The only species in this group is a morphologically, ecologically and biogeographically distinct species that has traditionally been included alongside the perideraion group in the subgenus Phalerebus. The two are very obviously sister groups, as indicated by their similarly reduced pectoral fin ray count and the heavily scaled predorsal region, but, importantly, this species differs in growing larger (up to 13.5 cm), having a thicker white dorsal stripe that extends onto the upper lip, and in having yellow (vs. clear) fins.
But the most important distinction between these two, and the one which has most directly allowed for their sympatric speciation in the Coral Triangle, is the shift in host preference, with A. sandaracinos relying almost entirely on Stichodactyla mertensii (vs. Heteractis magnifica in the perideraion group). Interestingly, genetic data has thus far failed to support this very obvious relationship, placing A. sandaracinos as the sister species to the Polynesian A. pacificus. This should be presumed to be an erroneous result, as all other available evidence argues against this relationship. Clearly, more study is needed.