betta - weird behavior... possible disease?

Question
QUESTION: My tank has been up for about a year now i believe or close to it. I've had it for two and moved a year ago. The tank is a ten gallon, and i have a male betta and assorted mollies (2 adult and 10 babies). So that is about thirteen fish in all. I have an Aqua Tech filter (5-10 gal i believe). I'm not sure on the pH, ammonia, and nitrate levels... and i change the water 2/3 monthly & clean the gravel every 2 weeks (sometimes more when it is dirty).

I found my betta laying on his side today at about 1 am and he just lays there. He'll move if i tap on the glass but just goes back down. He was under the heater earlier but he just seems to do that... i didn't think anything of it...

ANSWER: Hi Amanda;

It sounds like a case of swim bladder failure. Here is a link to a web page about it;

http://www.petfish.net/articles/Bettas/swimbladder_betta.php

I hope he feels better soon...

At Your Service;
Chris Robbins

---------- FOLLOW-UP ----------

QUESTION: do they normally die from it? he died about 3 hours after i found him... oh and after i sent the question before i noticed he had yellow looking stuff near his gills...

Answer
Hi Amanda;

Poor guy. Fish don't usually die from just swim bladder failure all by itself. It sounds like he had more serious underlying problems. Fish can die suddenly from heart failure, stroke, liver failure, etc. just like people can. Since we can't see inside them we just don't know sometimes. I'm so sorry he didn't make it...

At Your Service;
Chris Robbins