A. This fish swells up with increased salinity, and is highly susceptible to gram negative bacterial infection (cottontail) at zero salinity.
It's funny that you mention this, because this might very well be the problem I had with another Esociform fish (central mudminnow) this past summer. The larger specimens I had in a native community tank were dropping like flies to columnaris, yet no other fish in the tank (including sensitive emerald shiners) displayed any signs of the infection. I tried all of the common recommended medications to no avail - in a last ditch attempt to save the last 2 I dosed the tank with some salt. Lo and behold, a few days later and the last 2 mudminnows were swimming around perfectly healthy as if nothing ever happened, their ragged fin edges regenerating at a rapid pace. Have there been any studies conducted on the relationship between salinity levels and columnaris infection that you are aware of?
Edited by DarkMousy, 26 February 2012 - 04:32 AM.