A. Trifasciata

[Rey82]

Today I feed my apistos small pieces of live red worms. My a. trifasciata male did a unusual act I have never seen. He swam sides ways then turned over. He did this when the female got too close to his piece of red worm. Has anyone ever seen this form of acting. I know that he isn't sick because he stopped doing it once the female swam away.

 

[Graham]

Seems like a variation on a normal territorial display.
Apistos do all kinds of weird side-swimming and flashing to "tell" others to stay away.

 

[beleg]

My female A.agassizi even swims upside down and her eyes color change so intensely that even the snails know that she is pissed off

 

[Apistomaster]

These are examples of what animal behaviorists call agonistic displays.
Fish, birds and reptiles all share this behavior.
The dwarf cichlids, especially Nannacara anomala, have had a lot of earlier work in this area done with them in labs.
They used to be a favorite subject of study 40 years ago.