Picasso Triggerfish (Rhinecanthus aculeatus)
• Small fish safe: ❌ No (may eat smaller fish)
• Small invert safe: ❌ No (will prey on crustaceans and mollusks)
• Coral safe: ❌ No (may nip at corals and rearrange rockwork)
• Minimum tank size: 265 liters (70 gallons) for juveniles, 375+ liters (100+ gallons) for adults
• Adult size: Up to 30 cm (12 inches)
• Diet: Carnivorous, feeding on crustaceans, mollusks, and small fish
• Be aware of: Can be aggressive, may bite if provoked, will eat invertebrates, requires space and secure rockwork
Appearance and Coloration
The Picasso Triggerfish is named for its striking geometric patterns and vivid colors, resembling the abstract artwork of Pablo Picasso. Its body is a mix of tan, white, blue, and black markings, with bright yellow accents around the mouth and eyes. A characteristic blue stripe runs across the forehead, while bold black bands extend along the flanks.
Natural Habitat and Behavior
Native to the Indo-Pacific region, Rhinecanthus aculeatus is found in shallow coral reefs, lagoons, and rocky coastal waters, typically at depths of 1 to 50 meters (3 to 165 feet). It prefers areas with plenty of hiding spots among rocks and corals.
Picasso Triggerfish are highly territorial and will defend their space aggressively, especially as they grow older. They are also known to be intelligent and curious, often recognizing their owners and reacting to external stimuli. In the wild, they rearrange rocks and shells to create shelter, a behavior they will exhibit in captivity as well.
Tank Requirements and Water Parameters
• Minimum Tank Size: 70 gallons (265 liters) for juveniles, 100+ gallons (375+ liters) for adults
• Water Parameters:
• Temperature: 24°C – 28°C (75°F – 82°F)
• pH: 8.1 – 8.4
• Specific Gravity: 1.020 – 1.025
• Aquascaping:
• Provide caves, ledges, and secure rock structures for shelter.
• Avoid fragile rockwork, as triggers may rearrange their environment.
• A large swimming area is necessary, as they are active swimmers.
• Lighting: Moderate to bright reef lighting is acceptable.
• Water Movement: Moderate to strong, mimicking their natural reef conditions.
Diet and Feeding
Picasso Triggerfish are carnivorous predators with powerful jaws adapted for crushing hard-shelled invertebrates.
• Natural Diet: Crustaceans, mollusks, sea urchins, and small fish.
• Captive Diet:
• Chopped shrimp, squid, clams, and krill.
• High-quality frozen marine foods.
• Hard-shelled foods (such as mussels or snails) to wear down their continuously growing teeth.
• Pellets and flakes formulated for carnivorous marine fish.
Feeding Frequency: 2-3 times per day for juveniles; once or twice daily for adults.
Compatibility and Social Structure
• Temperament:
• Aggressive and highly territorial, especially as they mature.
• Will often bully smaller or more passive tank mates.
• Tank Mates:
• Best kept with larger, semi-aggressive fish such as groupers, tangs, larger wrasses, puffers, and other triggerfish.
• Avoid housing with small fish, shrimp, crabs, or other invertebrates, as they will be eaten.
• Not suitable for peaceful reef tanks due to their destructive tendencies.
• Reef Compatibility: ❌ Not reef-safe—they will eat small invertebrates and may nip at corals.
Important Considerations
• Territorial and Aggressive: Becomes more aggressive with age; ensure tank mates can hold their own.
• Rearranges Rocks: Secure aquascaping is essential, as they will move objects in the tank.
• Bites if Provoked: Picasso Triggers have strong jaws and can bite hands or equipment if they feel threatened.
• Teeth Growth: Requires hard-shelled food to naturally wear down their continuously growing teeth.
• Tank Size Increases with Age: Needs a 100+ gallon tank once fully grown.