Blue Hippo Tang (Dori)

The Blue Hippo Tang (Paracanthurus hepatus) is a large, active Indo‑Pacific surgeonfish known for its bright blue body, black “palette” pattern, and yellow tail. It requires a very large, stable, high‑flow reef system and is best suited for experienced aquarists. 🐠 Identity & Appearance • Scientific name: Paracanthurus hepatus — the only species in its genus • Common names: Blue Tang, Regal Tang, Hippo Tang, Palette Surgeonfish • Coloration: Deep royal blue body, bold black palette pattern, and yellow tail • Adult size: Up to 12 inches (30 cm) in the wild and captivity • Body shape: Laterally compressed, oval surgeonfish with a sharp caudal spine for defense 🌍 Natural Habitat • Range: Widely distributed across the Indo‑Pacific, from East Africa to Japan, Indonesia, Micronesia, and the Great Barrier Reef • Environment: • Outer reef slopes, channels, and lagoons • Depths 2–40 m with strong currents and branching Acropora for shelter • Behavior in the wild: • Juveniles school in large groups • Adults travel in loose shoals and retreat into coral heads at night 🧠 Behavior & Temperament • Temperament: Semi‑aggressive; establishes hierarchy through brief chases • Activity level: Extremely active, constant swimmer • Defense: Uses a sharp caudal spine; may “play dead” or lighten color when stressed (inferred from related sources) • Reef‑safe: Yes — herbivorous grazer that does not harm corals 🏡 Aquarium Requirements This species is not suitable for small tanks. • Minimum tank size: • 125 gallons recommended by multiple care guides • 180 gallons strongly recommended for long‑term welfare due to adult size and swimming needs • Tank length: At least 6 feet for proper swimming room • Aquascape: • Open swimming lanes • Branching rock or coral structures for shelter • Water parameters: • 75–82°F, pH 8.1–8.4, salinity 1.023–1.025, dKH 8–12 • Flow: Moderate to strong, high oxygenation 🍽️ Diet • Type: Primarily herbivore (with some omnivory) • Wild diet: Filamentous algae, benthic films, and small planktonic organisms • Captive diet: • Nori • Spirulina‑based pellets • Herbivore blends • Occasional mysis or enriched brine 🧬 Lifespan & Health • Lifespan: 20–30 years in captivity; up to 30 years in the wild • Common issues: • Highly prone to marine ich and velvet due to thin slime coat • Stress from small tanks or poor water quality • Quarantine: Strongly recommended 🪸 Compatibility • Good tankmates: Peaceful to moderately assertive reef fish • Use caution with: Other tangs, especially similar body shapes • Best practice: Add last to reduce territorial behavior