Clasper

File:Wobbegong claspers.jpg

The claspers of a spotted wobbegong shark (Orectolobus maculatus)

File:Carcharhinus brevipinna JNC3077 Male parts.JPG

The claspers of a young spinner shark (Carcharhinus brevipinna)

File:Ischyodus quenstedti or egertoni.png

Life restoration of the extinct chimaera Ischyodus, showing the presence of a cephalic clasper on the head of males (as well as a pelvic clasper) but absent in females

In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating.

File:Spotted Ratfish Clasper.png

A close up view of a chimaera clasper (Hydrolagus collie). Note the many small tooth-like projections covering the exterior surface.

File:Harpagofututor volsellorhinus.png

Illustration of Harpagofututor an extinct chimaera-relative in which males (below) had clasper structures on their heads

Male cartilaginous fish have claspers formed from the posterior portion of their pelvic fin which serve to channel semen into the female's cloaca during mating. The act of mating in some fish including sharks usually includes one of the claspers raised to allow water into the siphon through a specific orifice. The clasper is then inserted into the cloaca, where it opens like an umbrella to anchor its position. The siphon then begins to contract, expelling water and sperm.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite book</ref> The claspers of many shark species have spines or hooks,<ref>Template:Cite book</ref> which may hold them in place during copulation.<ref>Template:Cite book</ref> Many male holocephalans, including living chimaeras, have cephalic claspers (tenacula) on their heads, which are thought to aid in holding the female during mating.<ref name=":0">Template:Cite book</ref>

In entomology, it is a structure in male insects that is used to hold the female during copulation (see Lepidoptera genitalia for more).

See also

• Sexual coercion among animals