Rainford’s Goby (Koumansetta rainfordi)

The Rainford’s Goby, also known as the Old Glory Goby, is one of the most decorative and functional small fish in the marine hobby. While the Engineer Goby we discussed previously is a "heavy-duty excavator," the Rainford’s Goby is a "precision detailer." It is a peaceful, sand-sifting species that is famous for its intricate, almost "tribal" markings and its helpful habit of consuming nuisance film algae.

Key Information

• Common Names: Rainford's Goby, Old Glory Goby, Court Jester Goby

• Scientific Name: Koumansetta rainfordi

• Origin: Western Pacific (Philippines to the Great Barrier Reef)

• Max Size: 6–8 cm (approx. 2.5–3 inches)

• Lifespan: 2–4 years

• Temperament: Very Peaceful; shy and unobtrusive

• Diet: Omnivore – Sand sifter and algae grazer

• Care Level: Moderate (due to specific feeding needs)

Appearance & Identification

The Rainford’s Goby looks like it was hand-painted with high-contrast pinstripes:

• The Pattern: A greenish-grey body decorated with horizontal orange-to-red stripes that run from the nose to the tail.

• The "Eyes": It features several black ocelli (eye-spots) along its dorsal fin, designed to confuse predators into thinking it’s a much larger fish.

• The Size: It remains very slender and small, making it a perfect inhabitant for nano-reefs.

Behaviour: The "Gentle Sifter"

• Sand Sifting: Unlike the Diamond Watchman Goby (which can create sandstorms), the Rainford's Goby sifts sand very delicately. It takes a small mouthful, filters out the micro-crustaceans, and "spits" it back out right where it was, keeping your sand bed clean without burying your corals.

• Algae Control: It is one of the few gobies that will actively graze on filamentous algae and hair algae growing on the rocks.

• Reef Safe: 100% Reef Safe. They are absolute gentlemen in a reef environment and will never bother a coral or an invertebrate.

• Shyness: They are not "bold" swimmers. They prefer to stay near the bottom or close to rock crevices where they can retreat if they feel threatened.

Ideal Tank Setup

• Tank Size: A minimum of 40L–75L (10–20 Gallons). They are excellent candidates for "desktop" nano-reefs.

• Substrate (Mandatory): You must have a fine-to-medium sand bed. They rely on sifting the sand for a portion of their nutrition.

• Rockwork: Provide plenty of "nooks" and "crannies." They like to have a familiar territory to patrol.

• Feeding: This is the challenge. Because they are constant grazers, they can starve in brand-new, sterile tanks. They need a mature tank with natural micro-fauna. Supplement their diet with small frozen foods like Cyclops or Vitamin-enriched brine shrimp.