Acropora tenuis Propagation Guide
Fragging and propagation of Acropora tenuis, a corymbose small-polyp stony coral with tube-shaped axial corallites, increased by branch-tip cuttings in the reef aquarium.
Overview
Acropora tenuis is a small-polyp stony coral of the family Acroporidae. According to Wikipedia it occurs in corymbose colonies containing orderly-spaced branchlets, with tube-shaped axial corallites and radial corallites that have flaring lips. It is blue, cream, yellow or green in colour and is found across the Indian Ocean and central Indo-Pacific at depths of 8 to 20 metres on upper reef slopes; the popular Cali Tort is an aquarium morph of this species.
Reproductive Mode
Wikipedia records that Acropora tenuis is a simultaneous hermaphrodite, so colonies produce both eggs and sperm. In aquaria the practical route is asexual fragmentation, which preserves the parent's symbiotic zooxanthellae and coloration. Captive propagation of Acropora is widespread in the reef-keeping community.
Fragging / Asexual Propagation
Cut or snap a branch tip of roughly 2-5 cm with bone-cutters and mount it to a frag plug with cyanoacrylate gel or epoxy. The tube-shaped axial corallite at the tip drives upward growth, so leaving it intact speeds recovery. 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 supplementation, and clean turbulent water. Place tenuis frags under high light and strong flow with stable alkalinity, calcium and magnesium and low nutrients to encourage encrustation and branching.
Sexual Reproduction
Wikipedia states spawning in A. tenuis occurs annually and is synchronised among colonies in any one locality: packets of eggs and sperm are released into the water column and, being buoyant, rise to the surface for external fertilisation. This broadcast mass-spawning is generally not reproduced in home aquaria.