The Centropyge pygmy angelfish make up the largest genus of marine angelfishes and their diversity and abundance has led to many different variants being discovered by the aquarium hobby. Among these oddball pygmies there exists a whole spectrum of poorly studied yellow Centropyge with varying degrees of black markings, usually around the dorsal and anal fins and we’ve long ascribed these morphs to one species or another.
But at long last we finally have some insight into one of these varieties, the double black fin angelfish from Fiji which finally received some scientific attention through genetic analysis of a couple specimens. Our armchair taxonomy long believed that the double black fin angelfish was a variety of the common yellow angelfish, Centropyge heraldi, but genetic analysis has not supported this assumption, and instead has found a closer relationship with the bicolor angelfish, Centropyge bicolor.
While the title of the research paper by Kang & Chih calls the double black fin angelfish a ‘variant’ of C. bicolor, the more detailed conclusion within the paper elaborates that it “should be essentially a color variant of C. bicolor from Fiji or might be simply an undescribed species within the C. bicolor species complex, and this assumption needs to be clarified if more specimens can be obtained“.
The study only examined two samples of the double black fin from Fiji but we’ve seen many more examples of this fish from the Philippines so it would be interesting to learn if those fish share the genetic markers of the bicolor angelfish. We still have the darker ‘panda angelfish’ to consider as a variant or undescribed species in further research and who knows, it might share some similar evolutionary history as the double black fin angelfish. [Ichthyological Research]