Petrochromis Polyodon care guide
Petrochromis Polyodon (Petrochromis polyodon) — minimum tank 700 L, temperature 24-27 °C, pH 8.5-9.2.
Compiled by Aquairi from published sources · Published · Updated
Overview
Petrochromis polyodon is among the largest Petrochromis, reaching about 22 cm. The species is widely distributed in Lake Tanganyika across both rocky and intermediate habitats; the body is robust and slate-grey to bronze, with extensive blue iridescence on the head and fins in breeding males.
Taxonomy
- Family: Cichlidae
- Genus: Petrochromis
- Scientific name: Petrochromis polyodon
- Common synonyms: Texas Red
Habitat
Endemic to Lake Tanganyika, where it grazes the algal turf on rocky shores. Tanganyika water is hard and alkaline (pH 8.5-9.2, KH 12-20), with stable warm temperatures and very high dissolved oxygen. Petrochromis species are confined to specific stretches of shoreline and form large foraging groups over the upper rocky zone.
Tank requirements
- Minimum tank volume: 700 L (184.9 US gal)
- Adult size: 17-22 cm
- Temperature: 24-27 °C (75-81 °F)
- pH: 8.5-9.2
- GH: 12-25 °dGH
- Water flow: medium
- Lifespan: 10-15 years
- School size: ≥6 individuals
Diet
A strict aufwuchs grazer with tightly packed comb-like teeth used to scrape biofilm from the rocks. In aquaria a vegetable-rich diet of spirulina pellets and blanched vegetables is essential; protein-heavy diets cause severe bloat. Large adults consume substantial quantities of food.
Compatibility
Aggressive and territorial; demands very large tanks (500+ L) with extensive rockwork and a single-species colony or pairing with other large herbivorous Tanganyikans. Do not mix with smaller mbuna-style fish that cannot withstand the pressure; multiple males must each have enough rock territory.
Breeding
A polygamous maternal mouthbrooder. The male defends a small flat rock and entices females to spawn; the female holds eggs and wrigglers for about four weeks before releasing the fry, which already feed on aufwuchs.
Conservation status
IUCN Red List: see species page. Most Petrochromis are widely distributed within Lake Tanganyika and assessed as Least Concern; however, the genus is collected for the ornamental trade and shoreline-specific morphs are more vulnerable.
Breeding Petrochromis polyodon
Overview
Petrochromis polyodon is a robust algae-grazing cichlid endemic to Lake Tanganyika, where it inhabits rocky substrates and grazes biocover alongside other herbivores such as Tropheus moorii. It is a maternal mouthbrooder, in which females incubate the fertilised eggs orally. As with all Petrochromis, breeding follows the genus pattern documented in detail for P. famula.
Sexing
Sexual differences are subtle. Following the genus description on Seriously Fish, mature males are more colourful and develop pointed dorsal, anal and pelvic fins, whereas females stay plainer. Confident sexing usually needs adult, conditioned fish.
Conditioning
Petrochromis are dedicated rock-grazers and must receive a high-fibre, low-protein diet to mirror their natural intake of rasped algae. Vegetable-based foods such as spirulina flake and blanched greens should form the staple, with rich foods used only sparingly to avoid digestive disorders. A spacious colony in clean, well-oxygenated water maintains breeding condition.
Breeding Setup
Given its size and aggression, this species needs a very large aquarium with a rocky layout offering grazing surfaces and visual barriers. A single male with several females is the standard breeding group, and aggression is best managed by keeping the colony with robust tankmates. Hard, alkaline water at 24-27 °C suits the species.
Spawning Behavior & Trigger
Spawning follows the maternal mouthbrooding model: the female collects the eggs into her mouth for fertilisation and carries the brood. Good water quality and consistent conditioning on a herbivorous diet are the principal triggers, with the dominant male courting females within his territory.
Egg & Fry Care
Based on the closely related P. famula, the female holds the brood for around four weeks without feeding. Released fry are comparatively large and take adult-sized foods soon after release, growing quickly with frequent feeding. They should remain on the same fibre-rich, low-protein diet as adults.
Common Challenges
Aggression and diet-related bloat are the chief obstacles. The species' large size demands substantial volume, careful tankmate selection and a disciplined herbivorous diet to keep the colony stable and spawning.