Gonyaulax polyedra

Figure 30-2 Gonyaulax dyedra

Gonyaulax polyedra, a single-celled marine alga belonging to the dinoflagellates, is a close relative of G. catanella, which causes poisoning in shellfish. Gonyaulax polyedru is bioluminescent, the light reaching a peak in the middle of the night. Photosynthesis, conversely, peaks in the middle of the day, and cell division is restricted to the hours before dawn. If G. polyedru is kept in constant conditions, it will reproduce numerous times, making available cells that have never before existed in conditions of both day and night. These organisms exhibit the same circadian behaviors for scores of generations, that is, producing maximum light in the middle of the night, demonstrating peak photosynthesis in the middle of the day, and reproducing just prior to dawn.