These cephalopods have eight "normal arms," along with a pair of retractile arms with clubbed suckers on the ends. Their torpedo-shaped, stream-lined bodies with terminal fins often appear somewhat blunter and wider as their depth increases, and enclose a thin membraneous internal shell. The two fins comprise a length of approximately two-thirds of the organism's body and produce a diamond-shape when seen from the dorsal view. These squid have well-developed heads with large eyes that are useful in predation. These squid possess colors and stripes; colors change during the escape mechanisms to a pink, red, or brown hue.
Range length: 12 to 90 cm.
Average length: 40 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry