Of course they do,
our Betta gets as excited as a puppy every morning when we show up to feed him.
Each one we have had over the years has had a distinct personality.
I don't think that really supports the theory of fish having feelings. I'm not sure it requires feelings to respond to repeated stimuli in a way to generates a more advantageous outcome. That's not to say fish don't have feelings, just that I'm not sure this is necessarily good evidence.
> Each one we have had over the years has had a distinct personality
That seems more likely to be indicative of feelings/consciousness in my eyes. Personality, specifically different personalities in the same type of organism, would indicate to me complex learned behavior (what else is personality but that?).
The whole subject of "feelings" is kinda thorny as long as you either subscribe to a worldview where there's no real difference between inanimate and living objects (it's all just a bunch of atoms, it just so happens that some bunches move and some are stationary), or, alternatively, if you do believe in such a difference but have nothing but a gut feeling to rely on when defining the limit between "machines" and "feeling beings." Which means it's a thorny issue for, well, most of us.
So, what I meant was that I'm not sure response to feeding, or imminent feeding necessarily shows of any of the mechanisms I would associate emotions, in my naive understanding of the subject, purely on the basis that I think a similar response could be achieved without emotions. I thin human behavior is complex enough that emotions are evident in most cases, even on short observation. For example, viewing feeding in humans with more than a few individuals would probably show common groupings between the humans after just a short while. While it's possible that this could be the result of extremely complex or finely tuned automata, it's more likely in my eyes that there are more complex feedback mechanisms in place (which to be fair, could easily be classified under "extremely complex automata").
In short, I don't place a huge importance on emotions, as I think they are just an extra mechanism that develops in complex feedback systems for a more advantageous set of responses to stimuli. That said, I think we can look at how organisms respond to stimuli and make educated guesses as to whether emotions are in play or not, and to what degree. I also don't believe there's any real distinction between a machine and a human being. We've just developed feedback mechanisms so complex that they've generated new emergent behavior.