Betta Ill?

[Rogue4Fish]

Hi
 
I got myself a new Betta about 4/5 weeks ago, "Peanut". He had settled in fine, but all of a sudden i've noticed he doesn't seem himself. He constantly seems to lay flat on the top of my filter on the rock. He's very skittish and instantly hides if he feels anyone is around his tank and doesn't seem to be swimming around at all. This only seems to have occured over the past couple of days...health wise, he does eat, eventually. He doesn't come up to the top of the tank when it's feeding time.
 
I can't see any marks, lumps on him, he actually looks in good condition. Doesn't seem bloated or what not.
 
Water parameters are fine. Although the tank is new, I took filter media from a well established tank. I done a 50% water change this morning, he's exactly the same this evening. I would go as far as to say he's scared of the light that's on in the tank.
 
He's not the first betta i've owned, but I've not seen this behaviour before.
 
Any input would be helpful, thanks.
 

"Peanut"

 

[Awilcox]

Temperature? What have you been feeding him? Bettas can be tricky contrary to popular belief. Is he laying or floating? My bettas are very prone to swim bladder problems. Try taking off the light if it seems to be bothering him, see if it helps.