European squid propulsion. The posterior border is slightly concave. The head is relatively small and has large eyes which are covered with a transparent membrane. Like almost all squid, this species has ten limbs surrounding the mouth and beak: eight are relatively short arms, and two, which form the tentacles, are long, as they are used to catch prey. The fourth left arm of males is a hectocotylus. The European squid can grow up to 30–40 cm in the mantle length, but more usually they are 15–25 cm long. The males are generally bigger than the females and exhibit more rapid rates
Striped flying squid are small subcutaneous photophores on the underside of mantle, head and of the third and fourth arms, while the fourth arms have a large oval photophore at their bases and another hallway to their tips. The ventral surface of mantle has 2 stripes of luminous tissue extending along almost its entire length with two large, oval-shaped luminous patches at the end of each mantle strip closest to the head. The fins are heart-shaped and taper to a point. The larvae have dispersed large brown chromatophores while in the juveniles these are crimson and brown. The striped flying squid is distributed