Breeding Medaka Rice Fish

Breeding Medaka Rice Fish

Medaka rice fish, also known as Japanese rice fish or Oryzias latipes, are small freshwater fish that are native to Japan and Korea. They are a popular choice for home aquariums due to their small size, hardiness, and peaceful nature. Medaka rice fish typically reach a maximum size of about 2 inches and can live for 2-3 years. They have a silvery-white body color with a transparent dorsal fin and a dark spot on their tail fin. They are also known for their unique breeding behavior, which includes the male carrying eggs in his mouth for protection. Medaka rice fish are also used in scientific research as a model organism for genetic and developmental studies. They are hardy and easy to breed and can be maintained in laboratory conditions.


To breed them obtain a breeding pair of medaka rice fish. These fish are small and easy to care for, making them a popular choice for home aquariums.

Set up a breeding tank for the medaka rice fish. The tank should be at least 40L in size and have a water temperature between 72 and 78 degrees Fahrenheit.

Add a breeding mop or other type of spawning material to the tank. This will provide a place for the female fish to lay her eggs.

Feed the breeding pair a balanced diet of live or frozen food such as brine shrimp, bloodworms, or daphnia.

Monitor the breeding pair for signs of spawning. The male fish will often display courtship behavior, such as chasing the female and displaying his fins. The female will also become plumper as she fills with eggs.

Once spawning has occurred, remove the breeding pair from the tank to prevent them from eating the eggs.

Keep the breeding tank at the optimal temperature and pH levels, and provide plenty of oxygen to the eggs by using an air stone or a filter.

After about 3-4 days, the eggs will hatch into fry. At this point, you can start feeding them small amounts of infusoria or newly hatched brine shrimp.

As the fry grow, you can gradually increase the size and variety of their food.

Keep a close eye on the tank's water quality and make sure to perform regular water changes to prevent the buildup of waste and harmful bacteria.

As the fry grow, you can start to separate them into different tanks or sell them to other aquarium enthusiasts.