Petrotilapia tridentiger Breeding Guide

How to breed Petrotilapia tridentiger, a large Lake Malawi maternal mouthbrooder: harem setup, sexing, conditioning, egg-spot spawning and three-week fry care.

Overview

Petrotilapia tridentiger is the type species of Petrotilapia, a genus of cichlids endemic to Lake Malawi described by Trewavas in 1935. It is a large algae-grazing mbuna of the rocky shore that, like almost all Lake Malawi cichlids, reproduces by maternal mouthbrooding. The female incubates the eggs in her mouth and releases free-swimming fry after about three weeks. Because the species is large and very territorial, breeders work with mature groups in spacious tanks rather than single pairs.

Sexing

Males are strongly coloured, showing a blue body with vertically barred patterning, yellow markings on the throat and around the lips, and egg-shaped spots on the dorsal and anal fins. Females retain a duller brown to grey appearance and the same barred pattern without the blue overlay. Dominant males develop the most intense colour and aggressively hold a territory among the rocks.

Conditioning

Although the genus is adapted to comb aufwuchs from filamentous algae on rock with specialised teeth, P. tridentiger is reported to be a more omnivorous feeder that takes zooplankton, phytoplankton, detritus and even fish fry and eggs when available. A varied vegetable-rich diet keeps breeding stock in condition; over-feeding rich animal foods is avoided in algae-grazing mbuna to reduce digestive problems.

Breeding Setup

A harem of one male with two or more females is recommended so the male divides his attention and a single female is not constantly chased. Because adults reach roughly 12-19 cm and males defend rock dens, a large aquarium is essential; sources recommend a tank of at least 200 cm in length (around 750 litres) with plenty of rockwork to break sightlines and provide spawning territories.

Spawning Behavior & Trigger

A dominant male establishes and cleans a territory among the rocks and displays to receptive females. The female deposits eggs and immediately takes them into her mouth; she then attempts to collect the egg-like spots on the male's fins, at which point milt is released and the eggs are fertilised inside her mouth.

Egg & Fry Care

The female carries the developing brood in her mouth for about three weeks, after which she releases free-swimming fry. A heavily decorated tank with abundant rock cover gives fry refuge in a community of robust mbuna.