Red Devil stretches his mouth...

[Skyla]

This normal?

Ha ha, I mean he does it pretty often and Im a worry wort. I just want to be sure its not an indication of anything.

 

[Pocoloco]

my arowana does it also, seems like a yawn or something lol but hes been fine

 

[Skyla]

Thats exactly what it looks like! Like hes yawning lol

 

[AcsFoolMike]

Perfectly normal...my GT does it all the time

 

[Red devil 1985]

Thats exactly what it looks like! Like hes yawning lol

It is like a yawn, my red devil does it too, so do my other fish. It is kind of funny to see.

 

[Amphilophus88]

Most of my fish do it as well.

 

[siebertn]

As I understand it they flush water over there gill plates to clean it(backwash there gills)

 

[dadfish123]

My Koi does this

Posted on mobile.monsterfishkeepers.com

 

[Royaldoa]

i always thought it was to see how big of fish they can fit in their mouth.. lol

 

[pjsmetana]

Unless they are doing it in the direction of another fish, they are just stretching/gill cleaning (or brushing their teeth, as I call it). If it is in the direction of another fish, then its a sign of aggression, and may fight until death or until dominance/submission.