( Cystoseira compressa )

/ / Marine Flora


Cystoseira compressa has a discoid base with several spined axes; the axes have denticulate margins (1; 2). It is irregularly branched with compressed primary ramifications, and compact crawling receptacles; the axes have a height of 10-100mm, and a thickness of 2-5mm (1). This alga lacks any leaves, tophules and gas vacuoles (1); C. compressa has an olive-brown colouration.

There are approximately 58 species within the genus Cystoseira (3); none of the species are listed under the IUCN Redlist (4); however, C. amentacea, C. mediterranea, C. sedoides, C. spinose and C. zosteroides are all listed under Appendix I of the BERN Convention (5).


The species will often be covered in smaller algae; also tolerant of moderate waves (1).


C. compressa is located on hard substrates in the Medio-littoral zone down to 20m; however, it is most abundant in the upper-littoral zone within 1-3m (1).

Life Cycle

C. compressa is perennial; fertility is from March until June. After this, the upper branches break away (1).


C. compressa is distributed across western and eastern Mediterranean; including Greece, Milos and the Orei Channel (1).


C. compressa uses photosynthesis, as well as requiring various inorganic nutrients, such as carbon dioxide, phosphorus and fixed nitrogen (2).

Conservation Status

Not listed under the IUCN Redlist (4).


Description written by Ben Harvey (2009)

(1)   Cabioc’H, J., Floc’H, J. & Le Toquin, A., 1992. Guide mes algues des mers d’Europe. Paris: Delachaux et Niestle.

(2)   Graham, L.E. & Wilcox, L.W., 2000. Algae. New Jersey: Prentice-Hall Inc.

(3)   Guiry, M.D. (2009). Cystoseira C. Agardh, 1820. In: Guiry, M.D. & Guiry, G.M. (2009). AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Accessed through the World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=144126 on 2009-09-02

(4)   IUCN, 2009. IUCN Red List of Threatened Species. [Online] (2009.1) Available at: www.iucnredlist.org [Accessed 01 September 2009].

(5)   Europe, C.o., 2002. Convention on the conservation of European wildlife and natural habitats: Bern Convention. [Online] Available at: http://conventions.coe.int/Treaty/FR/Treaties/Html/104-1.htm [Accessed 02 September 2009].