Gymnogeophagus rhabdotus Breeding Guide
How to breed the striped eartheater Gymnogeophagus rhabdotus, a biparental substrate-spawner reported as one of the easier members of the genus to spawn.
Overview
Gymnogeophagus rhabdotus is a striped subtropical eartheater from Rio Grande do Sul in southern Brazil and the Uruguay River drainage. Unlike the mouthbrooding members of the genus, it is a biparental substrate-spawner and is reported as easily bred in captivity — easier than the mouthbrooders. It prefers a fine-sand bottom with hiding places.
Sexing
It is best kept and bred in pairs. As elsewhere in the genus, males tend to grow larger; given subtle dimorphism, growing out a group to allow natural pairing is the practical route to forming a compatible pair.
Conditioning
A varied diet within a stable aquarium conditions adults. The genus benefits from seasonal cooling, and this species is among the easier to bring into breeding condition once a pair has formed.
Breeding Setup
- Reported spawning temperatures around 20-25 °C, with the preferred spawning range near 23-25 °C.
- pH around 7-7.5 and hardness around 16-20 in the reviewed source.
- A fine-sand bottom with rocks, caves and driftwood for hiding places.
- A tank of adequate length (about 1.5 m suggested) to support a territorial breeding pair.
Spawning Behavior & Trigger
As a substrate-spawner, the female lays eggs on a flat surface or in a small pit, reported at up to around 300 eggs, which the male fertilises while defending the breeding territory. Both parents then participate in care.
Egg & Fry Care
Eggs hatch after about two days and the fry are moved to a brooding pit, where both parents guard them. Juveniles become free-swimming after roughly five days and can be raised on newly hatched brine shrimp (Artemia nauplii) and powdered food.
Common Challenges
The record lists this species as a mouthbrooder, but the sources reviewed describe it as a biparental substrate-spawner; this guide follows the sources. Historically the genus's reproductive modes have been debated, and rhabdotus is now treated as a substrate-spawner. Providing space for a territorial pair is the main practical consideration.