So... sooner rather than later I will be getting my very own betta. I was wondering whether anyone had tips on choosing a betta. If you choose wisely, do the petstore bettas usually do alright... or are they usually prone to diseases and things right off the bat?
Some already have diseases in their cups. But if you give them a good home they should be fine. When you're looking try to find one with a mine bubble nest. Or you could do what I did with Ember, I took the two I really wanted and put the cups next to eachother to see who would flare first and he did. So I got him.
like rb500 said, fin rot is very common. many bettas will already have it when they are in their cups. if their fins/tail have any holes or splits in it, thats a sign of fin rot. i personally haven't gotten any of mine with bubble nests already, but i have seen them before :) and you can keep your betta healthy with lots of TLC. good luck choosing your first betta! i hope you post pics!
Try to get one that's a dark color- a lot of illnesses make the fish pale and it's hard to tell if a light fish is supposed to be light or not- so just save a headache and get a dark one- blue, turquoise, purple, dark red, or steel. Stay away from yellow, pink, or anything with white. You want to look for a nice dark head and a fish that's not just lying there limp, and if the fish is lilting to the side stay away. Sometimes a fish will be obviously healthy- shining and flaring up and being really active. Sometimes the fish is healthy but asleep. Just take the time to check them out properly before you buy one.
I like to look for fin rot also and how their coloring it...its not so easy to tell if they are fading in color if they have some white on them, but just look closely at how their coloring is in pattern, that what i do, and i also see how they react to me messing with the cup and also what they do when they see another betta, as long as they dont act lethargic or like they dont care, than i think they're good :)
But you also don't want a fish that's spazzing out- freaking out and twitching at nothing- that's a stressed out fish. The fish should be alert and interested and maybe a little pissed off- but not overly stressed out.