Petrochromis Trewavasae care guide
Petrochromis Trewavasae (Petrochromis trewavasae) — minimum tank 600 L, temperature 24-27 °C, pH 8.5-9.2.
Overview
Petrochromis trewavasae is a large Tanganyikan herbivorous cichlid reaching about 20 cm, named in honour of ichthyologist Ethelwynn Trewavas. The species inhabits the wave-zone rocks along the Burundian and Tanzanian shores; adults bear a slate-grey body with subtle bluish iridescence.
Taxonomy
- Family: Cichlidae
- Genus: Petrochromis
- Scientific name: Petrochromis trewavasae
- Common synonyms: Goldfin Petro
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: 600 L (158.5 US gal)
- Adult size: 17-20 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.