Chrysiptera cyanea is a species of damselfish found in the wide Indo-West Pacific but not known in the Red Sea.[2] A few individuals were observed in the Mediterranean Sea in 2013 off Slovenia, a likely aquarium release.[3]
Common names include blue damselfish, blue demoiselle, blue devil, cornflower sergeant-major, Hedley's damselfish, red tail Australian damsel, sapphire devil, and sky-blue damsel.[4]
This fish reaches 8.5 centimeters in length. It is bright blue in color; the male has a yellow snout and tail, and the female and juvenile usually lack yellow but have a black spot at the base of the back edge of the dorsal fin.[2][5]
Behavior
The fish inhabits reefs and lagoons. Its diet includes algae, tunicates, and copepods. Male and female pair up for breeding, and the male guards and tends the eggs.[2]
In aquarium
It is very aggressive. A matched couple often attacks any same size fish approaching its breeding territory.[5]
