The urinary and reproductive tracts join together to form the urogenital sinus. From there the sperm is eventually released into the groove of the claspers and is then delivered to the female during copulation. The internal ovaries are found anteriorly in the body cavity and are paired, but as was the case with the male testes the left side is often reduced. Indeed, the left ovary often releases very few or no eggs. Once eggs are released and fertilized, a horny shell or membrane is secreted around each one as they pass through the oviducal gland or shell gland .
Some sharks produce a shell that is tough and can protect the young.
In other species the membrane is slight or vestigial and the young develop and hatch within the uterus of the female. The eggs and egg cases produced by different species are highly variable. Eggs can be up to 60 or 70 mm in diameter and encased in shells up to 300 mm long. Shapes vary from spindle to purse-like with tendrils and hooks. During copulation sharks meet face to face.