Acropora pulchra Propagation Guide
Fragging and propagation of Acropora pulchra, a bushy branching small-polyp stony coral that also fragments naturally, increased by branch-tip cuttings in the reef aquarium.
Overview
Acropora pulchra is a small-polyp stony coral of the family Acroporidae. Wikipedia describes it as a branching species, sometimes tree-like, with branches up to 12 mm in diameter and up to 18 cm long and widely spaced corallites with elongated lower lips. Its colour varies from blue to shades of brown, often with pale blue tips, and it grows from 1 to 20 metres deep on back-reef fringes, flats and lagoons across the Indo-Pacific.
Reproductive Mode
Wikipedia records that Acropora pulchra reproduces asexually through fragmentation as well as sexually. In aquaria fragmentation is the practical route and preserves the symbiotic zooxanthellae and coloration of the parent. 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 axial corallite at the branch tip leads 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 pulchra frags under high light and strong flow with stable alkalinity, calcium and magnesium and low nutrients; this fast-growing bushy species encrusts and branches readily.
Sexual Reproduction
Wikipedia states Acropora pulchra synchronises its reproductive activity with the phase of the moon so that all corals in one locality spawn on the same couple of days, releasing buoyant gametes into the water column for external fertilisation. This broadcast mass-spawning is generally not reproduced in home aquaria.