The Chinese Ricefish is a tiny freshwater fish, up to about 1.2 in (3.1 cm) long, that lives in rice paddies and marshes of East and Southeast Asia; it isn't known from the wild in the US. It looks almost exactly like the Japanese Ricefish (medaka) and was once treated as part of that species, so it is still often called by that name.
Appearance
- Appearance
- Up to about 1.2 in (3.1 cm) long, slender and rather see-through. Unlike the Japanese Ricefish, it has no spots along its sides, and its belly and anal fins are blackish rather than yellowish.
Look-alikes
Japanese RicefishOryzias latipes
The Japanese Ricefish has many small spots on its sides, and its belly and anal fins are yellowish. A sure ID needs vertebra and counts, so photos are often not enough.
Why they get mixed upThe two are nearly identical and were once considered one species.
Where it lives
- Typical habitats
- Rice paddies
- Marshes
- Ponds
- Slow streams
- Irrigation channels
- Range
- Native to China (including the Yangtze, Mekong, and Red River basins) and parts of Southeast Asia, and also found in western Korea. It has been introduced to southern Russia, Kazakhstan, and Ukraine. The USGS database of nonnative US fish lists only the Japanese Ricefish in this genus, not this species.
- Preferred conditions
- Prefers shallow, slow-moving water with plenty of plants. It goes dormant when the water turns cold.
Behavior
- Diet
- An omnivore that eats tiny zooplankton, algae, plant bits, and insect parts.
Life cycle
- Lifespan
- Usually about a year in the wild, but four years or more in captivity.
Name and classification
- About the name
- First described in 1989 as a of the Japanese Ricefish (Oryzias latipes sinensis) and now treated as its own species. It has 46 chromosomes versus 48 in the Japanese Ricefish, and genetic studies support the split.
Conservation
- IUCN Red List
- LCLeast ConcernLow risk of extinction
- Threats
- Where it has been introduced, it is rated a high risk of becoming invasive. Its small size helps it settle into new waters.
Culture and stories
- Culture and stories
- Because it is easy to raise, with short generations and clear eggs, it is also used as a research fish.
More species to explore
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