Jealous fish

[DirtyDutch]

My mom and dad have a 70 gallon planted tank with 7 Stendkers all different shades at their house. Well they have become quite confident because of handfeeding beefheart, and there's no problem when doing that. However my dad likes to 'pet' his discus sometimes, but the brilliant turqouise seems to be a little jealous, in the sense that he starts shivering and sometimes pecking the other discus when they come to close to his hand. He's also the one that loves to get 'pet' and swim through his open hand rubbing his belly the most. Has anyone ever noticed this behavior in any way with their fish?

[oldfar]

I find this very interesting some body should chime in on this ,really cool man (old hippie speak ).

[a volar]

That's kind of common thing, specially hand feeding...... peting discus is not so common but a lot of people does it, now, discus getting jealous? that I haven't hear about it.

[PAR23]

I pet my guys during feeding and WC.......I am not sure fish have the ability to feel/express jealousy