Hi!
Please excuse this English-language post. Although my grandfather came from Austria and my family is in fact named after the giant Wels catfish of the Danube River, we have lived in South Africa since the 1930s and the German language has been lost.
I have a quite new 40-litre planted tank with 1x
Betta splendens, 7x Neon Tetra and 4x
Corydoras sterbai. The tank is kept at 25 degrees C. The fish are fed commercial crumb-type food. I used to keep many aquariums in the late 1980s. This is the first fish tank I have set up since then.
The fish were all obtained about a month ago. The tank has been up and running for about 6 weeks. In the last two weeks I noticed one of the C. sterbai (Cory #1) had a very small patch of fungus (1mm across) on its forehead between its eyes. This fungus has not become bigger in this time.
In the last two days I noticed another of the C. sterbai (Croy #2) has a larger patch of semi-transparent fungus in front of its dorsal fin. The dorsal fin of Cory #2 is also not whole; it has never been whole since I got the fish, but it might be rotting back, I am not sure.
All the fish in the tank are behaving as if they are very healthy. The Neon Tetras even showed spawning behaviour two days ago.
I have uploaded photos of Cory #1 and Cory #2 to this link:
https://www.dropbox.com/sh/9geu6jjj36m0k…h4Z2uOejha?dl=0
If anyone could help with a diagnosis and advice on how to treat this fungus with the minimum of disturbance to the other fish in the tank, I would be most grateful!
Thank you very much!
Adam Welz
Cape Town, South Africa