If you are looking for a tropical tank mate a zebra danio is one of the best they are extremely fast and agile and wont be caught by a trimac. If you are lookin for a cichlid tank mate you should go for a female trimac or a midas, make sure you introduce the trimac first to the tank so it can establish dominance over it. A trimac pair would need a tank close to 120 gallons, a trimac with a midas would need a tank close to 150 gallons, and a male trimac by itself would need at least a 75 gallon.