The round-tailed paradise fish (Macropodus ocellatus) is a species of gourami native to eastern Asia, where it is found in China, Japan, and Korea. It is also known to occur in the Amur Basin of Russia, but that is believed to be due to introductions. It inhabits many kinds of freshwater habitats within its range. This species is reported to be well adapted to cold weather during winter in its relatively northern range, even to the point of remaining active when their body of water is covered with ice. This species grows to a length of 6.2 cm (2.4 in), and can be found in the aquarium trade.