Occasionally one or maybe more of the species of normally black surgeonfish develops a variably blotchy yellow and black (and sometimes white) color as adult. Possibly these species are yellow as juveniles, and do not completely change to their adult dark color. Even after examining our photos, I'm not certain which of the normally black tangs these represent. What is probably our most common dark-colored species, Ctenochaetus striatus, is not yellow as a juvenile, so it would seem to not be that one. Right now we just call them Calico tangs.
This one may be a calico form of another species.
Created 8 July 2017