Bettas Bulgy Nostril

Question
Hello again, I've got another question! My older male Betta, Elmo, was discovered as passed away this morning.. His "girlfriend" Zoe is alive but possibly not well. I noticed, after cleaning the tank and putting her back in, that the area surrounding her right nostril seems to be puffed out, causing her face to look uneven. Naturally I felt very alarmed. Could this be some sort of disease, like cancer or a tumor or something? Could it have anything to do with the death of the other betta (like a bacterial infection)?
I am wondering what I should do for her. On Tuesday I have scheduled to go get her a new companion, either a new boyfriend, or some non-aggressive fish (tetras probably). For the record, it is a 2.5 gallon tank. Thanks in advance for any advice.

Answer
Hi Teneisha;

It may be a bacterial infection from an injury. Keep her water very clean and if it seems necessary, use an antibiotic such as Maracyn or Maracyn Two. Aquarium salt is helpful too and can be used with the antibiotics. Make a water change too, 25%.

I really can't recommend that you add any more fish to her tank at all. It's only big enough for one betta. Bettas should not be kept together all the time, even a male and a female. She would probably chase and eat smaller types of fish too. Even if you didn't have a betta in there, the tank is only large enough for two or three small types of tetras. The general rule for small community fish is to have one inch of fish for every gallon of tank water. A betta typically gets about 2 to 3 inches. Smaller types of tetras get to be about an inch. You can only safely have one or the other.

They may have been fighting and injured each other. They may do okay for quite awhile and suddenly turn on each other. Only put a pair together when they are actually ready to spawn and then remove the female so the male can care for the eggs and babies. Bettas can be violent breeders. The male can injure or kill the female trying to induce her to spawn, or to her get her away from his nest, or the female can injure the male too. They can't help it, it's just their nature. It insures that the strongest fish earn the right to breed and pass on their strength to the next generation.

I hope she feels better soon...

At Your Service;
Chris Robbins