Fakarava, Black fin shark with pry in mouth followed bay grey reef sharks while marbled groupers mating

undersea black fin shark grey shark marbled grouper fish mating hunt eat frenzy reproduction schooling pass Fakarava Tetamanu ocean tropical Polynesia Poisson loche marbrée rassemblement requin gris frénésie requin fraie chasse requin bordé banc passe ocean Pacifique sous marin Polynésie