Nautilus is a general term for marine mollusks in the family Nautidae, belonging to the order Cephalopoda. There are 2 genera and 6 species, with curled pearl like shells that can grow up to 26 centimeters in size, but adult parrots generally do not exceed 20 centimeters. Usually only 16 centimeters. The shell is composed of many chambers, and the outer shell is located inside the shell. There is a diaphragm separating each chamber; Two pairs of gills; 63-94 wrists, but without suction cups. The shell is thin and light, coiled in a spiral shape, with a white or milky white surface. The growth lines radiate from the navel of the shell, smooth and fine, mostly reddish brown in color. The entire spiral shell is smooth like a disc, resembling a parrot's beak, hence the name "Nautilus".