Silver Aro 7 inches, strange actions

[Fai]

My Silver Arowana 7 inches at times, will open and close mouth like its chewing gum and has been shadow boxing (tries to bite the glass) at the corner a lot these days, sometimes even in the center front of the tank. What possibly is he doing and why?

Also, when I change water, he will sink himself to the bottom of the tank and sit there till am done and start swimming around 20 mins later. think he gets the jitters with the siphoning et all. Any thoughts?

Water level is optimal, 55G.

Thanks.
Fai

 

[Kaya]

Hi Fai.. Is it more like a yawn? My aros do that if they are hungry.. super hungry.. What are you feeding the aro and how many times a day? and about the siphoning bit.. yes most aros will do the same.. I have 4 Silvers.. Couple of my aros dont mind.. they swim around and sometimes come close to my hand but the other two move away to the far corner of the tank.. just give the aro time to trust you.