The Pink Square Anthias, Pseudoanthias pleurotaenia, is hermaphroditic meaning all are born females, and when needed the dominant female turns into male. They also display sexual dimorphism with the male featuring a general red/orange body with a bright pink square and highlights of blue, purple and yellow on the fins and tail while the female displays a solid yellow/orange color. They can be kept as a mated pair, or in a small school of females. Avoid keeping two males in the same tank, as it can lead to extreme aggression.
They are hardy and can be kept in a reef tank setting with plenty of live rock. Diet should include a variety of a steady supply of copepods, frozen mysis and vitamin enriched brine shrimp, as well as high quality flake foods 3-5 times daily.
I ordered 3 of these beautiful fish when they were on sale. One was doa, sadly, but the other 2 were in great shape. Both were eating frozen and pellets within hours of acclimation. They seem happy in their 20g quarantine tank. Hopefully they stay healthy in the display tank in a month. I highly recommend this fish, especially at saltwaterfish.com prices.