AMAZING CUTTLEFISH - Cephalopods with Natural Camouflage and Sepia InkHome

Cuttlefish Features

Special Features of the cuttlefish include:

Eyesight

Cuttlefish eye Cuttlefish have very good eyesight. They have binocular vision as the visual fields for both eyes overlap. Cuttlefish have W-shaped pupils that contains a lens that is similar to humans but focuses in a different way.

To focus on close objects, the cuttlefish contracts the muscles around the eye which pushes the lens forward, away from the retina. To focus on distant objects, the cuttlefish relaxes the muscles and draws the lens inward.

Minute hairs along the cuttlefish head and tentacles detect low frequency vibrations. This enables them to 'hear' and locate their prey.

Movement

Cuttlefish move by gently undulating their skirt-like fins. They glide smoothly through the water and can vary their depth easily. The cuttlefish bone is a porous, gas-filled chambered shell which gives the cuttlefish neutral buoyancy.

cuttlefish swimming        cuttlefish swimming

To rise or sink in the water, the cuttlefish varies the proportion of liquid to air ratio within the cuttlefish bone. The more liquid in the cuttlebone, the lower the cuttlefish sinks in the water.

For fast movement through the water, the cuttlefish uses a form of "jet propulsion'.It draws water into the mantle cavity through the mantle opening and then contracts the mantle muscles which forces the water back out through the siphon. The cuttlefish then shoots away. The siphon is flexible and can be swivelled into different directions in order to steer.

Fleeing

When a cuttlefish is threatened, it has three ways to escape:

  1. It can sink to the bottom, rapidly pump water out through the siphon and then bury itself in the disturbed sand.
  2. It can pump water out of the siphon and propel itself backwards.
  3. It can pump a protein-based sepia ink out of the siphon and escape during the confusion. The sepia ink may be produced as a mucus-bound blob or as a large cloud.


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Web-site last revised (June 2006) Copyright