Diadema Pseudochromis

The Diadema Pseudochromis (Pseudochromis diadema), also known as the Flash Back Dottyback or Diadem Dottyback, is one of the most eye-catching small reef fish in the saltwater hobby. Brilliant lemon-yellow body topped with a bold magenta-purple stripe running from the head down the back — a two-tone color combination that's impossible to ignore, even from across the room.

Pseudochromis (dottybacks) are hardy, active, and surprisingly bold for their small size. The Diadema constantly darts in and out of rockwork hunting for small prey, swimming with confident, jerky movements that show off the color contrast. They're disease-resistant, easy to feed, and acclimate quickly to captive life — making them an excellent choice for both new and experienced reefers.

Temperament note: Like most dottybacks, Diademas can be territorial and semi-aggressive, especially in smaller tanks or with similar-shaped fish. They're known to harass new additions and may bully smaller, more peaceful tankmates. Best added last to an established system, or housed with semi-aggressive tankmates that can hold their own.

Completely reef-safe with corals and most inverts, though they may hunt very small ornamental shrimp like sexy shrimp.

At Ocean To You, every fish is quarantined and observed before sale. We don't sell sick fish.