Coryphopterus personatus (Masked Goby)
• Small fish safe: ✅ Yes
• Small invert safe: ✅ Yes
• Coral safe: ✅ Yes
• Minimum tank size: 40L+ (preferably 75L+ for groups)
• Adult size: ~4 cm (1.6 inches)
• Diet: Carnivorous (marine pellets, frozen mysis/brine shrimp, finely chopped seafood)
• Be aware of: Highly peaceful and best kept in small groups. Prefers shaded or cave-like areas within the reef structure. May be overlooked in large aquariums due to its small size.
Masked Goby (Coryphopterus personatus) – A Tiny and Peaceful Reef Dweller
The Masked Goby is a small, schooling fish commonly found in Caribbean and Atlantic reef environments. Known for its semi-transparent body and striking red or orange markings, this species is a great choice for nano reefs and peaceful community tanks. Though it may not be as bold as some larger gobies, its calm demeanor and schooling behavior make it a fascinating species to observe.
Appearance and Coloration
The Masked Goby is delicate in appearance, featuring:
• A mostly translucent body, allowing it to blend into reef structures.
• A dark “mask” across the face, giving it its common name.
• Rows of white dashes along the spine, alternating with orange or red blotches.
• Large, expressive eyes, characteristic of gobies that rely on quick movements to avoid predators.
Its subtle yet intricate markings make it a visually interesting but understated addition to a reef tank.
Natural Habitat and Behaviour
Native to the Western Atlantic, including Florida, the Bahamas, and throughout the Caribbean, Masked Gobies are found in coral-rich reef zones, where they:
• Hover in small schools, typically above caves or rocky overhangs.
• Prefer shaded environments, avoiding bright, exposed areas.
• Exhibit sequential hermaphroditism, meaning they can change sex depending on social structure.
• Are peaceful and non-aggressive, making them excellent community fish.
In captivity, they retain their natural schooling and hovering behaviors, making them ideal for nano reef setups.
Tank Requirements and Water Parameters
Due to their tiny size and peaceful nature, Masked Gobies require a stable, well-established reef tank.
• Minimum tank size: 40L+ (75L+ recommended for groups)
• Temperature: 24–27°C (75–81°F)
• pH: 8.1–8.4
• Salinity: 1.020–1.025
• Water movement: Moderate (gentle flow preferred)
• Filtration: Good-quality filtration and regular water changes to maintain water clarity.
Providing plenty of caves, overhangs, and shaded areas will help them feel secure.
Diet and Feeding
Masked Gobies are micro-predators, feeding on small zooplankton and microorganisms in the wild. In captivity, they require a fine, varied diet to stay healthy.
Recommended foods include:
• Frozen mysis and brine shrimp – Their primary diet in captivity.
• High-quality marine pellets and flakes – Small sinking formulas work best.
• Finely chopped seafood (shrimp, squid, or fish) – Occasional treats.
• Live foods (copepods, amphipods, or blackworms) – Encourages natural feeding behavior.
Feed once or twice daily, ensuring food particles are small enough for them to consume easily.
Compatibility and Tank Mates
Masked Gobies are highly peaceful and thrive best in small groups, making them great for:
✔ Other small, peaceful fish, such as Firefish, Clownfish, and Basslets.
✔ Reef-safe invertebrates, including shrimp, snails, and crabs.
✔ SPS and LPS coral tanks, as they do not nip at coral or disturb rockwork.
Avoid housing with:
❌ Large, predatory fish (e.g., Lionfish, aggressive Dottybacks, large Wrasses) that may eat them.
❌ Very aggressive fish, as they are easily intimidated.
❌ Fast-swimming or food-aggressive species, as Masked Gobies are slow feeders.
If keeping a group, introduce them at the same time to allow them to establish a natural hierarchy.
Behavior and Schooling in the Aquarium
Masked Gobies tend to hover near rockwork or cave structures, where they:
• Swim in coordinated small groups, creating a natural schooling effect.
• Rarely venture far from their hiding spots, preferring to stay near cover.
• Do best in dimly lit areas, making them ideal for aquariums with indirect lighting.
⚠ Their small size means they may be overlooked in large aquariums, so nano or small reef tanks are best for visibility.
Health and Disease Considerations
Masked Gobies are generally hardy, but due to their small size, they can be vulnerable to:
• Marine Ich (Cryptocaryon irritans) – Often caused by stress or poor water conditions.
• Malnutrition – Ensure they receive small, frequent feedings, as they cannot compete with larger tank mates.
• Stress from aggressive tank mates – Best kept in peaceful community setups.
To maintain their health:
✔ Provide a varied diet rich in small zooplankton substitutes.
✔ Ensure stable water parameters with low nitrates.
✔ Quarantine new fish before adding them to the main tank.
Lifespan and Long-Term Care
With proper care, Masked Gobies can live up to 3-5 years in captivity. Their calm schooling nature, reef-safe behavior, and easy maintenance make them a great choice for peaceful aquariums.
Why Choose a Masked Goby?
✔ One of the smallest gobies, perfect for nano reef tanks.
✔ Forms peaceful schooling groups, making them fun to watch.
✔ Completely reef-safe, with no risk to corals or invertebrates.
✔ Easy to care for, making them great for beginners and experts alike.
✔ Blends well into natural reef setups, adding a sense of realism.
⚠ Important Considerations Before Buying a Masked Goby:
🚫 Needs small, peaceful tank mates – Cannot compete with large or aggressive fish.
🚫 Requires multiple feedings – Small stomachs mean they need frequent, fine-sized food.
🚫 Best kept in groups – More active and comfortable when schooling.