Macropodus

Macropodus erythropterus is a paradisefish from coastal hill streams of central Vietnam, in Quang Binh and Quang Tri provinces. Occasionally traded, sometimes as 'red-backed paradisefish', it is often misidentified as M. spechti, which lacks red in the dorsal, anal and caudal fins. Whether the two represent the same taxon has been debated. A bubble nester, it is relatively peaceful unless breeding.

Macropodus hongkongensis is a paradisefish from Hong Kong and the neighbouring Chinese provinces of Guangdong and Fujian. In Hong Kong it is now known only from Tai Po and Sai Kung districts. It lives in hill streams and lowland, sometimes agricultural, habitats, apparently preferring shallow, densely vegetated water with slow flow. Males are territorially aggressive, especially when breeding, and the species is a bubble nester that is occasionally available in the trade.

The roundtail paradise fish, Macropodus ocellatus, is a labyrinth fish with an enormous range in China, Korea and Japan, north to the Amur River. It lives in ditches, rice paddies, marshes and river backwaters, where winter can freeze the surface and drop the water to 3 °C. It is sometimes referred to as M. chinensis in older literature, a name now considered a synonym of M. opercularis. Males are territorial when breeding and build bubble nests.

The paradise fish, Macropodus opercularis, is a labyrinth fish from China south of the Yangtze, including Taiwan and Hainan, plus Vietnam and Laos. Imported to France in 1869, it was among the very first ornamental fish brought to Europe. Wild examples are uncommon in the hobby since it is farmed extensively, and xanthic, albino, red, blue and stripeless strains exist. Males are territorially aggressive, especially when breeding, and should not be housed together unless the aquarium is very large.

The black paradise fish, Macropodus spechti, is a labyrinth fish from central Vietnam, known with certainty from the Thu Bồn and Hương river systems. Its name is frequently misapplied to the similar-looking M. erythropterus, easily identified by reddish pigmentation in the dorsal, anal and caudal fins. Older literature sometimes refers to it as M. concolor. Relatively peaceful unless breeding, it is kept in pairs.