depends on locality. For the most part they come from sub tropical ranges. Although some of the range does go into more tropical areas, most people who argue "tropical temps" are not considering that the water temps are effected by the water source and not just the climate it's traveling through and/or assuming that their short term success will continue with long term exposure.
If unsure of locality I'd recommend aiming for 23-27c , 74-80F, preferably with some amount of seasonal increase/decrease. This will keep them happy regardless of where they are from, some localities will do fine and maybe even be a bit more vibrant if it went down a few degrees cooler, others might tolerate a few degrees higher, but it's a good range to keep them healthy and happy.
I've just received 3 of what I believe are a gachua variant. Because the species complex is so diverse, it is difficult without a definitive ID to know their ideal temp. I've got mine at 74 F right now.