They eat very well, I think..

Ghost Cardinalfish (Zoramia leptacantha) , also called the Blue-Eyed Cardinalfish, is a peaceful shoaling species ideal for Reef aquariums. Growing to about 6–7 cm, it should be kept in groups of at least 5–7 individuals, where its natural schooling behavior creates a beautiful, shimmering display. This Hardy species is reef-safe, easy to feed with frozen or dry foods, and best suited to tanks with plenty of live rock and peaceful tankmates.