Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Gigartinales

Family Gigartinaceae

Chondracanthus acicularis (Roth) Fredericq in Hommersand, Guiry, Fredericq & Leister 1993: 117

Thalli prostrate or erect, firm to cartilaginous, dark reddish-purple, sometimes with white or green spots, up to about 100 mm long, but often smaller. Holdfast gives rise to several fronds, branching pinnate to irregular, branches 1 (-2) mm wide, cylindrical to compressed, curved, branch tips very pointed; Branches may attach secondarily to substratum. Holdfast initially discoid but may become stoloniferous. Structure multiaxial; medulla of compact thick-walled filaments; cortex of radial filaments of small cells (about 6 µm in diameter). Spermatangia not seen. Cystocarps forming swellings near apices. Tetrasporangia embedded in inner cortex in sori, producing dark slightly swollen areas, cruciately divided, 20-40 µm long.

Collections, ecology and regional distribution

Found from De Hoop to Cape Morgan in the Eastern Cape (24-40). Often associated with sand.

World distribution: widespread in tropical and temperate seas.

Type locality: Adriatic Sea (Dixon & Irvine 1977).

Note: 1. The genus Chondracanthus was resurrected by Hommersand et al. (1993); this species was previously known as Gigartina acicularis (Roth) Lamouroux. According to Hommersand et al. (1993) the centre of distribution of the genus Chondracanthus is the eastern North Pacific Ocean.

2. There are several specimens in BOL from the Kowie and labeled Gigartina teedei but later annotated “G. acicularis” by G.F. Papenfuss. These specimens fit the description of C. acicularis, and closely resemble European and larger local specimens of C. acicularis. We conclude that Chondracanthus teedei does not occur on the south coast.

 

Chondracanthus acicularis, De Hoop intertidal zone.

Chondracanthus acicularis, detached clump of thalli.

 

References Chondracanthus

Dixon, P.S. & Irvine, L.M. 1977. Seaweeds of the British Isles. Volume 1. Rhodophyta. Part 1. Introduction, Nemaliales, Gigartinales. pp. [i]v-xi, [1]4-252, 90 figs. London: British Museum (Natural History).

Hommersand, M. H., Guiry, M. D., Fredericq, S. & G. L. Leister. 1993. New perspectives in the taxonomy of the Gigartinaceae (Gigartinales, Rhodophyta). Hydrobiologia 260/261: 105-120.

 

Cite this record as:

Anderson RJ, Stegenga H, Bolton JJ. 2016. Seaweeds of the South African South Coast.
World Wide Web electronic publication, University of Cape Town, http://southafrseaweeds.uct.ac.za; Accessed on 19 December 2024.