Here’s an amazing video we took, showing the mating behaviour of surgeonfish on the Milaidhoo house reef last December, just before Christmas. The fish can be observed in what is known to be the typical mating behaviour of surgeon fishes (Acanthuridae).
Surgeon fishes, as all bony fishes (Osteychtyes), reproduce sexually by external fertilization releasing their reproductive cells (gametes) in the water column.
During their mating bouts females swim upward above the reef top and release their eggs, every male in the close vicinity sprints upward following the female and releases its sperm. In this clip gametes can be clearly seen in the form of a white dusty cloud.
Posted by Fabio: marine biologist