No pectoral or pelvic fins, only one dorsal, caudal and anal fin.
No scales, the body is covered with a protective mucus.
This moray eel is solitary, but it often stays with cleaning shrimp with which it shares its meals and offers protection in exchange for deworming.
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.)
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.
Turtles are in economy mode when they are sleeping. If they are woken during night, they may not have enough air to return to surface.
So, please be careful during night dives!