Dead Betta Male

Question
Today I  bought a male betta fish, and I put it in fish bowl. It looked pretty happy, but a couple hours later it was floating belly-up and dead!! I dont know why. It didnt even make t through the night. I am not sure if the problem was that the rocks that I placed at the bottom of the bowl were from the ocean, so they were salty, or that water was maybe not cold enough. Is it bad to put saltwater rocks at the bottom of the bowl?

Answer
Hi Janette,
  The saltwater rocks could have led to the death..., but did you know when the fish is still in the bag of water it came in your sposed to float the bag of water in your tank or bowl for 15 to 30 minutes to get it used to the water. It's okay if you didn't know that but next time do it. Also you should get some rocks from your local pet store. This is because the rocks you used probably carried disease. So next time you go get another beta. Clean out the bowl get some rocks and the fish. Dump the rocks in then the water then put your beta in and everything should be fine.
               sincerely,
                     Samantha