Yellowtail/Purple Tang Zebrasoma xanthurum

The Purple Tang is also called the Yellowtail Tang and is native to coral reefs of the Red Sea and Arabian Gulf.

They can grow to some 25 cm (10 inches) long and have a purple body with darker spots on the front end, yellow-tipped fins and a bright yellow tail.

Some can look almost black (unless these are something else). Diet is marine algae and seaweed.