I cried when my first fish died. It was a black moor goldfish, and yes it was in a goldfish bowl. I was eight and so upset I couldn't sleep. My Mom stayed awake with me half the night, and we played card games - mostly Rummy. In the morning we buried him underneath the flowering almond bush. (Thanks, Mom!)
That was several decades ago. I've not cried since about fish.
Now, mostly I curse out loud. If it's due to jumping I curse more and yell at them about how stupid they are: "Oh H***! S**t! D***! Stupid, Stupid, stupid fish!" If they're small out with the garbage. If it's a big one they get flushed so they don't stink. Though if I think it's some error on my part, ie., CO2 od, wrong dosage of Prime., etc I do feel badly.