Geophagus proximus Breeding Guide
Breeding Geophagus proximus, a hardy Amazon eartheater that is an ovophilous biparental mouthbrooder with broods of around 200 eggs.
Overview
Geophagus proximus is an adaptable eartheater from the Amazon River system in Peru and Brazil, recorded from the Rio Ucayali to the Rio Trombetas near Santarem. According to Seriously Fish it is a substrate-spawning, ovophilous, biparental mouthbrooder that has been bred in aquaria, often traded under the name surinamensis.
Sexing
Accurate sexing is difficult in juveniles. Mature males are slightly larger with longer fins, and dominant males may develop a nuchal hump; the female shows a visible ovipositor when spawning. Raising a group and letting pairs form is the reliable route.
Conditioning
There is no specific spawning trigger. A good diet and a stringent maintenance regime with relatively large weekly water changes are the primary requirements to bring adults into condition.
Breeding Setup
- Soft sandy substrate with a flat rock or driftwood spawning site; a tank base of at least 180 × 60 cm
- Temperature: 24-29 °C (KB record range)
- pH: 5.5-7.5 (KB record range)
- Hardness: 2-12 °dGH (KB record range)
- Large weekly water changes
Spawning Behavior & Trigger
Courtship involves fin flaring, circling, gaping and head-jerking displays. The pair selects a flat rock, driftwood or the tank base, cleans and defends it, then spawns in typical substrate-spawning fashion with repeated cycles over several hours. No specific trigger is identified.
Egg & Fry Care
Maximum brood size is around 200 eggs. Females typically hold the eggs initially while males defend the territory, though brooding may be shared simultaneously or exchanged daily. Fry become free-swimming at 8-11 days at 25-28 °C; once free-swimming the parents gradually release them for longer feeding periods and the fry return to the mouth when threatened.
Common Challenges
Because the trade name often masks the true species, confirming identity helps set correct expectations. The fish needs a large footprint and soft sand; in community tanks the brood is vulnerable, so protecting fry or isolating the brooding pair improves yield.