Emperor Tetra Breeding Guide

How to breed Nematobrycon palmeri: sexing by eye colour and tail shape, conditioning, and rearing the fry from eggs that are released only a few at a time.

Overview

Nematobrycon palmeri is a characid from the Atrato and San Juan river basins in western Colombia. It is an egg scatterer with no parental care; in a large, well-planted aquarium a single pair will often breed without extra stimulation.

Sexing

The most reliable difference is eye colour: males have metallic blue eyes, females metallic green. Males are larger with longer anal fins and a three-pronged tail whose central black stripe extends beyond the rest of the fin, while in females the median stripe usually reaches only as far as the clear part of the tail.

Conditioning

Condition the fish with plenty of small live foods, selecting a female noticeably full of eggs and a male in his best colour.

Breeding Setup

Use a very dimly lit tank of about 16 x 8 x 8 inches with water at pH 6.0-7.0, gH 1-10 and around 75-80 °F (24-27 °C). Provide clumps of fine-leaved plants such as java moss or spawning mops, or a mesh base through which eggs can fall, plus a gently bubbling air-powered sponge filter. The species is best spawned in pairs.

Spawning Behavior & Trigger

Transfer the selected pair in the evening; they typically spawn the following morning. Only a few eggs are released at a time, so the event can continue for several hours.

Egg & Fry Care

The adults eat the eggs and should be removed as soon as eggs are noticed. Eggs hatch in 24-36 hours and the fry become free-swimming 4-5 days later. Offer infusoria for the first week, then microworm or brine shrimp nauplii.