why my 3-month-old molly fish cant close their mouths?

Question
Hi Chris Robbins

I'm a beginning in the whole fish thing. Currently, I have a 5 gallon tank, with 1 adult female balloon molly and 15 3-months-old balloon molly (no, that is not their mother).

I have set up this tank for almost 1 month, and nothing serious happened. Occasionally few baby fish died because of defective bodies. Last week, I spot the big one had a cotton mouth so I did a salt bath for it, and it healed by the 3rd treatment.

Basically, the fish seem to do great, they are very active, eat a lot, and they are not aggresive and not fighting each other (at least I don't see that).

Okay, here's the question. I was looking at my 3-month-olds closely, and found some of them couldn't close their mouths!

I first noticed there was one where one side of its mouth fell wide open, while the other side also not moving. Then soon, I found another one where both side of its mouth hanged wide opened (aka, whole mouth wide open). I thought something was terribly wrong, so I gave them a little salt bath. They were still the same. Then, today, I found yet another one where its mouth couldn't close.

The way that they couldn't close their mouth is like, their lips were not moving at all, even when they breath or when they eat. But then, all of them could eat. When I fed the fish, they still ate quickly and ate a lot. Somehow, they could suck in the food.

Is it a bacteria infection, something like the cotton mouth? What kind of medicine I should give to them? Or, is it jaw dislocation? What could be the cause?

I really appreciate your answer and advice. Thank you in advance.

- sasa

Answer
Hi Sasa;

Poor little guys. It sounds to me like genetic deformity. You could try an antibiotic such as "Maracyn" or "Maracyn Two" in case it's a bacterial infection or something. There would usually be redness or inflammation though.

There really isn't anything you can do if it's a genetic deformity. I would avoid breeding the same fish together to hopefully avoid the same thing in other babies in the future.

Good luck...

At Your Service;
Chris Robbins