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
Cephalopod limb infundibulum and acetabulum causes attachment and detachment. Many octopus arm anomalies have been recorded, including a 6-armed octopus (nicknamed Henry the Hexapus), a 7-armed octopus, a 10-armed "Octopus briareus", one with a forked arm tip, octopuses with double or bilateral hectocotylization, and specimens with up to 96 arm branches. Branched arms and other limb abnormalities have also been recorded in cuttlefish, squid, and bobtail squid. Cephalopod limbs and the suckers they bear are shaped in many distinctive ways, and vary considerably between species. Some examples are shown below. For hectocotylized arms see hectocotylus variability. Cephalopod limb All cephalopods possess flexible