One might assert that their dog is happy without relying on the power of speech. Fish do exhibit signs of contentment as well as signs of aggression, sickness and stress. The watchful fishkeeper can gauge a fish's contentness, (aka "happiness") with some degree of accuracy, through a scrutinous observation of their behavior and tank conditions. Truth be told, if you were so concerned about a fish's happiness, you would leave it in the ocean. I too feel that we should do all in our power to promote better fishkeeping; i try to practice what i preach through asking advice concerning possible situations. This is what i was doing when i inquired about keeping a midas blenny and trigger together. I will not do this thanks to the helpful tips of people like you. I really do appreciate the help and i don't intend to offend: but i don't appreciate the condesending tone that you use to deliver it. Furthermore, i see no reason to invest in a 120 gallon tank to keep a 3 inch clown trigger...however, i would do so to keep a 5 or 7 inch trigger.
Thank you- David