Daisy's Rice Fish

Daisy's Rice Fish (Oryzias woworae) is a dazzling miniature ricefish endemic to a single karst stream system on the island of Muna in Southeast Sulawesi, Indonesia. Measuring just 2.5–3 cm in standard length, it is the smallest Oryzias species known from Sulawesi and one of the most vibrantly colored, with an iridescent blue body accented by brilliant orange-red margins on the caudal fin, anal fin, and ventral caudal peduncle. During courtship, dominant males intensify their coloration dramatically, sometimes appearing nearly black with deep indigo tones, making them a striking centerpiece in any small-scale aquascape.

Despite their tiny stature, these fish are active and confident when kept in groups of eight or more. They are peaceful by nature, but their diminutive size makes them unsuitable for standard community tanks — they are best housed with other small, non-predatory species such as Microdevario, Sundadanio, Trigonostigma, pygmy Corydoras, Otocinclus, or freshwater shrimp of the Caridina and Neocaridina genera. Males engage in harmless sparring during courtship but are not aggressive toward tankmates outside of breeding periods. They are unfussy eaters, accepting crushed high-quality dry foods, Artemia nauplii, microworms, and similar small live or frozen offerings, and will also graze aufwuchs from solid surfaces.

Daisy's Rice Fish adapt readily to a well-maintained aquarium of 40 liters or more with stable water conditions. They are not demanding in terms of decor but display best in a naturalistic setup with a sandy substrate, water-worn roots, and leaf litter — or a densely planted aquascape. Recommended water parameters include a temperature of 23–27°C, pH 6.0–7.5, and hardness up to 268 ppm. Breeding is straightforward and prolific: females produce 10–20 adhesive eggs every few days, which hang from the genital pore before being deposited among fine-leaved plants or spawning mops. Incubation takes 1–3 weeks depending on temperature. While adults do not actively hunt eggs, they will predate free-swimming fry, so separating eggs or providing dense cover improves juvenile survival. Keep fry of markedly different sizes apart, as larger juveniles may eat smaller ones.