Basic Information on the European Cuttlefish -Sepia officinalis
The cuttlefish is any cephalopod mollusks that have 10 tentacles or arms, 8 of which have muscular suction cups on their inner surface and 2 that are longer and can shoot out for grasping prey, and a reduced internal shell embedded in the enveloping mantle. The body is short, broad, and flattened. Cuttlefish are carnivorous and excellent at capturing prey with their arms. Although good swimmers, they are not as fast as the related squid. But like the squids cuttlefish have lateral fins used as stabilizers and for steering and propulsion. They swim by jet propulsion, forcibly expelling water through a siphon. During the day they lie buried in the bottom of the ocean; at night they swim and hunt for food.
The Nervous system of the European Cuttle Fish -Sepia officinalis
The cuttlefish has the most complex nervous system among invertebrates with highly developed neural organs that allow them to learn and remember. The cuttlefish pupil is a smoothly-curving W shape. Although they cannot see color, they can perceive the polarization of light, which enhances their perception of contrast. They have two spots of concentrated sensor cells on their retina (known as fovea), one to look more forward, and one to look more backwards. The lenses, instead of being reshaped as they are in humans, are pulled around by reshaping the entire eye in order to change focus. The cuttlefish has a skin comprising three layers of chromatophores (color pigment cells)—a bright yellow layer near the surface, under which is an orange-red layer and finally a dark base. Transformation from one colour to another, which can take less than a second, is controlled by the nervous system. In just a few seconds, it can run a whole gamut of colors.