primary sexual organ of male animals

A penis (plural penises or penes /-nz/) is the main sexual organ that male animals use to inseminate females (or hermaphrodites) during sex.[1] It is also used to urinate.

The penis of an Asian elephant

Such organs are found in many animals, both vertebrate and invertebrate, but males do not always have a penis in every species, and in those species in which the male does have a so-called penis, the penises in those species are not homologous.


  1. Janet Leonard; Alex Cordoba-Aguilar R (18 June 2010). The Evolution of Primary Sexual Characters in Animals. Oxford University Press. ISBN 978-0-19-971703-3. Retrieved 20 July 2013.