Acropora echinata Propagation Guide
Fragging and propagation of Acropora echinata, a bottlebrush-form small-polyp stony coral with thin radial branchlets, increased by branch-tip cuttings in the reef aquarium.
Overview
Acropora echinata is a small-polyp stony coral of the family Acroporidae. Wikipedia describes its colonies as made of flat, bottlebrush-like branches with thin, neatly-arranged branchlets; tips are blue or purple while the body is white or cream, and some specimens are entirely blue. The incipient axial and axial corallites are indistinguishable and the radial corallites are tube-shaped and short. It occurs in sheltered shallow reefs at 8 to 25 metres in clear water.
Reproductive Mode
Acropora reproduce both asexually and sexually. In the aquarium A. echinata is multiplied by fragmentation, which preserves the parent's symbiotic zooxanthellae and coloration. Wikipedia notes that captive propagation of Acropora is widespread in the reef-keeping community.
Fragging / Asexual Propagation
Cut or snap a branch tip of about 2-5 cm with bone-cutters and bond it to a frag plug with cyanoacrylate gel or epoxy; the thin bottlebrush branchlets are fragile, so handle gently. The axial corallite at the branch tip drives regrowth, so an intact tip encrusts and elongates fastest. Wikipedia reports finger-sized Acropora fragments can grow into medicine-ball-sized colonies in one to two years under good reef conditions.
Conditions for Propagation
Wikipedia states Acropora requires bright light, stable temperatures, regular calcium and alkalinity dosing, and clean turbulent water. Place echinata frags under high light and strong flow with stable alkalinity, calcium and magnesium and low nutrients to encourage encrustation onto the plug and new branchlet development.
Sexual Reproduction
In the wild Acropora reproduce by annual synchronised broadcast mass-spawning, releasing buoyant packets of eggs and sperm into the water column for external fertilisation. This event is generally not reproduced in home aquaria, where propagation relies on fragmentation.