When if first started breeding fish, during Ike’s administration one of the first egg laying species that I was fortunate enough to have breed for me was the Medaka Rice fish, Oryzias latipes or Japanese Ricefish. This was a plain light yellow 2 inch fish that was a good community fish. The male would follow the female into the plant thickets and several eggs would hang from the female like grapes. The male would then fertilize them and would swim off. The eggs would hang from the female for a few hours until they would be scraped off on any plants that were in the aquarium. The fish would ignore the eggs , fry could be seen at the surface of the tank in about 10 to 12 days depending upon temperature of the water. The parents took very little interest in the fry if they were well fed. The fry was easy to feed on new hatched brine shrimp for very fine powered foods. I didn’t keep these fish very long , mainly because tank space was short and these were not very pretty fish. Thru the years I was able to obtain several other species of Rice fish, O. melastigmus, O. javanense, O. celebensis and the rarer and larger O. nigrimus. All breed the same and if you were blind in one eye and closed the other you could say all fish in the genus Oryzias were beautiful. Then recently from Sulawesi comes a new species of Ricefish, Oryzias woworae and “wow” are they beautiful.
Sulawesi is a province in Indonesia where this fish is found in still pools and slow moving streams with heavy forest cover. O. woworae is one of the smaller of the species toping out at about 1 1/4 inches. Females have much shorter pectoral fins and dorsal and anal fins than the males and the rear half of the body is edged in a tangerine color extending to the edges of the tail fin. Females have a very pleasing yellow body. Males are a deep neon blue with bright red pectoral fins and the rear of the body is edged in red extending to the edges of the tail fin. The belly is a striking orange. The common name is the Daisy’s Ricefish named after the discoverer Dr. Daisy Wowor an Indonesian crustacean biologist.
I set up a ten gallon tank outside in May with 3 males and 5 females. Plants consisted of a large hunk of Najas grass and water lettuce who’s roots hung down to the bottom of the tank. A small airstone was installed for water movement. Temperature ranged from the low sixties to the mid 80’s. The fish were fed on decapsulated brine shrimp eggs and live daphnia and mosquito larva. Eggs were observed hanging from all the females during the month of May thru July but not a fry was observed. I just happened to be talking to my friend Pete Mang and I mentioned that I wasn’t getting any fry out of my Daisy’s ricefish and was wondering if the drastic temperature shift was affecting fry production. It was then that he told me that he always pulled the spawning medium and hatched the fry seperately from the parents. As soon as I pulled the water lettuce and placed them in a separate tank, in a matter of a few days I had thirty or forty fry. So, the eggs were hatching and the adults were eating the fry soon afterwards. Fry kept hatching a 10 to 14 days after the first were observed.
The fry are fed only decapsulated brine shrimp and Walter worms and grow at a moderate rate. If you were waiting for a colorful Ricefish give these a try.