Royal Dottyback

Royal Dottyback: The Feisty Bicolor Gem

The Royal Dottyback (Pictichromis paccagnellae) is one of the most popular and hardy fish in the marine aquarium trade, highly prized for its striking and distinct coloration. It is also commonly mistaken for the Bicolor Dottyback or False Gramma Dottyback because of its visual similarity to the much more peaceful Royal Gramma (Grammaloreto), a fish often confused with this species.

This fish is instantly recognizable, featuring a bold two-toned pattern: the front half of its body is a vivid purple or magenta, which sharply divides mid-body to a bright sunny yellow that covers the posterior and tail. This small but feisty fish reaches a maximum size of only about 3 inches (7.5 cm) in length, making it suitable for smaller marine systems.

Native to the Western Pacific, the Royal Dottyback is often recommended for beginner aquarists due to its hardiness and readiness to eat. However, its small size belies a highly territorial and aggressive personality, requiring careful tankmate selection to ensure a peaceful community.

Diet & Compatibility:

• Diet: The Royal Dottyback is a natural Carnivore and a micropredator, feeding on small worms and crustaceans in the wild. It readily accepts a wide variety of prepared meaty aquarium foods, including frozen mysis shrimp, enriched brine shrimp, finely chopped marine fish and shrimp flesh, and high-quality carnivore pellets. Feeding once daily is usually sufficient.
• Reef Compatibility: It is Reef Safe With Caution. The fish will not harm corals, but it may prey on small ornamental invertebrates like small cleaner shrimp (e.g., sexy shrimp) and smaller crustaceans. A beneficial trait is its known appetite for nuisance bristleworms, which it actively hunts and consumes.
• Temperament: It is Semi-Aggressive / Highly Territorial. Despite its small size, the Royal Dottyback is notorious for defending its chosen territory (usually a cave or crevice in the live rock) against any perceived intruder, even fish several times its size. For this reason, it should be the last fish introduced to a community tank, and it must be kept singly unless the aquarium is very large (100+ gallons) and has multiple distinct territories.
• Tankmates: Suitable tankmates are usually larger, robust, and moderately aggressive fish that are not easily intimidated, such as larger tangs, clownfish, or some hawkfish. Avoid keeping it with slow-moving or peaceful fish like most gobies and Firefish, which it may harass or prevent from feeding. It must also be kept away from similar-looking fish, such as the Royal Gramma ( Grammaloreto ), as it will relentlessly attack them.
• Housing: Due to its secretive nature, the aquarium must have plenty of live rock arranged to create numerous caves and crevices for shelter. Like many dottybacks, it is a known jumper, so a tight-fitting lid is essential.

Quick Facts

• Scientific Name: Pictichromis paccagnellae
• Primary Common Name: Royal Dottyback
• Origin: Western Pacific Ocean (Indonesia to Vanuatu)
• Max Size: 3 inches (7.5 cm)
• Temperament: Semi-Aggressive / Highly Territorial
• Diet: Carnivore (Meaty foods, including bristleworms)
• Minimum Tank Size: 30 Gallons
• Reef Compatibility: With Caution (May eat small ornamental shrimp)