Hello, this is my first post here as I just found out about this forum last week while waiting for a sponge filter for my new tank. In the tank I now have white cloud minnows (8) and peacock gudgeons (3). I haven’t had many fish before, just two betas and some feeders for my turtle, but one of my betas bloated up and died the next day, so when I saw one of my gudgeons had some bloating compared to the other two, I became concerned. It’s very difficult to get a photo, especially because I just did a water change, but I hope these pictures show it is swelling specifically in the belly.
My first search online lead me to a picture that looked very similar on another forum with a comment saying “it looks like she’s pregnant.” So I tried to figure out if the gudgeon with swelling was female, and it seemed like, from online references (black line on anal fin and less bulged forehead) she was. But then came the next problem: all three gudgeons have that black line. One has a more bulged head (shown here, hopefully, in a photo taken yesterday) but it could be angle. The one I’m concerned about is noticeably smaller as well, about 2/3rds the size maybe? But there’s no behavior that strikes me as irregular or concerning so far, just the belly.
as for water parameters, I changed the water right before so the results may be a little inaccurate, but the gudgeons (as well as the white clouds) have only been in the tank for two days. Please forgive my estimates, it’s very hard for me to see different shades so reading test strips is a struggle. The ammonia I tested before the water change, the rest I tested after.
ammonia <.5
nitrate ~10
nitrite <1
hardness 75-150
buffer ~40
ph 7.2-7.6
chlorine 0
If it does look like an illness, please let me know how I should go about treating it. Thank you!