Blue Hippo Tang - Paracanthurus hepatus

The Blue Hippo Tang (Paracanthurus hepatus), also called the Regal Tang or “Dory” fish, is a standout reef-safe surgeonfish prized for its electric blue body, bold black patterning, and constant, active swimming. Like most tangs, it’s a dedicated grazer that helps manage nuisance algae when given ample space, high water quality, and a steady supply of marine-based greens.

• Scientific Name: Paracanthurus hepatus
• Max Size: Up to 12 inches
• Diet: Primarily herbivore (marine algae/seaweed) with meaty foods offered occasionally
• Tank Size: 125+ gallons (180+ recommended for adults)
• Temperament: Semi-aggressive (generally peaceful; may be territorial with other tangs)

Best kept in a mature, well-oxygenated aquarium with strong filtration, brisk water movement, and open swimming lanes. Provide rockwork and caves for shelter—Blue Hippo Tangs often wedge themselves into crevices to rest, especially when newly introduced.

• Reef Safe: Yes (does not nip corals or invertebrates)
• Activity Level: High—needs long stretches of open water to cruise
• Compatibility: Usually peaceful with most community reef fish; use caution mixing with other tangs, especially similar-shaped species
• Care Level: Moderate—space, diet, and stability are key

Diet & Feeding Tips

To support long-term health and coloration, feed a varied menu focused on marine plant matter. Offer seaweed daily and rotate quality prepared foods to reduce nutritional gaps.

• Nori/seaweed sheets (daily)
• Spirulina-based flakes or pellets
• Frozen herbivore blends
• Occasional meaty options (e.g., mysis) for variety—not as the main diet

Habitat & Water Conditions

Blue Hippo Tangs are sensitive to rapid changes and do best with stable reef parameters and consistent maintenance. Quarantine is strongly recommended, as tangs are commonly susceptible to external parasites in stressful transitions.

• Temperature: 74–80°F
• pH: 8.1–8.4
• Alkalinity: 8–12 dKH
• Specific Gravity: 1.020–1.025
• Setup: Strong flow, high oxygenation, ample swimming room, and multiple hiding spots

Temperament & Stocking Notes

In a properly sized tank, the Blue Hippo Tang is a great centerpiece fish for reef communities. Introduce with care if adding other tangs—larger aquariums, plenty of rockwork, and adding tangs in a planned order can help reduce territorial behavior.

• Good tankmates: Clownfish, wrasses, gobies, many angelfish (species-dependent), other peaceful reef fish
• Avoid/Use caution: Small tanks, overcrowded systems, and mixing with similarly sized tangs in limited space

FAQ

• Will a Blue Hippo Tang eat algae? Yes—this species grazes on algae and benefits from daily seaweed feedings, though it won’t replace good nutrient control and maintenance.
• Can I keep a Blue Hippo Tang in a 75-gallon tank? It may be temporarily housed when small, but long-term success is best in 125+ gallons (larger is better) due to its adult size and constant swimming.
• Is the Blue Hippo Tang reef safe with corals? Generally yes—it’s considered reef safe and typically ignores corals and most invertebrates when well-fed.