Fish yawning or something else ?

My senegal bichir yawn at a certain of time I don't know if this is normal ? Secondly, why do they yawn ???

 

Some fish appear to yawn..but they are actually flushing their gills. There are also times that a fish will expand his mouth which looks like yawning... to show dominance!
However....It's more fun to think that they are just a little sleepy!

 

Thks

 

So its normal ?

 

Absolutely! Make sure you say good night to them,,,just in case!

 

Haha thks