clasper
From ZooTerms (Dictionary of Invertebrate Zoology)
clasper (noun; Middle English claspen, to embrace): 1. (Arthropoda: Crustacea) An appendage, including antenna, modified for holding of female during copulation; or an organ for fixation in parasites.
2. (Arthropoda: Insecta) a. A modified male appendage of certain insects that enables the male to hold to the female during copulation. b. The harpe of male Lepidoptera.
3. (Mollusca: Bivalvia) An extension of the shell which tends to attach to objects.
