The genus Planococcus refers to a group of coccolithophores, which are unicellular algae that form tiny calcareous plates around their cells. These plates are responsible for the white or pale blue color of the organisms. Planococcus species are commonly found in tropical and subtropical waters and can play an important role in marine ecosystems, as they are a food source for many other marine organisms. While there are no widely accepted synonyms for the genus Planococcus, it is important to note that different taxonomic classifications may group Planococcus species with other related genera or subgenera, depending on their genetic and morphological characteristics.