It happened very quickly, we just got him a couple of weeks ago and he had been a great addition to the the tank and went to work reducing the algae almost immediately. I normally try to find where he is hiding multiple times a day and often he is attached to the glass so I can see his belly pretty well, however last night I noticed that he wasn't moving or breathing and his belly was red. I removed him and took some pictures to see if anyone could help determine what might have caused it.
He is in a 29G tank with 3 GloFish Danios, 4 Pearl Danios, 4 Silver Hatchet, 2 Harlequin Rasboras and a Flower Shrimp. There is also Java Fern, Moss Ball and one other plant I forgot the name of. All fish & plants seem to be doing well, no gasping at the surface, awkward movements or other noticeable issues.
I tend to do weekly 25% water changes however did one extra this week as it looked like I had been over-feeding because there was some fuzzy left over food that I wanted to get rid of and I had also started to notice what I think were some tiny (what I think are) MTS roaming around.
I don't have a water test kit (I will have to get one the next time I am at Ned's) but I don't think that is an issue and I do understand that Oto's can be a bit difficult to acclimate to a new environment...
Thanks,
Geoff