae] P98
            |           |--D. asymmetricus P79
            |           |--D. binodosus P79
            |           |--D. brouweri Tan 1927 VC88
            |           |--D. calcaris P79
            |           |--D. druggi P79
            |           |--D. exilis P79
            |           |--D. gemmeus P79
            |           |--D. hamatus P79
            |           |--D. kugleri P79
            |           |--D. lodoensis P79
            |           |--D. multiradiatus P79
            |           |--D. pentaradiatus P79
            |           |--D. quinqueramus P98
            |           |--D. saipanensis P79
            |           |--D. sublodoensis P79
            |           |--D. surculus P79
            |           `--D. tani P79
            |                |--D. t. tani P79
            |                `--D. t. nodifer P79
            |         Dicrateria [Dicrateriaceae, Dicrateriales] C-SA96
            |--+--Imantonia rotunda C-SC06
            |  `--Prymnesiales AS12
            |       |--Chrysochromulina C-SC06
            |       |    |--C. campanulifera OC09
            |       |    `--C. kappa C-SC06
            |       `--Prymnesium [Prymnesiaceae] C-SA96
            |            |--P. parvum MO08
            |            `--P. patelliferum C-SA96
            `--+--Coccolithales [Coccolithophorales] AS12
               |    |--Coccolithus C-SC06
               |    |    |--C. braarudii C-SCL15
               |    |    `--C. pelagicus C-SC06
               |    |--Balaniger AS12
               |    |--Calciosolenia [Calciosoleniaceae] AS12
               |    |--Hymenomonas AS12
               |    |--Pleurochrysis carterae AS12, MO08
               |    |--Reticulosphaera [Flavoretea, Flavoretophycidae, Reticulosphaeraceae, Reticulosphaerales] C-SA96
               |    |    |--R. japonensis C-SA96
               |    |    `--R. socialis C-SA96
               |    `--Wigwamma AS12
               `--+--Isochrysidales C-SA96
                  |    |--Emiliania huxleyi (Lohmann) Hay & Mohler 1967 C-SA96, AS12
                  |    |--Isochrysis [Isochrysidaceae] MO08
                  |    |    |--I. galbana Parke 1938 C03
                  |    |    `--I. zhangjiangensis OC09
                  |    `--Gephyrocapsa AS12
                  `--Phaeocystis Lagerheim 1893 C-SA96, AS12 [Phaeocystaceae]
                       |--P. antarctica C-SA96
                       |--P. globosa C-SA96
                       `--P. pouchetii C-SA96

Coccolithophyceae [Haptomonadida, Haptophyceae, Patelliferea, Prymnesiomonadida, Prymnesiophyceae, Prymnesiophycidae] C-SCL15

*Type species of generic name indicated

REFERENCES

[AS12] Adl, S. M., A. G. B. Simpson, C. E. Lane, J. Lukeš, D. Bass, S. S. Bowser, M. W. Brown, F. Burki, M. Dunthorn, V. Hampl, A. Heiss, M. Hoppenrath, E. Lara, E. Le Gall, D. H. Lynn, H. McManus, E. A. D. Mitchell, S. E. Mozley-Stanridge, L. W. Parfrey, J. Pawlowski, S. Rueckert, L. Shadwick, C. L. Schoch, A. Smirnov & F. W. Spiegel. 2012. The revised classification of eukaryotes. Journal of Eukaryotic Microbiology 59 (5): 429–493.

[C-SA96] Cavalier-Smith, T., M. T. E. P. Allsopp, M. M. Haueber, G. Goethe, E. E. Chao, J. A. Couch & U.-G. Maier. 1996. Chromobiote phylogeny: the enigmatic alga Reticulosphaera japonensis is an aberrant haptophyte, not a heterokont. European Journal of Phycology 31: 255–263.

[C-SC06] Cavalier-Smith, T., & E. E.-Y. Chao. 2006. Phylogeny and megasystematics of phagotrophic heterokonts (kingdom Chromista). Journal of Molecular Evolution 62: 388–420.

[C-SCL15] Cavalier-Smith, T., E. E. Chao & R. Lewis. 2015. Multiple origins of Heliozoa from flagellate ancestors: new cryptist subphylum Corbihelia, superclass Corbistoma, and monophyly of Haptista, Cryptista, Hacrobia and Chromista. Molecular Phylogenetics and Evolution 93: 331–362.

[C03] Chan, B. K. K. 2003. Studies on Tetraclita squamosa and Tetraclita japonica (Cirripedia: Thoracica) II: larval morphology and development. Journal of Crustacean Biology 23 (3): 522–547.

[FT93] Fensome, R. A., F. J. R. Taylor, G. Norris, W. A. S. Sarjeant, D. I. Wharton & G. L. Williams. 1993. A classification of living and fossil dinoflagellates. Micropaleontology Special Publication 7: i–viii, 1–351.

[MO08] Moore, R. B., M. Oborník, J. Janouškovec, T. Chrudimský, M. Vancová, D. H. Green, S. W. Wright, N. W. Davies, C. J. S. Bolch, K. Heimann, J. Šlapeta, O. Hoegh-Guldberg, J. M. Logsdon, Jr. & D. A. Carter. 2008. A photosynthetic alveolate closely related to apicomplexan parasites. Nature 451: 959–963.

[OC09] Okamoto, N., C. Chantangsi, A. Horák, B. S. Leander & P. J. Keeling. 2009. Molecular phylogeny and description of the novel katablepharid Roombia truncata gen. et sp. nov., and establishment of the Hacrobia taxon nov. PLoS One 4 (9): e7080.

[P79] Papp, A. 1979. Tertiary. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A488–A504. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[P98] Prothero, D. R. 1998. Bringing Fossils to Life: An introduction to paleobiology. WCB McGraw-Hill: Boston.

[QT03] Quinn, P., H. R. Thierstein, L. Brand & A. Winter. 2003. Experimental evidence for the species character of Calcidiscus leptoporus morphotypes. Journal of Paleontology 77 (5): 825–830.

[VC88] Vermeij, G. J. & T. M. Collins. 1988. Nerita fortidentata, a new gastropod from the Neogene of Panamá, with comments on the fossil record of Nerita in tropical America. Nautilus 102 (3): 102–105.