World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0001565377
Reproduction Date:

Title: Haptophyta  
Author: World Heritage Encyclopedia
Language: English
Subject: Algae, Chloroplast, Flagellate, Coccolithophore, Kingdom (biology), Cryptomonad, Thomas Cavalier-Smith, Chromalveolata, Prymnesium parvum, Photosynthetic picoplankton
Publisher: World Heritage Encyclopedia


Coccolithophore (Coccolithus pelagicus)
Scientific classification
Domain: Eukaryota
Kingdom: Chromalveolata
Division: Haptophyta
Hibberd 1976
Classes & Orders

Class Pavlovophyceae


Class Prymnesiophyceae


The haptophytes, classified either as the Prymnesiophyta or Haptophyta, are a division of algae.

The term "Haptophyceae" is sometimes used.[1][2] This ending implies classification at a lower level. However, although the phylogenetics of this group has become much more understood in recent years, there remains some dispute over which taxon level is most appropriate.


The chloroplasts are pigmented similarly to those of the heterokonts,[3] 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 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.

Economic importance

Haptophytes are economically important as Pavlova lutheri and Isochrysis sp. are widely used in the aquaculture industries.

Examples and classification

The best-known haptophytes are coccolithophores, which 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. 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. 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[4]

Haptophytes are closely related to cryptomonads.[5]


External links

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.