Paradise Fish (Macropodus opercularis) Breeding Guide

Breeding the paradise fish: bubble-nest building, soft warm water trigger, the osphronemid embrace, several hundred floating eggs, male nest care and infusoria-grade first foods.

Overview

Macropodus opercularis is a labyrinth fish reaching about 70-80 mm and is a bubble nester. It tolerates a wide range of conditions, roughly 10-22 °C, pH 6.0-8.0. Males are territorially aggressive, and this behaviour becomes more pronounced during reproductive periods.

Sexing

Males are larger than females and possess extended soft rays in the dorsal, anal and caudal fins.

Conditioning

Condition the prospective pair well before introduction. Soft water with a slightly raised temperature is said to induce reproductive behaviour, so warming the spawning tank a little supports the trigger.

Breeding Setup

Provide a raft of surface vegetation in which the male can build his nest. The male constructs the nest among floating plants, and the female is usually tolerated in the area during this period.

Spawning Behavior & Trigger

Once the nest is complete the male displays to potential mates using his elongated dorsal, anal and caudal fins, and the nuptial female becomes paler in colour. Spawning normally occurs beneath the nest in the embrace typical of osphronemids, with the male wrapped around the female. At the point of climax milt and a few eggs are released; the eggs contain a globule of oil and are lighter than water, so they float upwards to the nest, often assisted by the male. Several hundred eggs are typically deposited.

Egg & Fry Care

Eggs hatch in 3-4 days and the fry remain in the nest until yolk absorption is complete. When the fry begin to swim freely the male will lose interest, and the adults are best removed at this stage. Fry require an infusoria-grade food for the first few days, after which they can accept motile foods such as microworm and Artemia nauplii.

Common Challenges

The main difficulty is male aggression, which intensifies during breeding and can endanger the female once spawning is complete, so the female should be removed after eggs are laid. As a labyrinth fish, fry also need access to a layer of warm humid air at the surface for proper development of the labyrinth organ.