Genicanthus melanospilus With a highly-flared tail, the Swallowtail Angelfish is also referred to as the Blackspot Angelfish, Blackspot Lyretail Angelfish, and Spotbreast Angelfish. The Blackspot Angelfish is one of the few angelfish to exhibit dramatic sexual dimorphism. The female is yellow dorsally, and light blue ventrally. The caudal fin is marine-blue highlighted by a dark, blue-black edging on the top and bottom. The male is a pale yellow, with multiple thin, dark, vertical stripes. A minimum of a 100-gallon tank or larger with lots of hiding places and live rock for grazing will offer an environment in which to thrive. An exception to most angelfish, the Blackspot Angelfish will make a good reef dweller, and will not nip at stony and soft corals (sessile invertebrates). It is also more peaceful and may be kept as a mated pair, or in schools. The diet of the Blackspot Angelfish should include Spirulina, marine algae, high-quality angelfish preparations, and finely chopped mysid or frozen shrimp