Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Nemaliales

Family Galaxauraceae (see Huisman et al., 2004)

Dichotomaria diesingiana (Zanardini) Huisman, J. T. Harper & G. W. Saunders 2004: 230

Thallus erect, pinkish-red to brownish-red, up to 25 cm tall, dichotomously branched, moderately calcified; lower 1-2 cm usually terete and hirsute, remainder flattened, 2-5 (-7) mm wide, frequently branched, often rugulose, unsegmented, apices rounded. Internal structure comprising medulla of interwoven filaments 10-15 µm in diameter, cortex of gametophytes and tetrasporophytes somewhat different in structure. Cortex of tetrasporophytes with inner region of two layers of large globose or subglobose cells and outer region of ovate or clavate pigmented epidermal cells borne on stalk cells; tetrasporangia cruciately divided, borne on short stalk cells. Cortex of gametophytes with 3-4 layers of compact large cells that decrease in size towards exterior.

Collections, ecology and regional distribution

Epilithic in the lower eulittoral and shallow sublittoral (to at least 14m), mainly in wave-exposed localities. Recorded from Arniston along the south coast and the whole Kwazulu-Natal coast.

World distribution: Also recorded from Mozambique (Papenfuss et al. 1982).

Type locality: Port Natal (Durban) (Silva et al 1996).

Note: This and other South African Dichotomaria species (as Galaxaura) are described in detail by Papenfuss et al (1982).

 

Dichotomaria diesingiana, shallow subtidal, Haga Haga.

 

References Dichotomaria diesingiana

Huisman, J. M., Harper J. T. & G. W. Saunders 2004. Phylogenetic study of the Nemaliales (Rhodophyta) based on large-subunit ribosomal DNA sequence supports segregation of the Scinaiaceae fam, nov. and resurrection of Dichotomaria Lamarck Phycological Research 52(3): 224-234.

Papenfuss, G. F., Mshigeni, K. E. & Y.-M. Chiang 1982. revision of the red algal genus Galaxaura with special reference to the species occurring in the western Indian Ocean. Botanica Marina 25: 401-444.

Silva, P.C., Basson, P.W. & Moe, R.L. (1996). Catalogue of the benthic marine algae of the Indian Ocean. University of California Publications in Botany 79: 1-1259.

 

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.