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.
We can hear the bull shark is very dangerous because of attacks near La Réunion island.
However, tens of them are living at 600 feet from the famous beach of Playa Del Carmen in Mexico. And there are no attacks.
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.