Lungfish yawning

[fwlion]

my MAL does alot of yawning why is this I know cichlids "yawn" to get gravel out of their gills after they have been digging but why do lungfish yawn alot

he hasn't starting digging or anything YET

 

[channarox]

lungfish tend to do this.
excercising their mouths?
it seems very normal.