Alex Mustard - Mandarin Moment
Mandarinfish are incredibly colourful, but extremely secretive fish, living in the dark recesses between the rubble on shallow coral reefs. Each evening they emerge to mate and this is the chance to see and photograph them. The larger males court the females and persuade them to mate by lifting them up into the water column on their pectoral fin.
This photo shows the smaller female (left) releasing a trail of eggs, which the male is fertilising (the sperm are too small to be visible).
Location: Lembeh, Indonesia