Rainfordi Court Jestor Goby - Amblygobius rainfordi

Rainford’s Court Jester Goby (Amblygobius rainfordi)

The Rainford’s Court Jester Goby, Amblygobius rainfordi, is a small, peaceful marine goby with a slender body, colourful horizontal striping and a delicate grazing habit. Also known as Rainford’s Goby, Court Jester Goby or Old Glory Goby, this attractive species is highly desirable for mature reef aquariums where it can browse naturally over live rock, sand and algae films. It is reef safe and gentle, but it is not a fish for sterile new systems, as it does best in established aquariums with natural microfauna, fine foods and calm tank mates.

Common Name:
Rainford’s Court Jester Goby, Rainford’s Goby, Court Jester Goby, Old Glory Goby, Rainfordi Goby.

Scientific Name (Latin):
Koumansetta rainfordi
Still widely traded as Amblygobius rainfordi.

Maximum Size:
Usually around 5–6 cm.

Water Type:
Marine

Origin / Natural Habitat:
Western Pacific, including reef habitats around Australia and surrounding tropical regions. In the wild, Rainford’s Gobies occur on sandy and muddy bottoms, coastal coral reefs, rubble zones and reef flats, often where algae growth and fine natural foods are available for grazing.

Water Parameters:
Temperature: 24–27°C
pH Range: 8.1–8.4
Hardness or Salinity: Marine salinity 1.023–1.026 specific gravity; stable, mature marine conditions with good oxygenation are recommended.

Temperament:
Peaceful and shy. This species is best kept with calm reef fish that will not bully it or outcompete it for food. It is not aggressive, but may be intimidated by boisterous wrasses, dottybacks, damsels or large active fish.

Diet:
Omnivorous micro-grazer. In the aquarium, offer finely chopped frozen foods, enriched brineshrimp, cyclops, copepods, fish eggs, small mysis, fine marine pellets, algae-based foods and specialist micro-grazer diets. A mature aquarium with live rock, sand, natural film algae and copepod life is strongly recommended, as newly imported specimens may be slow to accept prepared foods.

Minimum Tank Size:
A minimum of 90 litres is recommended for a single specimen, with larger aquariums preferred for mixed reef communities. Stability and natural grazing opportunities are more important than simply keeping the fish in the smallest possible tank.

Behaviour & Activity:
A bottom-associated goby that spends much of its time hovering close to the sand, perching on rockwork and picking at algae films, sand surfaces and tiny food particles. It may gently sift small amounts of sand, but it is not a heavy-duty sand-cleaning goby. It is usually most confident in a peaceful, mature aquarium with hiding places and established rockwork.

Reef Safe:
Reef Safe
Safe with corals and most ornamental invertebrates. It may consume tiny copepods, micro-crustaceans and planktonic foods as part of its natural feeding, but it is not a coral picker and is generally suitable for peaceful reef aquariums.

Special Requirements or Care Notes:
Best kept in a mature reef aquarium with live rock, fine sand, natural algae films and stable water quality. Avoid brand-new or ultra-sterile systems where there is little grazing available. Feed small, frequent meals and monitor body condition carefully, as this species can become thin if it does not receive enough suitable food. A secure lid is recommended, as gobies can jump when startled. Choose peaceful tank mates and avoid aggressive feeders during acclimation.

Suitable for:
Intermediate marine fishkeepers

Availability:
Occasional in trade / Specialist marine import

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.