Breeding Neolamprologus similis

Breeding guide for Neolamprologus similis, a colonial Tanganyikan shell-dweller that spawns inside empty snail shells, with eggs hatching in about 24 hours.

Overview

Neolamprologus similis is a tiny shell-dwelling cichlid endemic to Lake Tanganyika, with males reaching about 4.5 cm and females about 3.5 cm. It is a shell brooder: pairs and colonies lay and guard eggs inside empty snail shells. Highly territorial despite its size, it defends a very small area, roughly 15 cm across, with vigour.

Sexing

Adult males are considerably larger than females and may develop a small nuchal hump as they mature. Within an established colony this size difference is usually the clearest indicator of sex.

Conditioning

Live and frozen foods should form the bulk of the diet, with dried foods accepted but never fed exclusively. Well-fed fish kept in stable, hard, alkaline water at 24-27 °C readily come into breeding condition.

Breeding Setup

Provide fine sand and plenty of empty snail shells, with more shells than fish. If a group is kept it forms a colony; keep more females than males and space the shells out to reduce male-to-male aggression. A single male may spawn with several females. The breeding pH is best around 8.0-8.5.

Spawning Behavior & Trigger

The female displays at a shell entrance until the male responds. She then enters the shell to deposit eggs and backs out as the male releases sperm at the entrance, fertilising the clutch. Stable water and abundant shells trigger spawning.

Egg & Fry Care

Eggs hatch in approximately 24 hours, and fry become free-swimming around day six or seven, at which point they accept brine shrimp nauplii or microworm. The female tends the brood within and around the shell.

Common Challenges

Aggression between males in a confined space is the main issue; providing enough shells and spacing them well prevents most conflict. Because territories are tiny but vigorously defended, even this small fish needs a sand-bottomed tank designed around its shell colony.