The Ruby Anthias is one of the larger anthias species. This is the only downside though, because it is a beautiful active fish! It's not imported on a regular basis, so if you have the space and you see it somewhere, it's worth buying them. This is not really a schooling Anthias. It's usually observed in small aggregations over the reef, so a small group of 4-6 fish will do well in a large tank. When buying a group you don't need to worry about sex ratios because these fish are hermaphroditic. This means the most dominant fish will automatically turn into the male when there is no other male around.
Due to their size they are best in an aquarium with larger fish species such as Angelfish and Butterflyfish. They may eat smaller invertebrate species but will not harm coral.
Do make sure they can eat multiple times a day though, because in nature they feed on zooplankton the entire day, and are not build for one meal a day!
Juveniles are yellowish with a few dark spots.