Light and Electron Microscopic Observations on Erythrolobus coxiae gen.et sp.nov. (Porphyridiophyceae, Rhodophyta) from Texas U.S.A.

Abstract

Species of the unicellular red algae Dixoniella, Flintiella, Glaucosphaera, Porphyridium, Rhodosorus and Rhodella have been formally described and their fine structure investigated by transmission electron microscopy (TEM; Broadwater and Scott 1994) while the unicellular genus Rhodospora (Geitler 1927, Johansen et al. 2005) is described only at the light microscopic level. Several other new species and genera of unicellular red algae have also been isolated and briefly examined by molecular analysis and light and electron microscopy (Hara et al. 2000, Yokoyama et al. 2004) and formal description of several of these is currently underway (Yokoyama and Hara, personal communication). Recently our understanding of phylogenetic interrelationships of red algal unicells has progressed significantly using molecular techniques in combination with several TEM features (Hara et al. 2000, Saunders and Hommersand 2004, Yoon et al. 2006). Ultrastructural features considered most valuable in unicellular red algal systematics include Golgi apparatus associations with other organelles, presence or absence of pyrenoids and pyrenoid attributes, the morphology and precise details of chloroplasts and certain details of nuclei and mitosis (Broadwater and Scott 1994). In the mid-1970s a unicellular red alga believed to be a new genus was isolated from coastal Texas USA. Initial work describing growth characteristics and behavior in culture, phycobilin pigments and light and electron microscopy was completed but the results were not published (see Baca 1978). Recently, we conducted microscopic studies on this strain in order to formally describe this new coccoid red alga as Erythrolobus coxiae nov.gen et nov. sp. Algae Volume 21(4): 407-416, 2006