Rare photos of sharks having sex

Incredibly rare images show a pair of reef sharks enjoying a moment of passion off a coral reef in the Pacific Ocean.

In the images, the lovers are turned upside down, or rather fins up, as the male shark bites the female's pectoral fin, inserting his "clasp" into her cloaca - the shark's genitals. This biting ritual is used to keep the female in position during the mating process - and is common in some shark species.

Underwater photographer Ron Watkins, who captured the stunning images off the coast of Cocos Island in Costa Rica, said:

The lovers were pictured with their snouts entwined upside down on the seabed. The following images show the male shark biting the female's pectoral fin and inserting his pterygopodia into her cloaca

This biting ritual is used to keep the female in position during the mating process - and is common in some shark species.

One of the reproductive features of sharks that distinguishes them from bony fish is internal fertilization. The male fertilizes the egg directly in the female's body, introducing the reproductive organs - pterygopodia - into her cloaca. Pterygopodia are modified rays of the ventral fins of a male shark.