Yellow-edged moray (Gymnothorax flavimarginatus)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Anguilliformes · Family: Muraenidae · Genus: Gymnothorax.

Accepted name: Gymnothorax flavimarginatus · Authority: (Rüppell, 1830) · Taxonomic status: accepted · AphiaID: 217495.

Synonyms and superseded combinations recorded for this taxon: Gymnothorax flavomarginatus (Rüppell, 1830); Gymnothorax mauritianus (Kaup, 1856); Gymnothorax viridipinnis Bliss, 1883; Gymnothorax viridipinnnis Bliss, 1883; Lycodontis flavimarginatus (Rüppell, 1830); Lycodontis flavomarginatus (Rüppell, 1830); Lycodontis lemayi Smith, 1949; Muraena flavimarginata Rüppell, 1830; Muraena mauritiana Kaup, 1856; Muraena viridipinna Seale, 1917; Muraena viridipinnna Seale, 1917.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=217495 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Gymnothorax flavimarginatus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 240 cm · Depth range: 0–150 m · Habitat zone: reef-associated · Body shape: eel-like · Vulnerability index: 90 of 100 · Fishery importance: commercial · Aquarium trade: commercial.

FishBase notes: Along drop-offs (Ref. 48635). Benthic (Ref. 58302). Occurs in coral or rocky areas of reef flats and protected shorelines to seaward reefs. Feeds on cephalopods (Ref. 30573), fishes, and crustaceans (Ref. 89972). Most often appears on the reef after a fish has been speared during daylight. The regularity and promptness of such appearances make it clear that G. flavimarginatus is especially sensitive to stimuli emanating from an injured or stressed fish (Ref. 13550). Eaten in some parts of the Indo-Pacific (Ref. 12484). Minimum depth reported taken from Ref. 128797. Solitary and curious, usually seen with head protruding (Ref 90102).

Source: FishBase species summary (SpecCode 5392) — https://www.fishbase.se/summary/Gymnothorax-flavimarginatus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

3,158 georeferenced occurrence records for Gymnothorax flavimarginatus are published through GBIF from 75 countries or marine areas. The map above plots 455 distinct locations from a sample of 3,000 records, omitting 56 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: United States of America (848); Indonesia (416); Egypt (169); Philippines (165); Maldives (138).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2404084) — https://www.gbif.org/occurrence/search?taxon_key=2404084&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=217495 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Gymnothorax flavimarginatus (Rüppell, 1830) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 195728) — https://www.iucnredlist.org/species/195728/0; GBIF IUCN Red List category endpoint (taxonKey 2404084) — https://api.gbif.org/v1/species/2404084/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Moray eels are long slender fish with bulbous heads, rounded snouts and gradually tapering tails. The large mouth contains a single row of small pointed teeth in the lower jaw and several vomerine teeth on the roof of the mouth. The dorsal fin extends continuously from just behind the head along the back to round the tail, where it continues as the caudal and anal fins. The yellow-edged moray can grow to a maximum length of about 240 cm, but a more typical length would be 80 cm. It is basically a dull yellow colour with a mottled pattern of dark brown or black covering most of the surface. The head is a purplish-grey and there is a large black blotch at the operculum. The margins of the fins on the posterior part of the body are yellowish or greenish. Young fish may have a brighter yellow background colour with brown blotches.

The yellow-edged moray occurs in the tropical Indo-Pacific region. Its range extends from East Africa and the Red Sea to Japan, Indonesia and Australia, and on to the Ryukyu and Hawaiian islands, New Caledonia and on to Costa Rica, Panama and the Galápagos Islands. Its typical habitat is coral or rocky areas of reef flats and the protected sides of seaward reefs, ranging down to a depth of about 150 m.

The yellow-edged moray is usually a solitary fish, tending to hide in a crevice or submerged in the sediment with just its head protruding. Sometimes it shares its shelter with conspecifics or with other moray eel species. It is mainly nocturnal, but also swims around freely in the morning and evening. Fish, cephalopods and crustaceans are included in its diet. If a fish is speared on the reef, these moray eels are quick to appear, being sensitive to stimuli emitted by injured or stressed fish. This moray eel was recently identified as a natural predator of the lionfish Pterois miles in its native habitat in the Red Sea. The shrimp-like crustacean Stenopus pyrsonotus, has often been found in close proximity with a yellow-edged moray eel, leading to the possibility that the shrimp may enter into a cleaning symbiosis with the eel.

Source: Wikipedia: Yellow-edged moray — https://en.wikipedia.org/wiki/Yellow-edged_moray (CC BY-SA 4.0). Accessed 2026-09-23.