The Semicirculatus Angel, often referred to as the Blue Koran Angel, is a beautiful juvenile phase fish, which is very similar in markings to that of the Juvinile Emperor Angel. The Semicirculatus is a dark blue with narrow white and blue semicircular bands running along its body, becoming more arched towards the rear. The pattern will begin to dissolve into that of the adult at approximately 4 inches. These fish do fairly well in aquariums and prefer lots of rockwork to feel comfortable. The Semicirculatus Angel should be kept in a tank of 90 gallons or larger, so it'll have ample room to roam. They will spend most of their day grazing algae that grows on live rock. They should not be kept with other Angels and only one should be kept per tank.