CODIACEAE, Kutzing, 1843

Mead, A., Carlton, J. T., Griffiths, C. L. & Rius, M., 2011, Introduced and cryptogenic marine and estuarine species of South Africa, Journal of Natural History 45 (39 - 40), pp. 2463-2524 : 2509-2510

Family CODIACEAE

Codium fragile fragile (Suringar, 1867) Introduced (= invasive strain tomentosoides (van Goor) P. C. Silva 1955)

Under the name Codium fragile ssp. tomentosoides , this green alga has been dispersed out of Asia to numerous coasts around the world in the 1800s and 1900s ( Provan et al. 2005), resulting in an extensive literature on its distribution, dispersal vectors, and ecological impacts. Recent molecular work ( Provan et al. 2008) combined with attendance to botanical nomenclatural rules have led to the necessary but cumbersome new name Codium fragile fragile invasive tomentosoides strain. Provan et al. (2005) reported that this non-native Codium was “reported recently” in South Africa, citing Dromgoole (1982) and Chapman (1999), neither of which paper reports South Africa as a location for this taxon. Provan et al. (2008) stated that this alga had recently been reported from South Africa “in 1999”, citing Begin and Scheibling (2003). However, Begin and Scheibling (2003) cite Trowbridge (1998) as the source of that record, but such a record does not appear in Trowbridge’s paper, and the citation was based on a mis-reading of that paper (R. Scheibling, personal communication, 2007).

However, Provan et al. (2008) discovered that material of Codium collected in 1937 at “Melkbosch” (Melkbos, or Melkbosstrand, just north of Cape Town) in South Africa by the well-known phycologist G. F. Pappenfuss was the invasive strain tomentosoides. Ironically, this material consisted of the type specimens of Codium fragile ssp. capense Silva, 1959 , a taxon which is still recognized, based upon other material from South Africa that is not tomentosoides ( Provan et al. 2008).

Stegenga et al. (1997) note that Codium fragile ssp. capense is “a species of the sublittoral fringe and intertidal rockpools” occurring “along the whole of the Cape west coast and most of Namibia, eastward as far as Robberg (Plettenberg Bay).” It seems probable that within these populations the tomentosoides strain has gone unrecognized so we retain it in the South African invasive algal flora pending further collections from the Melkbosstrand and other regions.