Plexaura flexuosa (Caribbean Sea Rod) Propagation Guide

Propagating the photosynthetic Caribbean gorgonian Plexaura flexuosa by cutting a branch section and securing it to rock or a plug, with notes on octocoral reproduction and care.

Overview

Plexaura flexuosa is a gorgonian-type octocoral in the family Plexauridae and one of the photosynthetic Caribbean gorgonians, sometimes sold as a purple candelabra. As an octocoral it grows as a colony of polyps, each with eight feathery tentacles, supported on a flexible branching axis, and it carries symbiotic zooxanthellae that supply much of its energy from light.

Reproductive Mode

Octocorals have a complex life cycle with a motile planktonic larva, the planula, and a later sessile phase; the gonads sit near the base of each mesentery. Sexual reproduction therefore proceeds through gamete release and a free-swimming larval stage. In the aquarium, gorgonians are multiplied asexually instead, by cutting and re-securing branch sections.

Fragging / Asexual Propagation

To frag a sea rod, take scissors or cutters and cut off a branch section; a cut to a healthy colony does no harm to the rest of it. Secure the cutting to a plug or rock, since most gorgonians encrust onto plugs quickly. Dry the base of the cutting and the plug, add a couple of dabs of cyanoacrylate glue, and stand the piece upright; gorgonians are best placed freestanding and secured to rock.

Conditions for Propagation

Good water flow is one of the most important factors in keeping gorgonians, because strong current removes the mucus membrane the colony periodically sheds and supports polyp extension. Photosynthetic gorgonians also need moderate to high lighting for several hours a day. A freshly secured cutting recovers fastest under brisk flow and good light while it encrusts onto the plug.

Common Challenges

Insufficient flow lets mucus accumulate and algae settle on a fresh cutting, so keep current strong and turbulent. Basting the cutting to clear shed mucus helps the polyps re-extend and the base attach cleanly to the plug or rock.