Taxonomy & naming
Parenti and Hadiaty described the species in 2010 from a spring called Fotuna near the village of Wakumoro on Muna Island, off southeast Sulawesi. The name honours Daisy Wowor, an Indonesian carcinologist at the national research institute in Cibinong, and the common name Daisy's ricefish comes from the same dedication. It belongs to the Sulawesi radiation of Oryzias.
Morphology
A small, slender ricefish; FishBase gives a maximum of 1 in SL. Males show orange to yellow on the body and fins, with extended dorsal and anal fin tips in good condition, while females are paler and more translucent. The eyes are large and the mouth upturned, as in Oryzias generally.
Habitat
Spring-fed streams and pools on Muna Island, a limestone island in southeast Sulawesi. FishBase describes a freshwater fish with a pH of 6.0 to 7.0; it gives no temperature range. The only known collection came from the type locality, the spring called Fotuna at Wakumoro, so the range is extremely limited.
Feeding
A surface and mid-water feeder that takes small crustaceans, insect larvae and algae. In captivity it accepts baby brine shrimp, microworms, daphnia, crushed flakes and fine pellets.
Mating
Males display to the female with the fins spread, circling and following her. Spawning takes place over plants or a spawning mop during the day.
Breeding
As in most Oryzias, the female carries a small cluster of eggs on threads at her vent for a time and then brushes it off on fine plant material. Spawning mops of yarn or Java moss collect the eggs well. The fry are tiny and need infusoria or very fine foods in the first days, then baby brine shrimp. Adults eat the eggs, so move them or the adults.
In the aquarium
One of the most rewarding of the Sulawesi ricefishes. Keep a group of six or more in a planted tank with a lid. FishBase gives a pH of 6.0 to 7.0 and no temperature range. Use fine live and frozen foods for good colour. Tank-bred fish from hobby breeders are widely available, which means there is no reason to depend on wild collection. Keep it with other small, peaceful fish or shrimp.
Conservation
The IUCN Red List classes Oryzias woworae as Endangered, meaning it faces a very high risk of extinction in the wild. The species is known from a single spring on one small island, so it is vulnerable to spring and land-use change. Widespread aquarium culture provides an insurance population, though captive stocks are no substitute for the wild habitat.