Litoria serrata (Green-eyed Tree Frog)
IUCN Status: Not assessed.
Amplexus is the work used to describe this sort of mating behaviour. The male (on top) grasps the female, and fertilises the eggs externally as she lays them. Most other external fertilisation is a matter of eggs and sperm being released freely, with no guided physical contact.
Also notice the considerable difference between the male and female. As I've said elsewhere, this is called sexual dimorphism.