I have had four danios (3 zebra, 1 leopard) for close to a year now. They were initially in a 10 gallon tank but have since been moved to my 36 gallon. Recently one of them has developed a swollen belly and at first I thought she (?) was full of eggs. I don't know how to sex them so I'm not sure if she is even a she. The tank has been running for almost two months now and the water parameters are in check. I test with the API liquid master kit and things are 0, 0 and 5. The ammonia did fluctuate to 0.5 - 0.25 briefly about a week ago but levels have since been brought down. I do weekly water changes of about 20%. Aside from the danios, I have black skirt tetras, platys and a dwarf gourami in the tank. (Sorry the pictures are sideways. My iPad did that for some reason.) Do you think she's full of eggs or is it something else? I keep a close eye on her and she swims normally and eats. She just has a really big belly!