The Japanese Swallowtail Angel, Genicanthus melanospilus, also known as the Spotbreast or Blackspot Angel, is a unique angelfish species native to the coastal waters of Japan. What makes the Japanese Swallowtail unique is its stark differentiation between male and females. Most angelfish don't exhibit much sexual dimorphism, but the Swallowtail Angel is an exception.
Males feature a silver/white body with black vertical striping across its body up to is head. Blue caudal fins sometimes accentuate it with a splash of color.
Female individuals feature a snow white body with a bright yellow back and dorsal fin. Males and females are easily distinguished and in many cases look like completely different species altogether.
Japanese Swallowtail Angelfish are best kept:
in tanks of at least 130 gallons with plenty of live rock hiding places
away from fleshy corals, sessile inverts, or clam mantles that may become an easy snack
when fed a varied omnivorous diet of algae, spirulina, and meaty frozen foods
and only as individuals. Swallowtail's should not be kept together unless in a very large tank in which case a pair of females, a mated pair, or a group of females with one male can be kept