As shown in the SEM micrographs in Fig. 1A, the cells have
meridional ribs on the cell wall at the three stages examined,
and these ribs converged at two poles of the cells. Whether these
ribs have any function is not clear, but they are an important morphological
character typical to the genus Coelastrella (Hanagata,
1998). In addition, the phenotype of reddish pigments production
is also similar to that of Coelastrella striolata (Abe et al., 2007),
which was reported to synthesise carotenoids. The 18S rDNA of
this new species was therefore sequenced to compare to those of
similar species in GenBank. As shown in Fig. 2, this new species
was grouped in one clade with other Coelastrella species while
Scenedesmus species were placed in another based on similarities
of their 18S rDNA sequences. This new species was therefore tentatively
named as Coelastrella sp. F50.