Other algae occurring symbiotically in reef organisms include a diversity of cyanobacteria (Prochloron), chlorophytes (zoochlorellae), diatoms, rhodophytes, chrysophytes, and even free, ephermal chloroplasts from chlorophytes and rhodophytes. Algal symbionts have been found in a variety of hosts, including other algae, ciliates, foraminifera, sponges, cnidarians, flatworms, molluscs, echinoderms, and ascidians;
p.309; in ....
Paulay G.; 1997; Diversity and Distribution of Reef Organisms; in Birkeland C. (ed.); Life and Death of Coral Reefs; Chapman and Hall London - UK;