Anacropora is a delicate, thin branching stony coral which is greatly underrepresented in the aquarium hobby. However in the wild, the fast-growing thin branches of Anacropora species can all but take over certain habitats.
Closely related to Acropora and Montipora, Anacropora is the physical embodiment of a blend of the two with corallites that are somewhat exert on the sides of branches but they don’t terminate into an axial polyp the way that the iconic Acros do. Despite not having a terminal axial corallite, Anacropora still grows extremely fast and with its thin and closely branching colonies, the amount of calcium carbonate that Anacropora can put down is quite simply amazing.
The first time we encountered “fields” of Anacropora there was not a single erect colony to be seen but instead, the bottom was literally made up of loose living branches of Anacropora which was intermixed with the also-branching Cyphastrea decadia. This kind of scenery was not exactly breathe taking and it took a coral junkie to take a second look at the seafloor to see that it was actually made up of loose living coral.
For a time we presumed this was perhaps a dominant way that Anacropora is encountered but as with many of our coral observations this summer, on the Fluval Sea Flores Expedition we observed fields of whole colonies of Anacropora forbesi literally covering square meters of the reef in zones where no other corals could be found. Interestingly, it was precisely in the Anacropora habitat that we also observed large patches of thin branching Montipora stellata better in the aquarium hobby as ‘Elkhorn Montipora’.
The thin branches of healthy Anacropora colonies are too closely spaced to create a habitat for small fish to penetrate, or to see the underlying reef bottom and in these places the scenery was that of an attractive lawn of delicate stony coral with fish swimming above it.
The densely growing Anacropora fields we encountered were dominant at a depth of about 15 to 20 feet in clear water where the sun penetrated extremely well. However, Anacropora was also seen on numerous occasions growing at moderate depths up to 60 feet deep, where the light intensity and water movement was greatly reduced.
With Anacropora being such a hardy, fast growing and versatile stony coral, it’s a pity that the genus and more species from it are not more frequently seen in the aquarium hobby. Along with Pocillopora damicornis we consider various species of Anacropora to be a great starter SPS corals whose hardiness and fast growth can be an encouraging first coral for many types of mini reef aquariums.