The raphidophytes, formally known as Raphidophycidae[2]orRaphidophyceae (formerly referred to as Chloromonadophyceae and Chloromonadineae),[3] are a small group of eukaryoticalgae that includes both marine and freshwaterspecies.[4] All raphidophytes are unicellular, with large cells (50 to 100 μm), but no cell walls. Raphidophytes possess a pair of flagella, organised such that both originate from the same invagination (or gullet). One flagellum points forwards, and is covered in hair-like mastigonemes, while the other points backwards across the cell surface, lying within a ventral groove. Raphidophytes contain numerous ellipsoidchloroplasts, which contain chlorophylls a, c1 and c2. They also make use of accessory pigments including β-carotene and diadinoxanthin. Unlike other heterokontophytes, raphidophytes do not possess the photoreceptive organelle (or eyespot) typical of this group.
In terms of ecology, raphidophytes occur as photosyntheticautotrophs across a range of aquatic systems. Freshwater species are more common in acidic waters, such as pools in bogs. Marine species often produce large blooms in summer, particularly in coastal waters. Off the Japanese coast, the resulting red tides often cause disruption to fish farms, although raphidophytes are not usually responsible for toxic blooms.
^ abcCavalier-Smith, T; Scoble, J. M. (2013). "Phylogeny of Heterokonta: Incisomonas marina, a uniciliate gliding opalozoan related to Solenicola (Nanomonadea), and evidence that Actinophryida evolved from raphidophytes". European Journal of Protistology. 49 (3): 328–353. doi:10.1016/j.ejop.2012.09.002. PMID23219323.
^Herbert Graffius, J. (1966). "Additions to Our Knowledge of Michigan Pyrrhophyta and Chloromonadophyta". Transactions of the American Microscopical Society. 85 (2): 260–270. doi:10.2307/3224637. JSTOR3224637.
^ abYamaguchi, Haruyo; Nakayama, Takeshi; Murakami, Akio; Inouye, Isao (2010). "Phylogeny and taxonomy of the Raphidophyceae (Heterokontophyta) and Chlorinimonas sublosa gen. et sp. nov., a new marine sand-dwelling raphidophyte". Journal of Plant Research. 123: 333–342. doi:10.1007/s10265-009-0281-1.
