Ophthalmotilapia ventralis Breeding Guide

How to breed the featherfin Ophthalmotilapia ventralis: sand or rock bowers, pelvic-fin egg dummies, harem ratios and maternal mouthbrooding.

Overview

Ophthalmotilapia ventralis is a Lake Tanganyika featherfin and a maternal mouthbrooder. Males build sand bowers or carry sand onto flat rock to construct a nest, displaying intense colour to attract females. The egg-dummy lappets on the pelvic fins of this genus are unique among the Great Lake cichlids.

Sexing

Males are larger and more colourful, with longer fins than females, particularly the ventral (pelvic) fins that carry the yellow paddle-tipped filaments. Females are smaller and plainer.

Conditioning

Condition the group on high-quality foods. Keep several females with a single male; usually only one male should be housed per tank unless the aquarium is very large, since displaying males are aggressive at the nest.

Breeding Setup

A large tank with open sandy areas is essential, with a base footprint such as 135 x 45 x 37.5 cm (about 230 litres) suggested. Provide a deep sand bed for the bower, or flat rock if the male prefers to build there. Maintain pH about 7.5-9.0, hardness 8-25 dH and a temperature of roughly 23-27 C (73-81 F).

Spawning Behavior & Trigger

The male excavates a crater in the sand or builds a nest on rock, then displays. The egg-shaped lappets at the ends of his pelvic fins act as egg dummies; the female, deceived into snapping at them near the male's vent, takes up sperm and fertilises the eggs already held in her mouth, mirroring the function of haplochromine anal-fin egg spots.

Egg & Fry Care

The female carries the eggs for about three to four weeks and does not feed during this period before releasing the free-swimming fry. The fry are large enough to take brine shrimp nauplii and crushed spirulina flake from the day they are released.

Common Challenges

Male aggression makes a single male per tank advisable unless space is exceptional, and several females spread out his attention. A large open sand footprint and stable warm, hard, alkaline water are required for the bower display and brooding to succeed.