Blue Velvet DamselfishThe Blue Velvet Damselfish , also known as the Japanese Damselfish or the Blue Streak Devil, is black with small blue stripes and one large white vertical stripe. As it matures, it may lose some of its coloring, fading towards brown and black. It will do well in a 30 gallon or larger aquarium. It is aggressive toward other fish and prone to disease if proper aquarium management techniques are not practiced. The Blue Velvet Damselfish feeds on a