The role of diseases and beahvior?.

[Maccus]

I had mentioned that I was thinking of giving away some fish having mystery behavior problems due to gas money.
The reply I got was nobody wants a bunch of old sick fish. This got me thinking, do fish diseases cause longer term behavior problems?. I know diseases can lead to more immediate behavior issues, just didn't see diseases causing longer term behavior problems.

[mummymonkey]

Some diseases can physically damage the fish without killing it causing it to modify its behaviour is some way for the rest of its life. Some examples might include blindness, loss of or damage to fins and barbels, fertility problems and damage to the nervous system.

[Maccus]

So would nervious system damage cause fish to frequently gather in a corner for a couple of weeks?.

[Bas Pels]

Some diseases can physically damage the fish without killing it causing it to modify its behaviour is some way for the rest of its life. Some examples might include blindness, loss of or damage to fins and barbels, fertility problems and damage to the nervous system.

And if the deseases don't coause them, the medicatioons might do it for them

Many of the medications in use are very agressive, and might cause infertility, and so on. As a rule, the medications are not allowed for humans, or for animals intended to be eaten by humans. That alone would alarm one.

The problem is, the alternative might be loss of the fish

[mummymonkey]

So would nervious system damage cause fish to frequently gather in a corner for a couple of weeks?.

No idea, but wouldn't rule it out.