Marty’s photo of the day #4979: This is a finescale triggerfish. They can swim forward, backward, or hover by rippling their dorsal and anal fins. They have 8 strong teeth in each jaw, allowing them to crush sea urchins, crustaceans, and mollusks. Their teeth grow throughout their lives, requiring them to chew hard materials to keep them filed down.
(Photographed last month in the Galapagos Islands.)