1. Key words: roots, evolution, adaptations, structure, symbioses.

2. Therefore, the MAAs found in many Anthozoan/dinoflagellate symbioses are widely assumed to originate in the endosymbionts (Shick and Dunlap, 2002), even though they actually may be more concentrated in the tissues of the Anthozoan host than in the zooxanthellae (Shick et al., 1995; J