Red Bar Anthias (Pseudanthias rubrizonatus)

Anthias harems are matriarchies in practice even though a single male gets top billing — he defends the territory and mates with every female in his group, but the females run a strict size-based pecking order among themselves, and if he disappears, the largest one changes sex within days to take over. The Red Bar's bold color block is a male-phase trait, the reef equivalent of a promotion announcement.

Care level: Moderate · Temperament: Peaceful, shoaling · Max size: ~4" · Min tank: 55 gal · Diet: Carnivore, small meaty foods, frequent feedings