Monterey Bay Aquarium Research Institute
Marine Botany

Codium Structure and Reproduction


Codium fragile is 10 to 30 centimeters tall with several erect branches from a broad basal disk. The "fingers" are branched and as thick as a pencil or finger. The branches float in the water when covered and hang down when the tide is out. Under a microscope, one can see that each "finger" is made up of many fine filaments woven together. On the outside, the filaments give rise to swollen utricles. These utricles are club-shaped, ending in a point. They are full of photosynthetic chloroplasts. Epiphytic red algae often grow on the tips of the utricles:


Unlike many algae and other plants, Codium has only a gametophyte generation. The eggs and sperm are found in separate chambers called gametangia which project off the utricles:


Most species of Codium are dioecious, with the male and female gametangia on separate plants. Each of the gametes has two flagella, and the female gametes are larger than the male gametes.

Kathy's Codium pages                                                          copyright Kathy Tyson 1996.

Last updated: Feb. 05, 2009