Pygmy Hatchetfish Breeding Guide

Breeding the pygmy hatchetfish (Carnegiella myersi): the smallest, most delicate hatchetfish, with no recorded captive spawning; covers the limited sexing clue and soft-water needs.

Overview

The pygmy hatchetfish, Carnegiella myersi, is the smallest and most delicate of the nominal hatchetfishes, reaching only about 20-25 mm. Its aquarium reproduction is not recorded; like its relatives it is an egg-scattering surface fish, but no verified captive-breeding account exists.

Sexing

Sexual differences are poorly defined. The only guidance is that females are presumably rounder, especially when viewed from above; there are no dependable colour or fin distinctions.

Breeding Setup

Without a proven method, conditions should mirror the species' soft, acidic origins and surface habits, providing floating cover and very gentle water movement. Reported maintenance parameters are a temperature of 23-26 degrees C, pH 4.0-7.0 and hardness 18-108 ppm.

Common Challenges

The decisive difficulty is the complete absence of documented spawning, leaving no protocol to follow. The fish is very peaceful but small and timid, must be kept in a group of at least six and ideally more, and is an insectivore that takes small floating foods; its delicacy makes both conditioning and any fry-rearing attempt demanding. Until reliable reports appear, breeding remains experimental.