Geophagus winemilleri Breeding Guide

How to breed Geophagus winemilleri, a Rio Negro eartheater; a substrate-spawning, larvophilous biparental mouthbrooder that takes hatched larvae into the mouth.

Overview

Geophagus winemilleri is an eartheater of southern Venezuela and probably northern Brazil, with confirmed collections from the upper Rio Negro, Rio Siapa and the Casiquiare system, according to Seriously Fish. It is described as a substrate-spawning, larvophilous, biparental mouthbrooder that has been bred in aquaria, reaching about 180-200 mm. It is best kept in a group.

Sexing

According to Seriously Fish, the sexes appear identical except when spawning, at which point the ovipositor of the female is visible. As with related eartheaters, raising a group of juveniles allows pairs to form naturally.

Conditioning

An omnivorous sand-sifter, the species is conditioned on a varied diet. A group in a spacious, sandy tank with stable, warm, soft water promotes pair formation; once a pair bonds it will select and clean a spawning site.

Breeding Setup

Provide a flat rock or piece of driftwood over sand as the spawning surface. Seriously Fish reports breeding-suitable conditions of 26-30 C and pH 4.0-7.0, in line with the soft, acidic blackwater of the Rio Negro region.

Spawning Behavior & Trigger

Seriously Fish describes courtship involving fin flaring, circling, gaping and head-jerking. The pair cleans a spawning site, and the female lays one or more rows of eggs before the male fertilises them, repeated over several hours. Warm, soft water and a settled pair are the practical triggers.

Egg & Fry Care

Being larvophilous, the parents leave the eggs on the substrate until they hatch. Seriously Fish reports that after about 72 hours the fry are taken into the mouth of the female, though both parents may be involved from the start. Once free-swimming, care is shared, and parental contribution varies between individual males.

Common Challenges

Because the sexes are identical outside spawning, group rearing is the only reliable way to obtain a pair. Maintaining soft, warm water and providing enough space for the holding parent are the main practical considerations.