Red Phantom Tetra Breeding Guide

Breeding Hyphessobrycon sweglesi: sexing by fins, conditioning, a dim egg-trap spawning tank, soft acidic water and raising the light-sensitive eggs and fry.

Overview

Hyphessobrycon sweglesi is a characin from the Orinoco River basin that breeds as an egg-scattering free spawner exhibiting no parental care. In a mature, well-planted aquarium small numbers of fry may start to appear without intervention, but a dedicated setup greatly increases the yield.

Sexing

Adult males develop extended dorsal and anal fins, while females are deeper-bodied. Mature, conditioned females also become noticeably rounder when full of eggs.

Conditioning

Condition the broodstock, kept in a group of at least 8-10 specimens, on small live and frozen foods such as bloodworm, mosquito larvae, Daphnia and Moina. Well-fed fish spawn readily.

Breeding Setup

Use a separate, dimly lit tank filled with water from the main aquarium. Fit a mesh barrier that lets eggs fall through but keeps the adults away from them; plastic grass matting, glass marbles, or fine-leaved plants such as Taxiphyllum or spawning mops serve the same purpose. An air-powered sponge filter or air stone provides gentle oxygenation and water movement.

Spawning Behavior & Trigger

Breeding water should be slightly acidic to neutral, against the species' general range of pH 4.5-7.5, with temperature toward the upper end of the 20-28 °C range. Dim lighting and these soft, warm conditions trigger spawning, after which the scattered eggs fall through the barrier out of reach of the parents.

Egg & Fry Care

The eggs and newly hatched fry are light-sensitive, so the tank should be kept shaded. First foods are Paramecium or a proprietary dry fry food of 5-50 micron grade, advancing to Artemia nauplii and microworms as the fry grow.