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Order Ectocarpales

Family Chordariaceae

Elachista Duby

Small, epiphytic thalli comprising an adpressed basal layer and erect branched filaments. Reproductive structures borne terminally or laterally in filaments, plurilocular sporangia uniseriate, unilocular sporangia obovate. There are 24 currently recognised species worldwide.

One species of Elachista, E. endarachnae, was described from the south coast (Stegenga et al. 2002), but later ascribed to the new genus Elachistiella (Cassano et al. 2004; see under Elachistiella endarachnae), the latter genus based on its possession of two types of plurilocular structures: multiseriate “ectocarpoid” structures developing from the apices of filaments, and intercalary structures. Stegenga et al. (2002) note the occurrence of “at least two more species of Elachista on the South African south coast” that could not be described on account of insufficient material. Two pressed specimens in BOL, epiphytic on Sargassum spp., appear similar to Elachista nigra Takamatsu, a species from Japan, California and Australia that possesses only apical plurilocular structures (e.g. see Womersley 1987). In addition to noting these, we briefly describe a third species below.

Elachista species indet.

Parenchymatous basal part very small, vegetative filaments rather sparse, often somewhat curved, to 600 x 22,5 μm, the cells about as long as broad, somewhat swollen. Plurilocular sporangia abundant, uniseriate, consisting of 4-10 cells, measuring up to 35 x 7.5 μm.

Collections, ecology and regional distribution

Found once at Cape Padrone, 26-10-2003 (slide EC1935), epiphytic on Sargassum (or possibly Cystoseira sp. – identity of host uncertain).

 


Elachista sp, Cape Padrone, stained slide material.


Elachista sp, Cape Padrone, stained slide material.

 

References Elachista

Cassano, V., Yoneshigue-Valentin, Y. & Wynne, M. J. (2004). Elachistiella leptonematoides gen. et sp. nov. (Elachistaceae, Phaeophyceae) from Brazil. Phycologia 43: 329-340.

Stegenga, H., Bolton, J. J. & Anderson, R. J. (2002). Elachista endarachnae sp. Nov. (Phaeophyceae, Elachistaceae), a peculiar representative of the genus in South Africa. Phycologia 41: 432-435.

Womersley, H.B.S. (1987). The marine benthic flora of southern Australia. Part II. pp. 481, 169 figs, 1 table, 8 plates, 4 maps. Adelaide: South Australian Government Printing Division.

 

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 November 2018.