Pseudoplexaura porosa

The porous sea rod, also known as the porous false plexaura, is a gorgonian octocoral from the family Plexauridae. It lives in the Caribbean Sea and the Gulf of Mexico. This coral forms large, upright, tree-like colonies that can grow to about 2.25 meters tall, with a trunk up to 5 centimeters thick. The branches fork repeatedly into equal pairs, are smooth, and end in long, slightly tapered tips about 4 millimeters thick. These tips are soft and slimy. The polyps have eight tentacles each, project from large, crowded apertures arranged in a spiral up the branches, and overlap one another. The colony’s color ranges from pale yellow to tan or reddish-purple.

The species is found from Bermuda and Florida down to Colombia, typically on reefs between 3 and 6 meters deep, though it has been recorded as deep as 280 meters. It thrives in strong currents, and its flexible branches sway with the water. The polyps extend their tentacles day and night to feed on plankton and organic particles. The coral hosts photosynthetic zooxanthellae (single-celled protists) in its tissues, which provide nutrients. The polyps can retract defensively and are armed with nematocysts. Few predators feed on it; these include the flamingo tongue snail, nudibranchs, butterflyfish, and some angelfish.

Colonies are either male or female. On nights about five days after a full moon in summer, regulated by the lunar cycle, mature colonies release gametes into the water. Fertilized eggs develop into planula larvae, which sink to the seabed five days later and metamorphose into new colonies. These new colonies are soon colonized by zooxanthellae and grow by budding. Pieces of coral can also detach and attach to the substrate to form new colonies. The species can live for several decades, and its main cause of death is detachment from the seabed during tropical storms.

Several substances have been isolated from its tissues, including crassin acetate, a diterpene lactone first obtained from this coral and found in very high concentrations in its zooxanthellae. Other diterpenoids from *Pseudoplexaura porosa* show cytotoxic antitumor activity when tested against human tumor cells.