Chrysophyceans
Chrysophyceans are also known as the "golden algae". As suggested by their colour, they are close relatives of diatoms, but also, counterintuitively, of the yellow-green xanthophyceans. All of these groups share some ultrastructural characteristics differing from those of green plants, and lack chlorophyll b in their chloroplasts.
Although chrysophyceans contain chloroplasts, the site of photosynthesis (manufacture of sugars and oxygen from CO2 and water using light energy), many species are also able to absorb organic food compounds directly from their environment (including the engulfment of whole cells).
Relationships within the golden algae are historically confused. Here we adopt a broad concept of the group, with includes the distinctive Synura, the whole colony of which is motile. Other forms are Chrysocapsa, which forms mucilaginous non-motile colonies, and Dinobryon, a remarkable branched colony of cells each encased in an individual lorica.
