What's going on with my pea puffers' social order?

[memorywrangler]

Last November I got 9 juvenile pea puffers.  They matured into 2 males and 7 females, and eventually I started to see spawning behavior with the bigger male following an nudging one or more of the females.

Then, tragedy struck:  The dominant male and one of the females jump out of the tank and behind a cabinet 😞.

Shortly after, I tried moving the remaining male and 2 females into a smaller tank in hopes they would spawn.  The seemed pretty unhappy in there, and I moved them back to the original tank.

In 3 months since, the personality of the group has changed dramatically:  Thy are more shy and they don't hunt as aggressively as they used to:  they used to attack blackworms and snails and now they just pick at them.  The remaining male doesn't seem to have risen to the occasion and don't see anything resembling courtship behavior.

Has anyone had a similar experience?  Any suggestions on how I can encourage the remaining male and females interested in spawning?  Are they depressed?  In mourning?

 

[Odd Duck]

They might have picked up some parasites?  No matter how careful there’s always a chance for parasites when feeding live foods or meaty foods.  If your water parameters are all OK, then I would consider a round of treatment with levamisole.  You might want to move them to a hospital/treatment tank for it even though I know it’s hideous to try to catch them.  Levamisole will likely affect any snail colonies you might have in the tank.

Edited July 29 by Odd Duck
Clarify.

[Beardedbillygoat1975]

@Odd Duckhas a great point. The stress of these events could have brought out something. I’d do paracleanse and then levamisole.  

If their behaviors don’t change I’d get a dither fish. White cloud minnows or a dwarf rasbora would be a good choice. Something fast that won’t be too hard for them to deal with. It’s always a risk but sometimes I’ve seen them react positively to having others in the tank. Other times they’ll kill them.