Description:

Dorsal spines: 0; Dorsal rays: 0; Anal spines: 0; Anal rays: 0.

A  moderate  length  species  of  Gymnothorax with anus before mid-body, small tubular anterior nostrils and slightly raised posterior nostrils. Gill opening 
nearly horizontal, its centre slightly below mid-body, its length about equal to diameter of eye. Jaws subequal, the mouth closing completely. Vomerine 
teeth either absent or few. Teeth in jaws uniserial, nearly subequal, stout, pointed, and finely serrated. Two depressible long canines along mid-line of 
intermaxillary, the posterior the largest tooth in the mouth. Three pairs of depressible canines behind mandibular symphysis.

Colour. Brown body with darler speckles. Distinctive black areas behind the eye, at the rictus, and over the gill opening. A black spot smaller than the 
eye present beneath the rictus of some specimens. Margin of caudal cream, yellowish in life. 
 

Maturity: Unknown. Max length : 100.0 cm TL.
 

Inhabits seaward reefs of oceanic islands (depth 4–40 m). Associated with steep slopes and reef walls, usually only exposing head from coral holes. 
Territorial and aggressive. Feeds on small fishes and octopi.
 

This species is not protected or subject to fishery regulations. It does not appear to be subject to the artisanal fishery.

Photo courtesy Eleanor Brighton and Chris Mason-Parker (c) 2022 Blue Safari Seychelles/Marine Conservation Society, Seychelles. 
Photograph taken at Alphonse group 2022.
Photo courtesy of Green Islands Foundation (c) 2023 at Denis island.  
This species was first recorded in Seychelles by Randall & van Egmond (1994) at Bird Island in 1992 and at Alphonse in 1993.

Bray, D.J. Gymnothorax breedeni in Fishes of Australia, https://fishesofaustralia.net.au/home/species/4948 (17/08/23)
Castle, P.H.J. & McCosker, J.E. (1986). Muraenidae. p. 165-176. In M.M. Smith and P.C. Heemstra (eds.) Smiths' sea fishes. Springer-Verlag, Berlin.
Froese, R. & D. Pauly. (Eds.) (2023). FishBase. Gymnothorax breedeni https://www.fishbase.se/summary/7881 (16/08/23).
Mason-Parker, C. et al. (2021). Gymnothorax breedeni in Reef Fishes of Seychelles. John Beaufoy Publishing Ltd, UK. 
McCosker, J. E. & Randall, J.E. (1977). Three New Species of Indo-Pacific Moray Eels (Pisces: Muraenidae). Proc. Calif. Acad.Sci., 4th Ser., Vol.41, No. 3, pp. 161-168. 
Randall, J.E. & van Egmond, J. (1994). Marine fishes from the Seychelles: 108 new records. Zool. Verh. Leiden 297:43-83.
Smith, D.G. et al. (2019). Gymnothorax breedeni. The IUCN Red List 2019: https://dx.doi.org/10.2305/IUCN.UK.2019-1.RLTS.T195712A2406583.en. (16/08/23).

Nevill, J.E.G., Brighton, E. & Mason-Parker, C. (2023). Gymnothorax breedeni, Blackcheek moray. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/gymnothorax-breedeni-mccosker-randall-1977/ (Updated 29/10/23).