Benthic marine cyanophyceae from Kwa-Zulu Natal, South Africa

The marine Cyanophyceae of southern Africa are inadequately documented. Research along the Kwa-Zulu Natal Coast involved examining various marine substrata for cyanophytes, utilizing Provasoli's enriched culture medium at 20°C and 20 µmol m-2 sec. A total of sixty-six taxa were identified, with eight not thriving in either enrichment or unialgal cultures. Two were studied exclusively from enrichment cultures, while six were based solely on wild material. The identified taxa span three orders, fourteen families, and thirty-four genera. Notably, fifteen genera and thirty species are recorded for the first time in South Africa. The isolated taxa were analyzed under varying photon flux densities and temperature conditions, revealing morphological and size variations. Approximately twenty-nine percent of specimens exhibited morphological differences, alongside size variations in structures like vegetative cells, heterocytes, and akinetes. Statistical tests confirmed significant differences at the 5% level. The findings indicate that certain taxonomic characteristics of Cyanophyceae may not be stable and can vary with environmental and cultural conditions.