Yellow-edged Moray

The Yellow-edged Moray (Gymnothorax flavimarginatus) is a large member of the moray eel family, Muraenidae, widespread across the tropical Indo-Pacific from East Africa to Hawaii and French Polynesia. It is among the bigger reef-dwelling morays, with confirmed lengths approaching 2.5 meters, and is a common sight to divers exploring reef flats and lagoons. Like all morays it lacks pelvic and pectoral fins, moving with an eel-like undulating swim. It is not currently considered threatened and remains abundant throughout its extensive range, occupying a wide depth band from shallow tide pools down to around 150 meters.

Recognize this species by its size and pattern:

• Dark brown to blackish body densely covered in small pale yellow-white spots that merge into a mottled, maze-like network
• Continuous dorsal fin running the length of the back, edged in bright yellow
• Large, muscular body reaching 1-2.5 m, thicker than most reef morays
• Blunt snout with strong jaws and visible tubular nostrils
• No scales, pectoral, or pelvic fins, typical of Muraenidae It is distinguished from the similarly patterned Undulated Moray by its finer, denser spotting and the diagnostic yellow dorsal-fin margin.

This moray inhabits coral and rocky reefs throughout the tropical Indo-Pacific, from shallow lagoons and reef flats to outer reef slopes down to roughly 150 meters depth. It favors crevices, caverns, and holes among coral heads and rubble where it can wedge its long body and expose only its head. Juveniles and adults are found from intertidal reef pools to deeper fore-reef habitats, and the species tolerates a wide range of reef structures, including both clear oceanic reefs and more turbid coastal reef systems across its Indo-Pacific range, which stretches from the Red Sea and East African coast eastward to the central Pacific islands.

Yellow-edged Morays are solitary, territorial predators that spend daylight hours concealed within a chosen den, with only the head protruding while they open and close their jaws to pump water over the gills. They become active at dusk and during the night, hunting fish, crustaceans, and cephalopods using strong olfactory senses rather than eyesight. Like other morays they possess a second set of jaws in the throat (pharyngeal jaws) that pull prey into the esophagus. They occasionally form loose associations with cleaner shrimp or wrasses that groom parasites from their skin, and larger individuals may cohabit reef sites with groupers in cooperative hunting encounters.