Celestial killifish
Aphyosemion coeleste
This killifish reaches about 4–5 cm. Males display an intense electric blue with red spots on the flanks and caudal fin. Females are duller, brownish with a few spots. It is a peaceful species but males can be territorial with each other. In the aquarium, it prefers soft, acidic water with dense vegetation and subdued lighting. It reproduces by laying eggs on a substrate (Java moss or peat fibers). The eggs require a drying period to hatch (incubation 3–6 weeks).
Recommended parameters
| Parameter | Recommended range |
|---|---|
| Temperature | 22–26 |
| pH | 6–6.8 |
| GH | 2–6 |
| KH | 1–3 |
| NO₃ | ≤ 20 |
| PO₄ | ≤ 0.5 |
Care
Care notes
Keep soft water (GH 2–6, KH 1–3) and acidic (pH 6.0–6.8) at a temperature of 22–26°C. A minimum tank volume of 30 liters is recommended for a pair. Feed a varied diet: brine shrimp, daphnia, bloodworms, and small pellets. Avoid strong currents. Use gentle filtration (sponge or foam). Floating plants and hiding spots are appreciated. Sensitive to nitrates (max 20 mg/L). Regular water changes (20% weekly). Compatible with other small peaceful fish (rasboras, small corydoras).