Bolidophyceae is a class of photosynthetic heterokont picophytoplankton, and consist of less than 20 known species. They are distinguished by the angle of flagellar insertion and swimming patterns as well as recent molecular analyses. Bolidophyceae is the sister taxon to the diatoms (Bacillariophyceae). They lack the characteristic theca of the diatoms, and have been proposed as an intermediate group between the diatoms and all other heterokonts.
Bolidophyceae
The silicified Tetraparma pelagica
The silicified Triparma laevis f. inornata
The silicified Pentalamina corona
The Stramenopiles, also called Heterokonts, are a clade of organisms distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have been secondarily lost. Stramenopiles represent one of the three major clades in the SAR supergroup, along with Alveolata and Rhizaria.
Two living C. roenbergensis. Light micrograph. The cells are about 6 µm long. The anterior flagellum beats with an undulating pattern, the posterior (recurrent or smooth) flagellum usually holds the cell to the substrate.
Giant kelp, Macrocystis pyrifera, an example of a multicellular stramenopile, is a large seaweed, up to 45 metres (150 feet) long, in the Phaeophyceae, within the Gyrista.
Electron micrograph of the protist Paraphysomonas butcheri. It illustrates the stramenopile property – of having stiff hairs. The hairs attach to one longer flagellum, the other is without hairs (an arrangement also called 'heterokont', meaning "unequal"). The body of the flagellate is coated with delicate scales. Paraphysomonas feeds on bacteria, two of which lie near the hairy flagellum.
