Banggai Cardinalfish (Pterapogon kauderni). PIN CHANGED TO LINK TO ARTICLE ABOUT BREEDING THIS SPECIES. Link is to an update article on the original article about breeding this species, which is linked in the article as well.
As most photographers know, one of the best ways to locate a creature hidden among weeds, corals, rocks, etc is to look for the regular pattern of its eyes. Being round, symmetrical, and quite often black, it is easy to look for them among the background. This is exactly what predators have learned to look for . So some fish have evolved a number of ways to avoid detection, and confuse. Many have a black band crossing the eye .