betta fish fin

Question
i have had my betta for about 2 weeks now he seems to be doing fine but i noticed the other day that part of his butt fin fell off is this normal or what is going on.

Answer
Hi Chris;

Sounds like a case of fin rot. It can be very serious. Here are good articles about it and what to do;

http://freshaquarium.about.com/cs/disease/p/finrot.htm
http://www.bettatalk.com/betta_diseases.htm (scroll down to the finrot section)
http://www.fishjunkies.com/Diseases/finrot.php

I hope he feels better soon...

At Your Service;
Chris Robbins