This has never happened in any of my tanks, and I don't know which fish would be the culprit, as I've had this community as-is since the end of December(I think? Susan may remember), and have had natives in there for almost two years. 

One of the redside dace and one of the minnows are each missing an eye. I have no idea which of the fish I have could be doing this to the others, as I've had some of(in some cases the same individuals, not just same type) everything but the redside dace in there the whole time I've had this tank running and this has never happened.  I added the redsides, the current darters, and the juvenile bristlenose in Dec.  The adult bristlnose has been in there over a year, as have all the other inhabitants.

Tank: 75g freshwater native stream tank, no heater, powerhead with spray bar for flow.

Feeding: mysiss shrimp or bloodworms(frozen-- thawed before feeding)

Inhabitants:

• redside dace(several)
• redbelly dace(several)
• sucker (1)
• mad tom(1)
• bristlenose pleco (2- one adult, one juvenile)
• Johnny darters
• greenside darters
• shiners/minnows (just a couple)
• mud minnows(3-4 of them, 2 years in the tank)

Help!  I want to remove whichever fish is/are doing this!

bumping because I have no idea what to be looking for as to which fish might be causing this.  It's not a fungus, and nobody is missing parts of fins or tails.

This is so out of my knowledge base.

Sorry Mare, I'm no help on this one. Has anyone seen Farmer Todd? Maybe he could shed some knowledge on this.    

I'm not that familar with natives, but if you don't mind waiting the last one that still has eyes will be your culprit.

Trilby Tropicals said :

I'm not that familar with natives, but if you don't mind waiting the last one that still has eyes will be your culprit.

Seriously though-- you do know plecos.  Would the bristlenose do something like this?  I have an adult that 's a couple years old(he was at least a year old when I got him, and I've had him a year) and one of Susan's youngsters-- don't remember how long ago hers reproduced, but it's less than a year.

You never know for sure, that's part of the joy of keeping fish. We've had bristlenose in with many different types of fish before with no missing eyes. We've had them in with bigfish, little fish, striped fish, spotted fish, in big tanks, small tanks, square tanks, round tanks, tall tanks, short tanks. (Who now has that started repeating in their heads  ) Basically what I'm saying, it's not likely the bristlenose doing it, but I wouldn't rule anything out, maybe you have the one that has a taste for eyes? (Who knows maybe Susan put fish eyes in her fish food?)

Trilby Tropicals said :

(Who knows maybe Susan put fish eyes in her fish food?)

Not on purpose!