Two days ago I got a new betta, I fell in love with him while getting some plants at petsmart. (D: ) At the pet store he was one of the most energetic fish there. Flaring at the females despite his small size, and swimming around his cup like a maniac. I thought I'd have trouble with keeping him in my temporary desk tank!
But now he hardly moves, he just lays at the bottom of his tank or on his leaf hammock. He only ever swims up to get air then sometimes floats there or in the corner of his tank for a second before floating back down.
I know he's not too terribly fearful of me because he swims really slowly around the where he can see my face better.
He won't respond to food.
I literally have to touch him with my net to get him to move sometimes.
It may be a petsmart thing? Just getting used to a new environment? I'm so used to the fish I got from a mom 'n pop fish store. He is friendly and energetic. Pictures will come after work. I don't /think/ he has stress stripes but it's hard to tell.