Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Ceramiales

Family Rhodomelaceae

 

Herposiphonia prorepens (Harvey) F. Schmitz 1895: 158

Plants bright to dark red, prostrate. Indeterminate axes attached by digitate haptera. Haptera not more than one per segment, often at regular intervals of two or three segments. Segments of main axis about as long as broad, with 12 pericentral cells. Indeterminate laterals arising laterally from main axis, alternate, often stunted. Determinate laterals in single dorsal row, apices acute, compressed, 300-2000 µm high and 100-160 µm wide, consisting of 15-27 segments each 0.3-0.5 times as long as broad; number of pericentral cells 10(-12), basal segment with four pericentral cells.

Tetrasporangia ca. 180x120 µm, one per segment in rectilinear series of rarely more than five, developing in segments 5-13 of branchlets that at maturity are closely packed. Antheridial stands on segments 6-11, abaxial. Cystocarps 700-800 x 500-600 µm, ovate to urn-shaped, one per determinate lateral, on segments 6-10.

Collections, ecology and regional distribution

Recorded from Cape Hangklip (120 km west of Cape Agulhas) to the Durban area of Kwazulu-Natal (19-51). Usually epiphytic on species of Amphiroa, especially A. ephedraea, from the eulittoral and shallow subtidal zones.

World distribution:A lso recorded from Chagos Archipelago, India, Indonesia (Silva et al. 1996).

Type locality: Algoa Bay, South Africa (Silva et al. 1996).

Notes: Wynne (1984) points out that Harvey’s (1862) record of H. prorepens from Australia does not refer to this species. Also, Stegenga et al. (1997) consider this species to include H. akidoglossa, described from Kwazulu-Natal by Norris (1992).

 

Herposiphonia prorepens, on Amphiroa sp, fresh material, Nature’s Valley.

Herposiphonia prorepens, fresh material, Nature’s Valley.

Herposiphonia prorepens, showing dorsal row of determinate laterals (stained slide).

Herposiphonia prorepens, apex of thallus (stained slide).

Herposiphonia prorepens, tetrasporangia (stained slide).

Herposiphonia prorepens, cystocarp borne laterally on determinate branchlet (stained slide).

Herposiphonia prorepens. 1. Microscopic habit. 2. Detail of prostrate axis and determinate laterals. 3. Haptera beneath prostrate axis. 4. Tetrasporiferous branchlet. Reproduced from Stegenga et al. (1997).

 

References Herposiphonia prorepens

Harvey W. H. 1862. Phycologia Australica. Vol. 4, pl. 181-240. Reeve, London.

Norris R. E. 1992. Six marine macroalgal genera new to South Africa. South African Journal of Botany 58: 2-12.

Schmitz, F. 1895. Marine Florideen von Deutsch-Ostafrica. Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 21: 137-177.

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.

Stegenga, H., Bolton, J.J. & R. J. Anderson. 1997. Seaweeds of the South African west coast. Contributions from the Bolus Herbarium 18: 655 pp.

Wynne, M.J. 1984. Notes on Herposiphonia (Rhodomelaceae, Rhodophyta) in South Africa, with a description of a new species. Cryptogamie, Algologie 5: 167-177, 12 figs.

 

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 25 April 2024.