I saved a betta from wal-mart a couple days ago. I went to look at the fish and there were 2 containers with absolutely no water in them and a fish in each. So I opened one of the betta water bottles that they sell and added water to each of the containers. So of course I had to take the one that didn't look like it was going to live, but it did. Anyway...the one I bought can't swim downward, it struggles to go to the bottom, so he just stays at the top most of the time. He also seems to have a curved spine, like an s shaped of some sort. Does anyone have some advise as what might be wrong with him? His appetite is normal, wants to eat all the time. Oh yeah, he also has silver or grey patchy looking spots around his gills. Any opinions would be helpful.