I have a 29 gallon BioCube that I have been housing my Betta Rubras in since November 2012. I have had them for close 2 years. They have always been healthy - I have never had any health issues with them.
I bought 4 White Cloud Mountain Minnows and 8 Red-Fin Tetras last Saturday, 03/31/13, from a LFS. I performed a 25% water change before introducing them. Since then, 2 of the WCMMs and 4 of the Red-Fin Tetras have disappeared. I can only assume the bettas killed them and something ate them. Not sure if bettas ate them or if ghost shrimp and cory cats disposed of their bodies. I did notice that a couple of the bettas had rather LARGE stomachs after the disappearances.
Anyways, starting yesterday, 04/03, I noticed that one of my bettas was distressed and was white about the face. Her mouth was a little beat up, too. I thought that she gotten in a fight with another fish, so I decided to check on them again this morning. Well, this morning, she was dead. Her body had more loss of color - no fuzz, just colorless scales. Her stomach was also bloated. I am kicking myself for not taking a photo of her.
Now, another female betta is showing the same symptoms, except the loss of coloration is not on her face, but are patches on her body. She does not appear comfortable and her body condition is not ideal. Her belly is bloated. I noticed another betta with a colorless patch on its back. I have attached photos of the one female with the multiple patches. Has anyone seen this before? I honestly have no idea what this is. It looks like it kills them fast, which is upsetting me as I am highly attached to these fish. Could they have caught something this quickly from the new additions of minnows and tetras?
The minnows and tetras do not have any sickly traits.