Can Boeseman's rainbowfish Live With Threadfin rainbowfish?

The threadfin is the fish to protect here. Its own profile says it does not belong in a general community tank, because it is easily outcompeted for food and the trailing filaments on mature males are nipped at by common tankmates. The boeseman is not malicious, but its own profile warns that its size and rapid movement disturb smaller, slower fish, and at 11 cm against 4 cm it is nearly three times the threadfin's length.

Water is not the obstacle. Both sit at 27 to 30 °C and pH 7 to 8, the warm, harder end the boeseman needs and well inside the threadfin's very wide tolerance.

If you want both, buy the threadfins in real numbers, ten or more rather than six, and feed for the smaller mouth first: daphnia, artemia nauplii and microworm, offered away from where the boesemani are already feeding. Give the threadfins dense, fine leaved planting to retreat into and enough tank length that the boesemani's swimming does not sweep the whole water column. Ragged filaments on the threadfin males, or fish that stop coming out to feed, mean it is time to separate them.