Gold Tetra (Hemigrammus rodwayi) Breeding Guide
How to breed Hemigrammus rodwayi: an egg-scattering characin spawned in soft acidic water over fine plants, with light-sensitive eggs that hatch in 24-36 hours.
Overview
Hemigrammus rodwayi is an egg-scattering characin from lowland South America, recorded from Guyana, Suriname, French Guiana, Peru and Brazil, where it is abundant in coastal floodplains. The golden sheen of wild fish is attributed to a reaction to internal trematode parasites; aquarium-bred specimens lack this tint and appear silvery. As with most small Hemigrammus, the species provides no parental care, so eggs and fry must be protected from the adults.
Sexing
Females are fuller and more rounded in the belly, especially when carrying eggs. Males show a white leading edge on the anal fin and carry more red pigmentation than females.
Conditioning
Condition the breeding group on plenty of small live and frozen foods until females are visibly rounded with eggs. Fish may be conditioned in a group of around six of each sex or as separately fattened males and females selected for pairing.
Breeding Setup
- Spawning tank around 18 x 10 x 10 inches, kept very dimly lit.
- Soft, acidic water: pH 5.5-6.5 and hardness around 1-5 gH; peat filtration and reverse-osmosis water help.
- Temperature approximately 27-29 C (80-84 F).
- Clumps of fine-leaved plants such as java moss or spawning mops, or a mesh base that lets eggs fall out of reach of the adults.
- A gently bubbling air-powered sponge filter.
Spawning Behavior & Trigger
Pairs or small groups scatter non-guarded eggs among fine-leaved plants or through a protective mesh. Soft, acidic water and subdued light act as the main spawning triggers. The adults will eat the eggs given the chance and should be removed as soon as spawning is complete.
Egg & Fry Care
Eggs hatch in 24-36 hours, and the fry become free-swimming about 3-4 days later. The eggs and fry are light sensitive in the early stages, so the tank should be kept in darkness as far as possible. Start the free-swimming fry on infusoria-type foods, moving on to microworm and brine shrimp nauplii as they grow.