Bali Shortcake Acropora. 3/4-1″ Mother Colony Picture Shown.Acropora Corals in general include a wide variety of different species of Acropora corals with many different color and growth forms. Acropora corals found within the aquarium hobby (including Purple Acropora Corals) are available in a variety of growth forms that are according to size and shape of the branches, the position of the branches, the number of corallite septa and the nature of the coenosteum. The most commonly available aquarium species tend to fall into the following growth forms: branching, bushy, cluster, finger, bottlebrush and tabular, with bushy being by far the most commonly available within the hobby. Prices for Acropora Corals also vary widely based on the size, growth form and coloration of a specific specimen, with lighter purple colored bushy corals representing the least expensive and finger, branching and tabular specimens with a dark purple coloration making up the high end of the market. Purple Acropora Corals are available within the aquarium hobby, but are considered semi-rare which typically brings a higher price tag and limited availability.