Cephalines

A Cephaline is any member of the Mollusc class Cephalidae, characterised by a symmetrical body, a prominent head and ear lobes, and a modification of the mollusk foot, a muscular hydrostat, into the form of arms or tencacles.

Distribution:

Cephalines are found all over the world. Of the two extant subclasses, Nautilinea and Coleorinea, there are well over 800 distinct species, with new species constantly being found. They are intolerant to brackish water and freshwater, and require salt water to survive and thrive. Cephalines occupy most depths of the oceans, such as a deep sea, hydrothermal vents, and the surface.

Nervous System and Behavior:

--Vision
Most cephalines rely on their vision to find prey and detect predators. Cephaline vision is very acute, and can distinguish the brightness, size, shape and orientation of objects. Surprisingly, given their ability to change color, most Cephalines are color blind, with only a few species exhibiting the ability to see color.

However, unlike other cephlolines, the Nautiline's vision is very poor, instead relying on its hearing the detect predators and prey.

--Hearing
Cephalines use their statocyst (balance organ) to detect sound.

Use of Light:

Most Cephalines possess Chromatophores, colored pigments, which they can use in a startling array of fashions, patterns, and colors. As well as providing camoflague, some species also use coloful displays to attract mates.

Physiology;

--Mouth
One may think a Cephaline has but one mouth, located on its mantle, however this is a common misconception. All Cephlines have two mouths, one used pureply for communication, on the mantle, and one in its center, a beak, hidden by its tentacles.