Hikari Danio

A small danio showing pronounced sex-linked colour differences, with cooler blue tones in males and warmer gold tones in females.

Its contrasting male and female colour forms are among the most useful features for recognising mature fish.

Danio dichromatus was formally described in 2024. Older trade material may have been sold simply as Hikari Danio or Danio sp. Hikari.

Sexual dimorphism is conspicuous in mature fish. Males tend to show cooler blue or steel tones and a slimmer outline, while females are usually fuller-bodied and display warmer gold or yellow colour.

Aquarium information for this uncommon species is limited, so conservative husbandry and careful observation are advised. Keep a group of at least 8 in an aquarium at least 80 cm long.

Provide open swimming space, secure cover, efficient filtration, and moderate water movement. Use plants, wood, and rounded stone around the margins while preserving a clear central swimming area.

Keep planting and hardscape around the margins so the school has cover without losing the open midwater space it uses most.

Hikari Danio is a social, active schooling fish that should be maintained with its own kind. Most chasing is part of normal group interaction, but cramped quarters or a group that is too small can concentrate aggression.

Maintain at least 8, preferably 12 or more. A larger group produces more natural schooling and spreads chasing. Not truly territorial, although males may spar or defend short-lived display positions within the group.

Choose peaceful, similarly active fish that share the same temperature and water requirements. Very slow, timid, or long-finned tankmates may be stressed by constant movement or persistent feeding competition. Small shrimp and shrimplets may be eaten.

Keep the water clean and oxygen-rich. Soft to moderately hard water is preferable, with no sudden chemistry changes.

A small, peaceful danio. Offer fine flake and micro pellets with frozen daphnia or brine shrimp.

Feed small portions once or twice daily. Active danios feed quickly, so check that slower tankmates receive food.

An egg-scattering spawner with no parental care. Condition adults well, then use fine-leaved plants, spawning mops, mesh, or marbles to protect eggs from the adults. Remove the breeders after spawning and raise the fry on infusoria or very fine prepared food before moving to microworms and Artemia nauplii. For uncommon species, keep detailed notes on temperature, timing, adult condition, and fry growth because dependable species-specific aquarium reports may be limited.