Weedy seadragons courtship, Sydney, Australia

A rare sighting of the courtship between two weedy seadragons (phyllopteryx taeniolatus), photographed in the wild (Botany Bay, south Sydney, Australia).
After mimicking each other's movements for a while, with tail twists and other specific movements, they may initiate an upwards spiral, during which they would fertilize and exchange eggs, which the male would carry afterwards. The courtship started at dusk and continues during the night.
To minimize any disruption to the ritual I had turned off my dive lamp, and was shooting in near-dark, trusting the camera's autofocus to see better than I did.
The following day I came back in the same spot, and was pleased to see the ritual was successful, as the male was carrying freshly fertilized eggs.