Apistogramma macmasteri

Adults reach a length of approximately 4–5 cm. Males are usually larger than females and have more intense coloration. Depending on the selected colour form, their body can be predominantly yellow or red, while the pattern remains constant: it consists of several dark parallel lines and one dark diagonal stripe running through the eye.

Its natural habitat is in South America, in present-day Colombia. These fish are found in the limited range of the upper basin of the Río Meta, including the Río Metiquía and Río Guayuriba and their tributaries. Originally this region was covered by tropical forests with extensive flooded and swampy areas along the river channels. However, in recent decades the landscape has changed significantly due to intensive agricultural development: tropical forests have been cleared and wetlands drained to create fields and pastures.

These fish behave peacefully and are friendly, especially if kept in a group consisting of one male and several females. In the confined space of an aquarium and with several males present during breeding season, conflicts over territory may arise. Apistogramma macmasteri coexist well with other calm species of similar size. It is recommended to avoid keeping them with other Apistogramma species to prevent interspecific hybridization.

Most Apistogramma macmasteri offered for sale are bred on commercial fish farms; wild specimens are extremely rare. This means their adaptation to aquarium conditions is quite straightforward. These fish will be comfortable in an aquarium of at least 40 litres, equipped with a sandy substrate, live or artificial plants, and several shelters such as driftwood or other decorative elements. Lighting should be kept dimmed, which can be achieved by using floating plants on the water surface. Water parameters should be slightly acidic and have low carbonate hardness. Sometimes, to recreate the brownish water tint characteristic of their natural habitat, tannin extracts or leaves of trees high in tannins are used, such as Indian almond, oak, or European beech. Leaves are dried first, then soaked until they sink, and only then placed in the aquarium. Tannins gradually leach into the water as the leaves decompose, giving it the desired colour. Leaves should be replaced every few weeks. Tank maintenance includes regular cleaning of the substrate of organic debris and weekly partial water changes of 10–15% of the total volume.

As carnivores, in their natural habitat they feed on small bottom-dwelling invertebrates, including crustaceans and insect larvae. In the aquarium it is recommended to include live or frozen foods such as bloodworm, daphnia, and brine shrimp. As supplementary or alternative feeding, sinking commercial foods (flakes, granules) enriched with protein can be used.

When optimal conditions are maintained, including suitable water parameters and temperature, as well as balanced feeding, the chance of successful fry production is very high. During spawning the female selects a shelter and deposits up to 120 eggs. Her maternal instincts are fully expressed: she remains guarding the clutch, then will protect the newly hatched fry, which stay close to her. The male also participates in offspring protection, but sometimes his behaviour becomes excessively aggressive, and he may need to be temporarily moved to a separate tank. If several females are kept in the aquarium, all of them may produce offspring. In such a case it is important to ensure that the number of shelters matches the number of females and that they are located in different areas of the aquarium.

The main cause of most diseases in these fish is unsuitable keeping conditions and poor-quality food. If initial symptoms are detected, first check the water parameters and the concentration of harmful substances such as ammonia, nitrites, and nitrates. If readings deviate from normal, they should be corrected before treatment begins.

When buying, choose active individuals with clean fins and no visible damage on the body. Avoid fish with sunken bellies, signs of emaciation, or unnatural behaviour such as constantly sitting in a corner when attempts are made to interact. In healthy Apistogramma macmasteri, the eyes should be clear and the coloration sharp and vivid, matching their species standard. Inspect the aquarium in the shop for the absence of dead fish in the same tank. Ask the seller what food the fish is fed on so you can ensure a smooth transition to your diet. Prefer individuals that show curiosity and respond to movement at the glass.