Ok, So i was doing some normal tank maintence today, water change, Gravel Cleaning, All that. And i put my VT betta in a small container. I then noticed that his left gill is sticking out. He is swimmming normally but his gill movement is fast. I dont know what happened but his gill is sticking straight out. He is not flaring, it is just 1 gill and it isn't moving at all, It is just sticking straight out. I really need help. Please let me know if there is anything i can do.
Here are some pictures so you kinda have an idea of what it looks like.
I dont know if he caught it on some fake plants or what. Also the tank is around 72 degrees.