Common Natron Tilapia

About

Found only in Lake Natron and its surrounding catchment on the Tanzania-Kenya border, Alcolapia alcalicus occupies one of the most extreme aquatic environments on the planet. Lake Natron is a shallow, searingly hot soda lake loaded with sodium carbonate and dissolved minerals, with pH values routinely above 9.5 and temperatures that would kill virtually any other fish. This small cichlid has evolved some remarkable physiological workarounds to cope. It excretes urea through its gills rather than ammonia, since releasing ammonia into such heavily buffered, alkaline water is essentially impossible. It also gulps atmospheric air at the surface when dissolved oxygen runs low, a behaviour that becomes less common in the more oxygen-rich conditions of an aquarium. In the wild it feeds primarily on algae during the early morning hours, supplementing that diet with copepods and insect larvae. Captive specimens can be gradually acclimated to more moderate water conditions, though the pH should never be allowed to drop below 8.0. Breeding has been achieved in aquaria. Males dig spawning pits in the substrate and females are maternal mouthbrooders, sometimes carrying eggs fertilised by multiple males simultaneously. This is an endangered species with a very restricted natural range, and genuinely rare in the hobby, so finding it requires some searching. Intermediate keeper experience is recommended.