Macropodus erythropterus

Overview

Macropodus erythropterus is a paradisefish from central Vietnam, sometimes sold under a red-backed label. Red pigmentation helps comparison with similar fish, but its separation from Macropodus spechti has been debated. A trade name alone is not a secure identification.

Distribution & habitat

Confirmed records involve coastal systems in Quảng Bình and Quảng Trị between Đồng Hới and Đông Hà. Occurrence farther south in the Hương and Truồi basins is possible. Collections came from hill streams, particularly complex margins with overhanging vegetation and submerged roots.

Aquarium setup

A pair needs a footprint of at least about 80 × 30 cm. Wood and roots provide shade and retreats; bare-bottom breeding setups are also possible. Include floating or surface plants when breeding is intended. Dried leaves add cover and microorganisms that supplement early fry feeding.

Diet & feeding

Insect larvae and similar small animals are probable wild foods. Offer small live or frozen Daphnia, brine shrimp, white worms, and Grindal worms. Some fish also accept quality dry preparations.

Behaviour & compatibility

Relatively peaceful outside reproduction, it can be kept in pairs or appropriately housed groups. Breeding changes its behavior, so ordinary compatibility should not be assumed throughout the reproductive cycle.

Sexual dimorphism

Males grow larger and develop extended soft rays in the dorsal, anal, and tail fins. Females become paler near spawning.

Breeding

Males build bubble nests. Soft water and a modest temperature increase are reported triggers, within the established suitable range. A close-fitting cover retains warm humid air needed for normal labyrinth development in fry.

Nests are usually supported by surface plants, and females are generally tolerated while construction proceeds. The male displays his extended fins, then spawning embraces occur below the nest. Oil-bearing eggs float upward, sometimes assisted by the male; several hundred may be produced.

Adults can usually remain afterward, and the female sometimes helps defend the nest area. Hatched larvae remain until yolk absorption. Male care declines after free swimming, and adults generally do not eat their young. Begin with microscopic foods such as Paramecium, then introduce microworms and brine shrimp nauplii. Use regular small water changes.

Notes

Useful features include a forked tail, a faint or absent gill-cover spot, and no dark crown or predorsal saddle marks. Dorsal and tail markings are reddish, the back is red-toned, and blue-green iridescence appears above the anal fin. Interpret disputed historical identities with locality information rather than merging records automatically.