Added some new fish and plecos, the blue eyed didn't care for the new comer, then he started to shake his entire body, never see that behaviour in a pleco before.
I find that my blue eye is the most aggressive fish that I have. He constantly asserts his dominance and actually spears other fish with his interopercular spines. He actually attacks the jardini in the tank.
He is very active now, he swims all over the tank, goes out of his way to find the pleco. I will move the new guy so not to stress the blue eyed, he doesn't care about any other pleco in there except for the one.