Spined pygmy shark

The spined pygmy shark ("Squaliolus laticaudus") is one of the smallest sharks in the world. It is only seven to eight inches long on average. Spined pygmy sharks are dark gray or black on top. Their bellies glow in the dark. These sharks live very deep in the water (down to 6,500 feet) but they migrate up to about 650 feet at night, to hunt.
Spined pygmy sharks are harmless to humans.