Nanochromis transvestitus Breeding Guide

Breeding Nanochromis transvestitus, a tiny Lake Mai-Ndombe cave spawner with reversed dichromatism that needs very soft, highly acidic water.

Overview

Nanochromis transvestitus is a tiny dwarf cichlid endemic to Lake Mai-Ndombe (Lake Leopold II) in the middle Congo basin of the Democratic Republic of the Congo, where it lives at around 1 m depth. FishBase records a maximum standard length of just 3.4 cm and lists it as a cave spawner. The lake is exceptionally soft and acidic, and the species is classed as Endangered on the IUCN Red List.

Sexing

This species shows reversed sexual dichromatism: the female is the more colourful sex, with vertical black-and-white banding on the anal and caudal fins and a bright red abdomen, while the male is greyish. Males do, however, have longer anal and caudal fins. The female's bold colours are the clearest sexing cue.

Conditioning

The species feeds on small benthic invertebrates, so conditioning centres on small live and frozen foods. Holding the pair in the very soft, acidic water it requires is essential to bring fish into spawning condition.

Breeding Setup

FishBase lists highly acidic conditions of pH 5.0-6.0 with hardness of 5-12 dH and a temperature of 24-26 C, reflecting the blackwater chemistry of Lake Mai-Ndombe. Provide caves for spawning; the very soft, acidic water is the most demanding aspect of the setup and the reason the species is considered advanced.

Spawning Behavior & Trigger

The fish are cave spawners that, according to Wikipedia, also make a nest in the substrate for the eggs. Pairs exhibit biparental care. Very soft, acidic blackwater conditions are the principal trigger for spawning in this specialised species.

Egg & Fry Care

The species shows the biparental care typical of cave-spawning dwarf cichlids, with the pair guarding the eggs and resulting fry. Detailed egg counts and fry timings are not given in the consulted sources and are therefore omitted.

Common Challenges

Maintaining the very soft, highly acidic water of Lake Mai-Ndombe is the central challenge and the reason this dwarf cichlid is regarded as an advanced subject. Because the species is Endangered in the wild, captive breeding has conservation value, but only stable blackwater chemistry will reliably bring pairs into condition.