Yoyo Loach Thinks It's An Oscar?

[SherLar]

   I have 4 yoyo loaches in 1 tank. 3 have been in the tank for several months. The 4th, I added a few weeks ago because he was alone in a tank at a LFS with African cichlids, and I felt bad for it.
   For several days now, I've noticed it periodically laying on it's side in the tank, always inside a certain rock cave. After a few minutes, or longer, of laying like this, it will right itself and either remain in the cave, or swim away. I've never observed any of the others doing this. I also have several kuhli loaches, and have never noticed this behavior with any of them. It seems to get along fine with the original 3 when it isn't "sulking.'
   Is this a common behavior for yoyo loaches, or should I be worried? It doesn't show any obvious signs of an ailment.

 

[Jeremy180]

I've heard of healthy clown loaches resting on their sides, but not yoyos.
Refusing to school with the othersl can be an early sign of disease among schooling fish, but since you say he gets along fine withe the others, maybe not in this case.
The following is pure speculation on my part, but maybe this is a learned behavior from when he(she?) was in the cichlid tank?
Like maybe this loach learned that if it rested on it's side the cichlids would harass him/her less, possibly because they assumed the loach dead?
Again, just speculation on my part, and as likely as not to be wrong.

 

[SherLar]

   I think that's as likely a reason as any. The tank was bare bottom with little decor, so not many hiding places. I'm not sure why he was even in there. I should have asked.