[Dandy Don]

Last October, I bought six Paracyprichromis Nigrippinnis. For about three months, they all seemed to be thriving, getting along well. I have a 135 gallon tank with a 3-D rock background and lots of rocks and other hiding places on the ground.
In the last two months, four of them have broken off and hang out alone, not at the top of the tank, but alone.
They have turned brownish in color, most likely due to some sort of stress. I removed them and put them in another tank. They were easy to net and didn't react until they felt the netting. The remaining two are flourishing, very active, good color.
The four in the separate tank all hang vertically on the glass at the surface. They don't react to food unless I place it right in their face. And then they pick blindly at the surface until they find a piece of food. They spend 75 percent of the time picking at the water surface where there is no food. I'm convinced they've done blind, but their eyes look normal.
I've never seen this before. Any thoughts?

 

[noddy]

Do the four that stay to themselves show any blue colouring on the tips of their tails?

 

[Dandy Don]

I don't think so. (I'm at work)
One or two of them have returned to normal silverish color, one of those was actually getting blue in the dorsal fin.
But I don't think I've ever seen blue in their tails. Why?

 

[noddy]

I don't think so. (I'm at work)
One or two of them have returned to normal silverish color, one of those was actually getting blue in the dorsal fin.
But I don't think I've ever seen blue in their tails. Why?

The males will separate and not hang out together once they start to mature.
Hanging vertically against the glass is what they do if there are no caves to hang upside down in.
To be honest, you have described normal male paracycyp behavior They shouldn't be silver at all.
They are a red/brownish fish and the males develop blue lines on the body, the tail, anal, ventral and dorsal fin.
Can you post a photo?

 

[Dandy Don]

But what about the problem finding the food?
If they're not blind and this is normal paracyp behavior, I don't know that I should put them back in the 135.

 

[noddy]

But what about the problem finding the food?
If they're not blind and this is normal paracyp behavior, I don't know that I should put them back in the 135.

I read your post as they were not reacting to food since they were moved into another tank.
I read it as you moved them because they were separated, turned brown and hung out alone. That is what I consider to be normal behavior.
Were they not eating before you moved them? What are you feeding them? What size tank are they in now and what are their tank mates?
I have 10 adults in a 210g tank with eight more growing out in a 40g long.

 

[Dandy Don]

In the main tank, they were separating themselves, and it appeared they weren't eating. They turned brown while still in the main tank and food would pass right by them.. They had been active, less dark and eating. I feed them flake food.
Since they've been in the new tank, I've also tried to give them frozen brine scrimp, but it passes right by them. They literally don't eat unless I drop it right in front of them and they feel the surface tension of the water change.
They are a little bit smaller than the other paracyps that are thriving are certainly more gaunt.
They are bigger, longer that most tank mates except for a pair of Dickfeldi julies that sort of run the tank.