In this study, the influence of the light intensity on total chlorophyll, total carotenoids, phycocyanin, phycoerythrin and protein content of Gracilaria verrucosa (Hudson) Papenfuss were examined. Five different light intensities were arranged, e.g. 25 (group 1), 50 (group 2), 75 (group 3), 100 (group 4), and 150 (group 5) mu mol photons m(-2) s(-1). Maximum total chlorophyll (5.70 +/- 0.10 mg g(-1) ww), phycoerythrin (5.39 +/- 0.44 mg g(-1) ww) and phycocyanin (3.31 +/- 0.19 mg g(-1) ww) contents were achieved in group 1 whereas the highest total carotenoids content was found in group 5 (1.62 +/- 0.04 mg g(-1) ww). There was a statistically significant difference between the experimental groups (p<0.05). A significant positive correlation was found between total chlorophyll and carotenoids content as well as total chlorophyll content and light intensities (p<0.05). It was found that total chlorophyll content was strongly correlated with phycocyanin and phycoerythrin contents (p<0.05). The phycobiliproteins (phycocyanin + phycoerythrin)/total chlorophyll ratio significantly increased when the light intensity decreased. The maximum protein content was determined in group 1 (24.19 +/- 0.28 %), and statistically significant differences were determined among the groups (p<0.05). Because G. verrucosa adapts different light regimes in a short time period, it is a potential candidate for Integrated Multitrophic Aquaculture (IMTA) systems, and it can be cultured at different water depths in these systems.