Phycology is the study of algae. However, just what algae are is difficult to define, because they belong to many different and unrelated taxonomic groups and include both prokaryotic and eukaryotic representatives. Broadly speaking, the algae comprise all, mainly aquatic, plants and plant‐like chlorophyll a‐containing organisms that can use light energy to fix carbon from atmospheric carbon dioxide (CO2) and evolve oxygen, but which are not specialised land plants like mosses, ferns, coniferous trees and flowering plants. This is a negative definition, but it serves its purpose. Besides being a principal source of oxygen, algae are important primary producers in many, mainly aquatic, habitats and are the source of a number of important commercial products and molecules.

Key Concepts:

  • The algae are a very diverse group of plants and plant‐like organisms but which are not specialised land plants like mosses, ferns, coniferous trees and flowering plants.

  • The algae include both prokaryotic and eukaryotic organisms.

  • Algae are key providers of oxygen on earth and are the basis of aquatic food webs.

  • Algae have a wide range of commercial applications.

  • Endosymbiosis has played an important part in the evolution of the algae.

Keywords: algae; seaweeds; phytoplankton; prokaryotes; eukaryotes; symbiosis; taxonomy

Figure 1.

A red cell of Dunaliella salina containing a large amount of carotenoid.

Figure 2.

The Dunaliella salina production plant at Hutt Lagoon, Western Australia showing the red coloured ponds. The plant is over 700 ha in area.

Figure 3.

The red alga Martensia, which has a very complex thallus morphology. (Reproduced with permission from John Huisman.)

Figure 4.

Amphiroa anceps, a calcareous red alga. (Reproduced with permission from John Huisman.)

Figure 5.

Dictyota ciliolata, a brown algae with a flattened thallus. (Reproduced with permission from John Huisman.)

Figure 6.

The coccolithophorid alga Discophaera tubifera with its unusually trumpet‐shaped coccoliths. The cell can be seen at the base of the coccoliths (scale=5 μm).

Figure 7.

The green alga Caulera racemosa. (Reproduced with permission from John Huisman.)



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Further Reading

Andersen RA (ed.) (2005) Algal Culturing Techniques. Amsterdam: Elsevier.

Bold HC and Wynne MJ (1978) Introduction to the Algae. New York: Prentice‐Hall.

Borowitzka MA and Borowitzka LJ (eds) (1988) Micro‐algal Biotechnology. Cambridge: Cambridge University Press.

Chan CX and Bhattacharya D (2010) The origin of plastids. Nature Education 3(9): 84‐origin‐of‐plastids‐14125758.

Draisma SGA, Prud'homme van Reine WF, Stam WT and Olsen JL (2001) A reassessment of phylogenetic relationships within the Phaeophyceae based on Rubisco large subunit and ribosomal DNA sequences. Journal of Phycology 37: 586–603.

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Huisman JM and Saunders GW (2007) Phylogeny and classification of the algae. In: McCarthy PM and Orchard AE (eds) Algae of Australia. Introduction. pp. 66–103. Canberra: ABRS.

Lee RE (2008) Phycology, 4th edn. Cambridge: Cambridge University Press.

Richmond A (ed.) (2004) Handbook of Microalgal Culture. Oxford: Blackwell Publishing.

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Borowitzka, Michael A(Apr 2012) Phycology. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0000334.pub3]