It has been shown that most green a

It has been shown that most green algae grow in the epilittoral or upper zone of water; however brown algae grow often in deeper water and many red algae can be described as subtidal algae [23, 24]. In the subtidal zone, where B and G light prevails, the specific photopigment of the red algae allows efficient absorption [25]. In addition, several red algal species growth rates and photosynthesis depend on the light quality during the culture period and on the pigment composition under these conditions [19]. Although the light requirements were very low in G and B light for all red algae analyzed, the action spectrum of growth followed the photosynthetic action spectrum, with maximum efficiencies in G and B wavebands, corresponding to the spectrum distribution occurring in deep coastal seawater [19]. Nonetheless, contrary to our results, Kim et al. [26] reported thatGracilaria tikvahiae presented an inferior growth rate for algae grown under B light as compared to those grown under R, G,and fluorescent light. This could be due to algae absorption characteristics depending also on several other factors, especially the thallus morphology, thickness, structure of photosynthetic system, and so forth, as it applies more to coastal waters than oceanic waters [27].