Trematocranus placodon Breeding Guide

Breeding the snail-eating Trematocranus placodon: sexing, harem setup, pit spawning, broods of up to 100 eggs and three-week maternal mouthbrooding.

Overview

Trematocranus placodon is a Lake Malawi haplochromine that functions as a molluscivore in nature, using specially developed pharyngeal teeth that crush and grind snail shells with ease. It reaches a maximum standard length of about 25 cm. Seriously Fish describes it as a polygamous maternal mouthbrooder, and it accepts most aquarium foods, with snails offered when available.

Sexing

Adult males are slightly larger and far more colourful than females; the record notes males turn blue with yellow flanks. Colour and the male's spawning behaviour make sexing straightforward once fish mature.

Conditioning

Condition adults on a varied diet including live, frozen and dried foods, with snails as a natural component. Seriously Fish lists 24-28 C, pH 7.6-8.8 and hardness 10-25 dH, close to the record's 24-27 C, pH 7.8-8.6 and GH 10-20 dGH. Stable water and good feeding bring fish into spawning condition.

Breeding Setup

Males are highly territorial toward each other, so keep one male per tank (under about 72 inches / 180 cm length) with multiple females; the record lists a minimum of 400 L. A sand substrate lets the male dig and maintain his spawning depression.

Spawning Behavior & Trigger

The male digs and defends a depression as his territory and displays vivid colour to attract females. A receptive female approaches the spawning site, deposits eggs, and allows the male to fertilise them before collecting them in her mouth. Up to about 100 eggs may be produced.

Egg & Fry Care

The female does not eat during the roughly three-week brooding period, and her mouth becomes visibly distended. The fry are large enough to accept brine shrimp nauplii from the day they are released, which simplifies their early rearing.

Common Challenges

The main challenge is male-male aggression, which is intense, so a single male and adequate tank length are essential; otherwise this is one of the more straightforward Malawi haps to spawn given clean alkaline water and a settled harem.