Cuttlefish, the second type of cephalopods included in this report, are also very interesting. Approximately 100 species of cuttlefish are known, spread widely in most of the oceans of the Tropic and Temperate zones. They normally range in size from 15-25 cm. However, the largest varieties reach a length of 61 cm. Cuttlefish have flattened bodies and are actually not fish at all because they lack a back bone.
Cuttlefish have a mouth with arm-like tentacles arranged in pairs around it.
These help to move food into the mouth. Cuttlefish also have two longer arms which they actually use to capture food. Cuttlefish normally swim by moving a narrow fin that extend along the entire length of the body on both sides. This pulsates rhythmically to move the water. Cuttlefish can also move at high speed in the same way that squid do that have a funnel-like tube behind there head that they can also use to propel themselves through the water.