Hectocotylus

A hectocotylus is an arm in male cephalopods, which serves the purpose of reproduction and has special architectural features.

The tentacle is used to fertilize the female egg and is constructed so that it contains the spermatophores of males and emits during mating. Usually the hectocotylus is formed in each new mating season again.

The shape of the arm varies among individual species, although many of them have similar specifications to certain forms. In Haliphron atlanticus ( Seven- Octopus ) about the hectocotylus is stored in a small cloth bag near the right eye, which leads to the outside to the apparently seven- show.

A special case is the hectocotylus the paper boat Argonauta. Fertilization takes place through the arm of the male places the spermatophores in a cave in the shell of the female, but has no direct contact to occur, the arm is able to move away from the male and independently to swim to the female. Strange is at this point that the separated hectocotylus was held by its namesake Georges Cuvier originally for a parasite on females before they could assign it to the males. However, the arm was already in the biological works of Aristotle described, but held until his rediscovery in the 19th century, a myth.