This ray hunts in the sand and moves by waving its wings.
It has a dart along its tail, which can be dangerous in case of bites on the man, but the blue spotted stingray don't attack, just be careful and don't hurt it.
This ray breathes through the top of the head and exhales from the bottom, allowing it to not suck sand.
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.
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.)
Mammals have a horizontal tail.
Fishes have a vertical fin.