betta is very sick

Question
I just got a betta about 3 months ago with 2 tetrus and a bottem eater which was in the same tank as the betta. The betta is a male if that changes anything I really do not know. about a week ago one of the terus died and now about 2 days ago the other one did too. the bottem eater looks and acts normal. the betta on the other hand has been acting weird. he will only lay next to the light(my bulb burnt out and we havent found the right size yet so i have a lamp next to the tank it does not get hot because it is a eletric efficent light bulb. one eye is cloudy and on the same side he has weird marks or red and white and grey underneth his chin area. he has not eaten from what i have seen. he acts blind have the time. Im not sure what to do or what it is. he also goes to the top of the 5 gallon aquarrium and gets air and then he goes back to his spot about every 5 mins then ive notice that his fines open and let out bubbles of area..
please help

Answer
Hi Danielle;

If your betta has long fins it is a male. Females have short fins. It is normal for bettas to go to the top and take a gulp of air. Some of the air may expel a bit too after they gulp from the top. Bettas have a breathing organ called a labyrinth that holds air for them to use. This is so they can live in low-oxygen water like their wild natural environment is. Gouramis have this organ too. If the water has low oxygen, they can't get enough through their gills so their bodies use oxygen from the labyrinth instead.

He may be too cold. Raise the water temperature to 78 to 80 degrees. Bettas are tropical and need it warm all the time. Make a water change too. You should replace 25% of the water every week for good health in your fish. This may perk him up too.

Could the catfish be picking on him? Sounds kinda weird that he is the only healthy fish left. What does he look like? Maybe he is an aggressive kind?

At Your Service;
Chris Robbins