Court Jester Goby (Koumansetta rainfordi)

The Court Jester Goby, also known as the Rainford Goby, is a peaceful and beautifully patterned fish that adds color and charm to any marine aquarium. Known for its distinctive green and blue stripes along its body and yellow-orange accents, this goby is an ideal addition to reef tanks, where it will actively sift sand and graze on algae. Its peaceful nature makes it suitable for a wide variety of community tanks, though it requires a stable, well-established environment with a healthy sand bed and abundant algae.

Care Information

• Maximum Size: Up to 2.5 inches.
• Tank Size: 20 gallons minimum; a tank with live rock and a mature sand bed is ideal for providing natural foraging areas.
• Diet: Omnivorous; primarily grazes on filamentous algae and detritus within the sand bed. In captivity, it can be fed small meaty foods like mysis shrimp and brine shrimp, as well as algae-based foods to supplement its grazing habits.
• Water Temp: 72-78°F.
• Salinity: 1.020-1.025.
• Aggression: Peaceful; the Court Jester Goby is a non-aggressive species and does well in community and reef tanks with other peaceful fish. It is best kept singly or in pairs unless the tank is large enough to support multiple individuals.
• Skill Level: Intermediate; due to its specialized diet and need for a mature tank, the Court Jester Goby requires a stable, well-maintained environment to thrive.
• Reef Compatibility: Reef-safe; does not harm corals or invertebrates and is beneficial for helping to control algae and aerate the sand bed through its sifting behavior.

Special Feature - Algae Grazing and Sand Sifting
The Court Jester Goby is known for its beneficial role in reef tanks, where it grazes on algae and sifts through the sand in search of food. This behavior helps control algae growth and aerates the substrate, which supports a healthy tank environment. Providing a mature tank with abundant algae and microfauna is essential for this fish's long-term health.

Compatibility
This goby is a peaceful species that can coexist with a wide variety of tankmates, including other small, non-aggressive fish and invertebrates. It may, however, compete with other algae grazers, so a stable environment with adequate algae or supplemental feeding is essential.

Coloration

• Western Pacific Region: The Court Jester Goby displays a striking combination of green and blue horizontal stripes along its body, accented by yellow-orange spots on the head and fins. Its vibrant yet subtle colors make it a beautiful addition to any tank​.

Typical Habitat

• Distribution: Native to the Western Pacific, particularly around the reefs of Australia, the Court Jester Goby is found in sandy and rubble areas of coral reefs. It prefers environments with plenty of hiding spots and a healthy sand bed where it can sift for food.