Aulonocranus dewindti Breeding Guide

How to breed the featherfin Aulonocranus dewindti: sand-bower colony courtship, maternal mouthbrooding, conditioning the group and rearing the fry.

Overview

Aulonocranus dewindti is a sand-dwelling featherfin endemic to Lake Tanganyika. It is a maternal mouthbrooder in which territorial males build large sand structures and gather in breeding colonies, attracting females that hover above the substrate. Spawning is recorded to recur roughly every eight to ten weeks per female under good conditions.

Sexing

Males grow larger and more colourful than females and develop extended fins; dominant individuals turn an iridescent blue. Females remain plainer. As with related featherfins, the most reliable cue at maturity is the male's intensified colour and his nest-building activity.

Conditioning

Keep the fish in a group with several females per male and feed generously to bring them into condition. Aquarist breeding accounts describe feeding the colony baby brine shrimp, white worms and crushed flake; with such feeding multiple females will hold young at any given time while others recover from a previous spawn.

Breeding Setup

A spacious tank with a deep sand bed is essential, as the dominant male excavates a very large nest. In one documented colony of three males and nine females in a 90-gallon tank, a dominant male dug a structure that took up roughly a third of the tank, around 18-20 cm (7-8 in) deep, within the first week. Water was maintained near pH 8.2 and 24-27 C.

Spawning Behavior & Trigger

Territorial males form breeding colonies and attract females from the groups hovering above the sand. Spawning takes place over the male's nest; the female collects the eggs into her mouth and they are fertilised at the nest before she withdraws to brood. Generous feeding and stable warm, hard, alkaline water sustain the recurring spawning cycle.

Egg & Fry Care

Females hold the brood for about one to two weeks. Aquarist accounts report stripping or releasing roughly 20-25 fry per female, and the young reach about 2 cm (3/4 in) within three to four weeks when fed baby brine shrimp, white worms and crushed flake. Fry can take brine shrimp nauplii from release.

Common Challenges

The species needs a large open sand footprint, so undersized or rock-cluttered tanks suppress nest building and courtship. Males can be hard on females, which is why several females per male are recommended. Stable warm, hard, alkaline water is required throughout the brooding cycle.