High temps may be good for tropicals, but obviously, this is only to a certain extent. Once you go over their prefered range, you will see more negative effects (especially long-term) than positive effects. The main difference between tropical, temperate (bass would be considered a temperate fish), and coldwater species is the temperature range they prefer. This is the major reason you shouldn't mix natives with tropical fish.
When I say warmer temps lead to a shorter life span, I'm not trying to say its a bad thing to keep your fish at the upper end of their prefered temp range. All im saying is that a certain fish kept at 80* (barring other factors like food, competition, etc) would not live as long as if you kept it at 70*. Since a cold blooded animals metabolism is controlled by temperature, the warmer it is, the faster its metabolism is. This basically means as you raise the temp, its growing and aging faster.
