In males, they facilitate the transfer of sperm from male to female during mating, and thus are a type of intromittent organ. In crustaceans and millipedes, gonopods are modified walking or swimming legs.
In males, they facilitate the transfer of sperm from male to female during mating, and thus are a type of copulatory organ. In crustaceans and millipedes, gonopods are modified walking or swimming appendages.