Dancing Fish?

I'm a very newbie fish enthusiest... 55 gal white sand bottom only 3 fish. (1) Electric Yellow, (1) GT or BA (cant get anyone to clearly identify) and a placo (enourmous and holding his own w/NO issues from the cichlids)

My GT (or BA) does this jerking, jittering, quick back and forth dance in front of the front glass.. often.. and w/NO warning will JOLT across the tank with speed that makes sand spin under him (or her) and in the past few days has developed a bright yellow/orange edge to his top and tail fins.

Any input would be greatly appreciated

View attachment 972542I dont have pics of him/her dancing.. but attached is a pic of the fish dong the "dancing"

He is in my office (at work) we dont have a high traffic here there is usually just 3 or 4 of us here and most of the time everyone is in their office - he is sort of in my area so I see him more than others. He does seem to be chasing himself... When he gets to the ends he will really skim from top to bottom pretty fast.
Thank you all for your input. I've been very happy with these guys. I actually got the Yellow first w/two peacocks and he made quick haste at ridding the tank of them.. but when I but this GT/Gold Saum in w/him he became quite the submissive lil thang! *LOL*
They all seem to be getting along pretty well and neither of the cichilds seem to pay any attention to the placo... they just let him do his thing and sometimes swim under his tail. But he is at MINIMUM 4 times their size *LOL*

oops! Thanks for the spelling corrections (and the education) I'm just very glad they havent messed w/him all the teenyboppers at the pet chain assured me he would be dead in a week living with "Sampson" (the GT/Gold Saum) and "Bruce" the killer Electric Yellow that had already 2 deaths under his fin....