Acropora gemmifera: Propagation Guide
Propagating Acropora gemmifera, a digitate Acropora with thick tapering branches: fragging axial tips, the light and flow it needs, and the genus's broadcast spawning.
Overview
Acropora gemmifera occurs in digitate colonies consisting of thick tapering branches, each with a single axial corallite at the branch terminus and incipient axial corallites toward the base. It was originally described by Brook in 1892 as Madrepora gemmifera and is classified in the family Acroporidae. It ranges widely across the Red Sea and Indo-Pacific on exposed upper reef flats and slopes at depths of 1-15 m, and is assessed as Least Concern on the IUCN Red List.
Reproductive Mode
Like other Acropora, A. gemmifera reproduces sexually as a hermaphroditic broadcast spawner and asexually by fragmentation. In aquaculture, fragmentation is the practical method and reproduces the colony's color and digitate form faithfully.
Fragging / Asexual Propagation
- Choose a healthy colony with several thick growing branches.
- Cut or snap a branch tip a few centimetres long with bone cutters; the axial corallite sits at the tip.
- Mount the frag to a plug or rock with cyanoacrylate glue or a peg.
- Return it to bright light and strong turbulent flow so it can encrust and regenerate an axial corallite.
Conditions for Propagation
Acropora requires bright light, stable temperatures, regular calcium and alkalinity dosing, and clean turbulent water. Because A. gemmifera naturally occupies exposed upper reef flats, strong flow and intense light suit it well and aid fragment recovery.
Sexual Reproduction
As a hermaphroditic broadcast spawner, A. gemmifera releases buoyant gamete bundles of eggs and sperm during mass synchronized spawning. The bundles float to the surface, break apart and fertilise externally, producing larvae used in reef restoration. This is uncommon in aquaria, where fragmentation is standard.