You searched for: “hectocotylus”
hectocotylus (s); hectocotyli (pl)
A modified arm of the male of certain cephalopods, such as the octopus, functioning as a reproductive organ in the transference of sperm to the mantle cavity of the female. It is a specialized, extended tentacle used to store spermatophores, the male gamete. Males generally form a new hectocotylus in each new season.