Red-back Paradise Fish Breeding Guide

How to breed Macropodus erythropterus, a Vietnamese paradise fish that is a bubble-nesting anabantoid; the male builds a surface nest and tends the floating eggs.

Overview

Macropodus erythropterus is a paradise fish endemic to central Vietnam, where Wikipedia records it from the Quang Tri River basin in hill streams with submerged roots and overhanging vegetation. It grows to about 70-80 mm standard length according to Seriously Fish and is a bubble-nesting labyrinth fish.

Sexing

Seriously Fish states that males are larger than females and possess extended soft rays in the dorsal, anal and caudal fins. These differences become most apparent as fish reach breeding condition.

Conditioning

Adults are conditioned on a varied diet before spawning. Seriously Fish notes that soft water with a slightly raised temperature is said to induce reproductive behaviour. A base of at least 80 x 30 cm is recommended for the species.

Breeding Setup

The species tolerates a broad range, with Seriously Fish listing 20-30 C, pH 6.0-8.0 and hardness 90-357 ppm. A well-planted tank with floating cover gives the male a site to build his surface bubble nest.

Spawning Behavior & Trigger

The male constructs his nest within surface vegetation. According to Seriously Fish, spawning normally occurs beneath the nest in an embrace typical of osphronemids, with the male wrapped around the female; several hundred eggs are usually deposited. The oil-rich eggs float upward to the nest, often with the male's assistance.

Egg & Fry Care

Post-spawning the adults can normally be left in situ; the female is usually tolerated by the male and may help defend the area around the nest. The eggs remain in the nest until the yolk sac is absorbed. Seriously Fish advises feeding an infusoria-grade food for the first few days, after which the fry accept motile foods such as microworm and Artemia nauplii, with small regular water changes.

Common Challenges

As a semi-aggressive paradise fish, the male can harass a female that is not ready, so cover and conditioning are important. Maintaining stable conditions and ample surface plants supports nest stability and fry survival.