Dwarf moray (Gymnothorax melatremus)
Source-cited species reference: taxonomy from WoRMS, biology from FishBase, occurrence map from GBIF, conservation from IUCN Red List, description from Wikipedia.
Gymnothorax melatremus, the blackspot moray, dirty yellow moray or dwarf moray, is a moray eel from the Indo-Pacific East Africa to the Marquesas and Mangaréva, north to the Hawaiian Islands, south to the Australs islands. It rarely makes its way into the aquarium trade.
- Scientific name
- Gymnothorax melatremus
- Authority
- Schultz, 1953
- Family
- Muraenidae
- Order
- Anguilliformes
- Maximum length
- 30 cm
- Depth range
- 1–58 m
- Habitat zone
- reef-associated
- Iucn red list
- Least Concern
- Gbif occurrence records
- 753
Classification (WoRMS)
Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Anguilliformes · Family: Muraenidae · Genus: Gymnothorax.
Accepted name: Gymnothorax melatremus · Authority: Schultz, 1953 · Taxonomic status: accepted · AphiaID: 217481.
Synonyms and superseded combinations recorded for this taxon: Lycodontis melatremus (Schultz, 1953).
Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=217481 (CC BY 4.0). Accessed 2026-09-23.
Biology and life history (FishBase)
Measured values published by FishBase for Gymnothorax melatremus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.
Maximum length: 30 cm · Depth range: 1–58 m · Habitat zone: reef-associated · Body shape: eel-like · Vulnerability index: 20 of 100 · Fishery importance: minor commercial · Aquarium trade: never/rarely.
FishBase notes: Benthic (Ref. 58302). Lives in holes and crevices of seaward reefs from the surge zone to over 26 m. Solitary and secretive in reef crevices; seldom seen (Ref 90102).
Source: FishBase species summary (SpecCode 7284) — https://www.fishbase.se/summary/Gymnothorax-melatremus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.
Distribution and occurrence records (GBIF)
753 georeferenced occurrence records for Gymnothorax melatremus are published through GBIF from 32 countries or marine areas. The map above plots 146 distinct locations from a sample of 753 records, omitting 20 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 (284); French Polynesia (99); Philippines (45); South Africa (45); Palau (31); Australia (27); Solomon Islands (27); Comoros (23); Indonesia (17); Papua New Guinea (17); Wallis and Futuna (17); Vanuatu (15); Seychelles (12); Christmas Island (10); British Indian Ocean Territory (10).
Marine regions with a valid WoRMS distribution record: Mauritian Exclusive Economic Zone; Seychellois Exclusive Economic Zone; South Africa (country); Chagos.
Source: GBIF Occurrence Search (taxonKey 2403885) — https://www.gbif.org/occurrence/search?taxon_key=2403885&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=217481 (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 melatremus Schultz, 1953 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 195753) — https://www.iucnredlist.org/species/195753/0; GBIF IUCN Red List category endpoint (taxonKey 2403885) — https://api.gbif.org/v1/species/2403885/iucnRedListCategory. Accessed 2026-09-23.
Description and natural history (Wikipedia)
Gymnothorax melatremus have dorsal fins originating about midway between gill opening and corner of mouth. They have small and stout teeth and no canines, with a single row of teeth at the front of upper jaw with 1–2 median teeth, then teeth in two rows on each side of upper jaw, with longer and more slender teeth in the inner row and larger teeth at front of lower jaw. They grow up to 26 cm in length. They vary in color from gold, yellow, and white throughout their bodies with black spots in their gill openings and deep blue in their eyes.
Like other moray eels, Gymnothorax melatremus is carnivorous. In the wild, it feeds on any crustaceans and small fish it can catch for example: ghost shrimp, dead squid, firefish, jawfish & etc.
This moray eel is part of the aquarium hobby and you can feed it: Dead fishes, chopped cephalopods and small shrimp.
They are mostly peaceful but they are still morays so they will attack vulnerable species like small bottom feeders and other types of small fishes. When scared or in danger it will attack and their bite can cause infections. They are mostly nocturnal so at day time they are very hard to find.
In small places they will get nervous and will be more alert to movements and prey.
Source: Wikipedia: Gymnothorax melatremus — https://en.wikipedia.org/wiki/Gymnothorax_melatremus (CC BY-SA 4.0). Accessed 2026-09-23.
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