Acropora millepora is one of the most iconic and recognizable SPS corals on the reef and in the aquarium trade. However, within shipments of Australian Acro Millis we’ve secretly been receiving a lurker species endemic to Australian reefs, Acropora spathulata. Like the classic Acro Milli, A. spathulata has characterisitc scalloped radial corallites which join together to almost look like chain mail. What makes A. spathulata stand out is that it has much thicker branches than Acro milli, especially at the base, and the scalloped radial corallites are even more pronounced. A few weeks ago we were speaking with Kevin Kohen of LiveAquaria and discussing our observations about these apparently unique Aussie millis and that’s when he brought to our attention A. spathulata, a species which is not recognized by Charles Veron in Corals of the World but it is by other leading corals taxonomist.
Most notably, In Staghorn Corals of the World Carden Wallace explains at length that A. spathulata has significant differences in morphology, genetics and the clincher is reproductive isolation of the species because it spawns at a slightly different time than A. millepora. So far most of the A. spathulata colonies we’ve seen resemble the color pattern of the inset image to the right but hopefully we’ll see some colonies like the one in the header image once the collectors realize that A. spathulata and A. millepora are different animals.