The Threadfin Butterflyfish is a reef-associated fish and its does not migrate. Its depth range is 1-35 meters / 3-115 feet. It can be found in several different types of habitats, including corals reefs, inshore waters and rubble covered bottoms with prolific plant and algae growth.
I have seen and photographed this fish many times in the Red Sea.
The yellowstripe goatfish is a species of goatfish native to the Pacific Ocean and the Indian Ocean. The name of the fish in latin is Mulloidichthys flavolineatus.
The goatfish belong to the Mullidae family and rank among the common fish in the Red Sea.
Their peculiar barbels are though not so common. These barbels can be spotted beneath the chin on either side of the mouth. These barbells function as sensitive filaments to trace molluscs, crustaceans and worms. The goatfish are nocturnal, which means they swim around mostly at night.
The initial phase has very variable coloration. The smaller fishes can be a dark brown to light gray and they may or may not possess a light band surrounding a dark spot on the caudal peduncle.
Larger fish can show a series of irregular rows of small, light spots towards the tail or they may have the light band surrounding the dark spot on the caudal peduncle. The terminal phase, male, is also variable and may have a large tan area on the flanks or on its caudal peduncle. It has a rounded snout.
Chlorurus sordidus is widespread throughout the tropical waters of the Indo-Pacific region, Red Sea included.