Ink sac

As the ink bag body is referred to in the "ink" is stored for cephalopods. The ink may, if the animal feels threatened, are expelled through a funnel. The cuttlefish can bring so behind a colored cloud water by fleeing to safety.

Ink bag are also delivered to fossil in exceptional cases. The brown writing ink ( sepia) is named after the ink of cephalopod same name.

• Malacology