The spotted moray eel is solitary and feeds during the day.
She keeps her mouth open but closes it occasionally, possibly to get the water through her gills and improve her oxygen supply.
The tiger shark has slender marks similars to the lines of tigers, hence its name.
When it is juvenile, these marks are round and not vertical. They change when it grows.
Parrotfish create a protective envelope around them when they are sleeping.
So, don't put the light on them during night dive to don't to wake them up and break this envelope.
Some sharks can stay motionless on the sand (white tips reef sharks, nurse sharks, etc.).
These sharks don't have to swim to bring oxygen to their gills like other sharks (grey, hammerheads tc.)