Add an ethereal glow to your planted aquarium with the stunning Celebes Rainbowfish (Marosatherina ladigesi). Known for their semi-translucent, shimmering neon-yellow and ice-blue bodies and the elongated, thread-like fin rays of mature males, these peaceful schooling fish are a mesmerizing centerpiece for community tanks.

Overview & Place of Origin

The Celebes Rainbow, also widely known as the Celebes Rainbowfish (Marosatherina ladigesi, formerly Telmatherina ladigesi), is an exquisite freshwater fish native to the island of Sulawesi (formerly Celebes), Indonesia. In the wild, they inhabit slow- to moderate-flowing, crystal-clear streams and rivers flowing through limestone foothills, where the water is naturally clean, mineral-rich, and slightly hard.

Quick Aquarium Care Stats:

Scientific Name: Marosatherina ladigesi
Common Names: Celebes Rainbowfish, Celebes Rainbow, Celebes Sailfish
Care Level: Intermediate
Temperament: Peaceful, active, schooling
Adult Size: Approx. 2.5 to 3 inches (6–7.5 cm)
Minimum Tank Size: 20 to 30 gallons
Diet: Omnivore / Micropredator
Water Temperature: 72°F – 82°F (22°C – 28°C)
pH Range: 7.0 – 8.0 (Prefers neutral to moderately alkaline)
Hardness: 10 – 20 dGH (Prefers medium-hard water)

Aquarium Environment & Care

To bring out their most vibrant coloration and graceful display behaviors, Celebes Rainbowfish require a well-established setup with pristine water quality:

Tank Size & Swimming Space: A minimum tank size of 20 to 30 gallons (preferably a long aquarium, 30+ inches in length) is recommended. These are fast, open-water swimmers that need ample horizontal room to dart and display.
Aquascaping: Create a natural layout featuring dense background planting (such as Vallisneria, Cryptocoryne, and stem plants) combined with driftwood or river stones, leaving an open swimming zone across the middle and upper levels.
Water Flow & Quality: They thrive with gentle to moderate water flow and efficient biological filtration. Celebes Rainbowfish are sensitive to sudden water parameter swings and elevated nitrates; regular partial water changes are essential.
Substrate & Lighting: Dark substrate and subdued lighting (or shaded areas created by floating plants) will make their iridescent neon blues and sunny yellows truly pop.

Feeding & Diet

Celebes Rainbowfish are enthusiastic omnivores and surface-to-midwater feeders with relatively small mouths:

Provide a core diet of high-quality crushed micro-pellets and color-enhancing flake food.
Supplement regularly with live or frozen foods such as baby brine shrimp (Artemia), daphnia, cyclops, and finely chopped bloodworms.
Feeding vitamin-rich live or frozen prey is crucial for conditioning males to develop their signature extended dorsal and anal fin rays.

Ideal Tank Mates

Celebes Rainbowfish are gentle, non-aggressive fish that must be kept in schools of at least 6 to 8 individuals (a mix of 2 males to 4–6 females is ideal). A proper school prevents shyness and prompts males to flare their dramatic fins in harmless sparring rituals.

Great Companions: Peaceful community species such as dwarf shrimp (adults), small rasboras, neon/cardinal tetras, peaceful dwarf cichlids (like Apistogramma or Mikrogeophagus), Corydoras catfish, Otocinclus, and small livebearers (guppies, platies, endler’s).
Species to Avoid: Aggressive fin-nippers (e.g., tiger barbs), large predatory fish, or overly boisterous species that may outcompete them for food or stress them out.

Breeding Celebes Rainbowfish

Breeding Celebes Rainbowfish in the home aquarium is rewarding for hobbyists:

Sexual Dimorphism: Males are significantly more colorful, displaying vibrant yellow tints with extended black and yellow filaments on their dorsal and anal fins; females are smaller, plainer, and slightly rounder.
Spawning Setup: Set up a dedicated breeding tank with slightly warm water (77°F–80°F) and fine-leaved live plants (like Java Moss) or a clean spawning mop.
The Process: Condition the breeders with live foods. The male will court the female in the morning light. Celebes are egg-scatterers that lay sticky eggs over several days. Because adults will readily eat their own eggs, remove the parents or swap the spawning mop daily into a separate hatching container. Fry hatch in 7 to 10 days and can be raised on infusoria, micro-worms, and freshly hatched baby brine shrimp.

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The photos shown on fish product pages are representations of adult fish and are NOT the actual fish that you will be receiving.
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