Acropora samoensis Propagation Guide

How to propagate Acropora samoensis, a compact-branching SPS coral, through asexual fragmentation: cutting branch tips, mounting frags, and the stable chemistry and lighting fragments require to heal.

Overview

Acropora samoensis is a compact-branching stony coral in the family Acroporidae. Like other Acropora, it is a colony of small polyps that share tissue and build a calcium carbonate skeleton, while symbiotic algae (Symbiodinium) living in the coral's cells produce energy through photosynthesis. Its fine branch structure makes it well suited to the branch-tip fragging used to multiply small-polyp stony (SPS) corals in captivity.

Reproductive Mode

Acropora reproduce both sexually, by releasing gametes into the water, and asexually, when broken branches reattach and form new colonies. Aquarium propagation relies on the asexual route: a branch fragment carries the same genetics as the parent and continues growing once secured to a surface.

Fragging / Asexual Propagation

Select a healthy, fully coloured branch tip from an established colony.
Cut or snap the tip with bone cutters or a saw; a clean break heals faster.
Glue the fragment to a plug or rock with cyanoacrylate or two-part epoxy.
Place the frag under moderate light and flow, then move it up as tissue grows over the cut.
Dip new frags before adding them to a display to reduce the risk of pests and disease.

In a well-maintained reef aquarium, finger-sized Acropora fragments can grow into much larger colonies within one to two years, so a single healthy parent yields many frags over time.

Conditions for Propagation

Healing fragments need stable conditions above all else. Acropora are especially susceptible to bleaching when stressed, which is caused by the loss of their zooxanthellae, so swings in temperature, salinity, alkalinity, calcium and magnesium must be avoided. High light and high flow support the dense skeletal growth this branching form depends on.

Sexual Reproduction

In the wild, Acropora participate in annual mass-spawning events, releasing eggs and sperm into the water column where fertilisation and larval development occur. This broadcast spawning is rarely reproduced in home aquariums, which is why hobby propagation depends on fragmentation.