Cardinals frequently are nocturnal by nature and will spend most of their time in the shadier areas of the aquarium and will come out after dark. Their metallic blue, gold, yellow, green and other translucent rainbow colors will make this fish stand out under regular and led home aquarium lighting.
Threadfin Cardinalfish for sale
Cardinalfish are mouthbrooders and for several weeks a male cardinal will not eat while it is carrying babies. Males incubate their eggs inside their mouths, as the egg masses increase in size they can be found with wide-open mouths where they shift the eggs around to aerate the egg masses.