Ask A Scientist Zoology Archive

name         Kristen C.
status       student
age          14

Question -   I have two questions. One: The other night I changed my
betta's fish bowl to one of a larger size. Although I had been noticing
him fattening up a bit before hand, about an hour later he was completely
swelled with air. When he struggled to swim to the bottom of the bowl he
floated right back up. He also couldn't swim upright; he kept floating on
his side. I then put him back in his original, smaller bowl and over
night he deflated,and I found many bubbles around the rim. What was this
strange behavior? The vet had no ideas do you? Two: My bettas never leave
bubbles around the rim indicating that they are happy and healthy
although they appear to be. What sort of things do you suggest I do to
ensure that they are? I keep their diet mostly the same and their
lighting is somewhat dim. Do these factors matter? What can I do to get
them to make these bubbles?
-----------------
I have three Bettas and taking in air bubbles is probably the response to
changing water.  Chlorine has a huge impact on fish so if you did not age
the water this could explain very quickly the behavior.  Temperature
variations also have an effect on their behavior with the water temperatures
being just a few degrees different.    If you are certain that neither one of these
explanations are applicable, then I do can not help

Steve Sample
=====================================================