Nanochromis parilus Breeding Guide

Breeding the blue Congo dwarf cichlid Nanochromis parilus, a soft-water cave spawner that will not spawn above pH 6.5, with biparental fry care.

Overview

Nanochromis parilus is a slim Congo dwarf cichlid from the lower Congo River rapids in the Democratic Republic of the Congo. Seriously Fish gives adult males to about 8 cm and females to about 7 cm, and FishBase records a maximum standard length of 4.4 cm with a diet of worms, crustaceans and insects. It is a bi-parental cave spawner that requires soft, acidic water.

Sexing

Females are more colourful than males, showing a violet flush to the belly, while adult males are larger overall. The female's intensified belly colour is the clearest sexing and conditioning cue when she is ready to spawn.

Conditioning

The species accepts most foods but live and frozen varieties should predominate, matching its natural diet of worms, crustaceans and insects. A well-conditioned pair held in soft acidic water is the basis for a successful spawn.

Breeding Setup

Provide very soft water at pH 5.0-6.5 and a temperature of about 25-27 C (77-80 F); the species will not spawn above pH 6.5. The pair excavates a cave beneath a rock or piece of driftwood, so supply rockwork or wood under which a spawning cavity can be dug.

Spawning Behavior & Trigger

Spawning is bi-parental and takes place in the excavated cave, where the female lays rows of eggs on the ceiling while the male fertilises them. Sufficiently soft, acidic water below pH 6.5 is the key trigger, as the species will not spawn in harder or more alkaline conditions.

Egg & Fry Care

The female generally takes the main responsibility for the eggs while the male defends the spawning site, with some role swapping; the male joins fully in care once the fry are free-swimming. Eggs hatch in 2-3 days and fry become free-swimming around 7-10 days after spawning. The relatively large fry can take microworm and brine shrimp nauplii from the moment they are free-swimming, with brood care lasting about a month.

Common Challenges

Achieving soft, acidic water below pH 6.5 is essential, since spawning will not occur otherwise. The species is aggressive toward conspecifics and is best kept as a single pair, and the guarding pair should be given space and cover during brood care.