While the true Apistogramma viejita has only rarely been seen in the hobby, this variant of Apistogramma macmasteri is virtually indistinguishable, and is typically sold under this moniker. This is a larger variant of MacMasteri, with adult males sometimes exceeding the 4" mark. In my personal opinion, this is also one of the most beautiful Apistogramma

In their natural habitat, like most Apistogramma , these fish come from soft, relatively acidic water, and these conditions may be required for successful spawning, though MacMasteri tend to be fairly forgiving of water conditions, provided extremes are avoided.

MacMasteri tend to be among the more aggressive species of Apistogramma , especially when spawning. They are territorial and will protect their favourite coconut shell, cave, or other structure. The males can be aggressive toward each othe, and only one should be maintained. It is not unusual for a younger, 'subdominant' male to take on the colouration and apperance of a female to avoid aggression from the dominant male -- which can be frustrating for those who think they have a pair!

These fish mix well with other small, peaceful fish, such as Glowlight Danios, rasboras, hatchetfish, and Pseudomugil spp. rainbowfishes.