- Scientific name: Apistogramma macmasteri
- Common name: Macmaster's Apisto
- Group: Cichlids
- Habitat: South America; Colombia, Orinoco Basin
- Size: Male: 7 cm; female: 4-5 cm
- Biotope: Inhabits in upper Rio Meta and its tributaries
- Social behavior: Peaceful, but during spawning they become territorial and aggressive.
- Diet: Carnivorous, wild caught fish only accept live foods, but once settled they eat frozen or flake foods too. Occasionally feed with vegetable or spirulina.
- Breeding: Quite easy
- Tank: Minimum 65 litres
- Population: 1 male and 2-3 females for 90 litres.
- Decoration: Needs a tank with dense vegetation and cave-like hiding places among rocks and roots. Or simulate their natural habitat with lots of roots and branches, and a substrate of sand with leaf litter on it.
- Temperature: 24-28°C
- pH: 5.5-6.8
- Hardness: 1-5NK°
- Lifespan: 3-5 years
Description: There are 2 color forms of Macmaster's Apisto in the wild: the A120 (wild yellow) and A121 (Red Shouldered). The base color of the wild fish is brownish, and there are two dark grey lateral band at the base of the dorsal fin and on the flank. Male fish is larger and has more pointed dorsal fin, and also has yellow caudal fin with red edges. Females are often yellow, and during spawning their pectoral fins become black. Most wild Apistogramma macmasteri do not exhibit the intense colors that are found in some aquarium strains. It is likely that Apistogramma macmasteri has been interbred with Apistogramma viejita to produce these very colorful fish. The highly colorful aquarium forms have an iridescent blue body with more or less red patterns on their head.
Breeding is not too difficult, with soft, slightly acid water (use the water parameters above). Shelter breeders, the female will lay 60-100 eggs on the roof of a cave. After spawning the male guards the territory, while the female takes care of the eggs. The eggs hatch after 48 hours and after another 4-5 days the young fish become free-swimming. They can be fed with baby brine shrimp.