Evers' Medaka

Oryzias eversi is a ricefish from central Sulawesi named in honour of Heiko Bleher and Uwe Werner's collecting partner. Males in spawning condition develop bright yellow-orange dorsal and anal fin colouration that contrasts with the silver body. It is one of a group of closely related Sulawesi Oryzias requiring the same warm, hard, alkaline water conditions as its congeners.

In the aquarium, O. eversi is a lively, peaceful schooling fish that does well in groups of eight or more. It is important to maintain the warm, hard, alkaline parameters typical of Sulawesian waters. Standard tropical community water is usually too soft and acidic, leading to gradual decline.

Breeding follows the typical Oryzias pattern and is not difficult once appropriate water conditions are established. Eggs develop quickly at higher temperatures and fry are free-swimming and large enough to accept micro nauplii from day one.

Water: 25-30°C, pH 7.5-8.5, hard (GH 10-20) — maintain Sulawesi lake chemistry. Tank: 30 L, open swimming space with some fine-leaved plants; strong lighting. Feeding: micro granules, baby brine shrimp, daphnia, and vinegar eels for conditioning. Breeding: egg scatterer; easy once water parameters are correct; eggs deposited on fine vegetation. Compatibility: peaceful with other Sulawesi species; safe with small invertebrates.