There are three kinds of light emitting organs.

Firstly there are many on the surface of the skin, especially on the underbelly, or ventral side. There are about 1000 in all. The same kinds are on the syphon, head and ventral side of the third and the fourth arms.

The second type are around the eyes. Each eye has 5-surrounding it. These light organs, which are under the skin, are whitish in colour. They are easily seen through the skin because they are quite large.

The third kind are on the tip of the fourth arms. These look like black sesame seeds in shape. They emit a bluish white light that is actually stronger than a firefly. Because of their brightness, you can read a newspaper comfortably at a distance of 16 centimetres from the squid.